6738 lines
201 KiB
C
6738 lines
201 KiB
C
/* Common target dependent code for GDB on ARM systems.
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Copyright (C) 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1998, 1999, 2000,
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2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
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Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include <ctype.h> /* XXX for isupper () */
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#include "defs.h"
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#include "frame.h"
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#include "inferior.h"
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#include "gdbcmd.h"
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#include "gdbcore.h"
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#include "gdb_string.h"
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#include "dis-asm.h" /* For register styles. */
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#include "regcache.h"
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#include "doublest.h"
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#include "value.h"
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#include "arch-utils.h"
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#include "osabi.h"
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#include "frame-unwind.h"
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#include "frame-base.h"
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#include "trad-frame.h"
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#include "objfiles.h"
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#include "dwarf2-frame.h"
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#include "gdbtypes.h"
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#include "prologue-value.h"
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#include "target-descriptions.h"
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#include "user-regs.h"
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#include "arm-tdep.h"
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#include "gdb/sim-arm.h"
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#include "elf-bfd.h"
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#include "coff/internal.h"
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#include "elf/arm.h"
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#include "gdb_assert.h"
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#include "vec.h"
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static int arm_debug;
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/* Macros for setting and testing a bit in a minimal symbol that marks
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it as Thumb function. The MSB of the minimal symbol's "info" field
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is used for this purpose.
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MSYMBOL_SET_SPECIAL Actually sets the "special" bit.
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MSYMBOL_IS_SPECIAL Tests the "special" bit in a minimal symbol. */
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#define MSYMBOL_SET_SPECIAL(msym) \
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MSYMBOL_TARGET_FLAG_1 (msym) = 1
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#define MSYMBOL_IS_SPECIAL(msym) \
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MSYMBOL_TARGET_FLAG_1 (msym)
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/* Per-objfile data used for mapping symbols. */
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static const struct objfile_data *arm_objfile_data_key;
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struct arm_mapping_symbol
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{
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bfd_vma value;
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char type;
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};
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typedef struct arm_mapping_symbol arm_mapping_symbol_s;
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DEF_VEC_O(arm_mapping_symbol_s);
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struct arm_per_objfile
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{
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VEC(arm_mapping_symbol_s) **section_maps;
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};
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/* The list of available "set arm ..." and "show arm ..." commands. */
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static struct cmd_list_element *setarmcmdlist = NULL;
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static struct cmd_list_element *showarmcmdlist = NULL;
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/* The type of floating-point to use. Keep this in sync with enum
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arm_float_model, and the help string in _initialize_arm_tdep. */
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static const char *fp_model_strings[] =
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{
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"auto",
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"softfpa",
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"fpa",
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"softvfp",
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"vfp",
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NULL
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};
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/* A variable that can be configured by the user. */
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static enum arm_float_model arm_fp_model = ARM_FLOAT_AUTO;
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static const char *current_fp_model = "auto";
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/* The ABI to use. Keep this in sync with arm_abi_kind. */
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static const char *arm_abi_strings[] =
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{
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"auto",
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"APCS",
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"AAPCS",
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NULL
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};
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/* A variable that can be configured by the user. */
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static enum arm_abi_kind arm_abi_global = ARM_ABI_AUTO;
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static const char *arm_abi_string = "auto";
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/* The execution mode to assume. */
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static const char *arm_mode_strings[] =
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{
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"auto",
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"arm",
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"thumb"
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};
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static const char *arm_fallback_mode_string = "auto";
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static const char *arm_force_mode_string = "auto";
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/* Number of different reg name sets (options). */
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static int num_disassembly_options;
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/* The standard register names, and all the valid aliases for them. */
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static const struct
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{
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const char *name;
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int regnum;
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} arm_register_aliases[] = {
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/* Basic register numbers. */
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{ "r0", 0 },
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{ "r1", 1 },
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{ "r2", 2 },
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{ "r3", 3 },
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{ "r4", 4 },
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{ "r5", 5 },
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{ "r6", 6 },
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{ "r7", 7 },
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{ "r8", 8 },
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{ "r9", 9 },
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{ "r10", 10 },
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{ "r11", 11 },
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{ "r12", 12 },
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{ "r13", 13 },
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{ "r14", 14 },
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{ "r15", 15 },
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/* Synonyms (argument and variable registers). */
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{ "a1", 0 },
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{ "a2", 1 },
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{ "a3", 2 },
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{ "a4", 3 },
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{ "v1", 4 },
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{ "v2", 5 },
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{ "v3", 6 },
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{ "v4", 7 },
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{ "v5", 8 },
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{ "v6", 9 },
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{ "v7", 10 },
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{ "v8", 11 },
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/* Other platform-specific names for r9. */
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{ "sb", 9 },
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{ "tr", 9 },
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/* Special names. */
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{ "ip", 12 },
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{ "sp", 13 },
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{ "lr", 14 },
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{ "pc", 15 },
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/* Names used by GCC (not listed in the ARM EABI). */
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{ "sl", 10 },
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{ "fp", 11 },
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/* A special name from the older ATPCS. */
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{ "wr", 7 },
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};
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static const char *const arm_register_names[] =
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{"r0", "r1", "r2", "r3", /* 0 1 2 3 */
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"r4", "r5", "r6", "r7", /* 4 5 6 7 */
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"r8", "r9", "r10", "r11", /* 8 9 10 11 */
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"r12", "sp", "lr", "pc", /* 12 13 14 15 */
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"f0", "f1", "f2", "f3", /* 16 17 18 19 */
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"f4", "f5", "f6", "f7", /* 20 21 22 23 */
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"fps", "cpsr" }; /* 24 25 */
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/* Valid register name styles. */
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static const char **valid_disassembly_styles;
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/* Disassembly style to use. Default to "std" register names. */
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static const char *disassembly_style;
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/* This is used to keep the bfd arch_info in sync with the disassembly
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style. */
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static void set_disassembly_style_sfunc(char *, int,
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struct cmd_list_element *);
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static void set_disassembly_style (void);
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static void convert_from_extended (const struct floatformat *, const void *,
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void *, int);
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static void convert_to_extended (const struct floatformat *, void *,
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const void *, int);
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static void arm_neon_quad_read (struct gdbarch *gdbarch,
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struct regcache *regcache,
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int regnum, gdb_byte *buf);
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static void arm_neon_quad_write (struct gdbarch *gdbarch,
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struct regcache *regcache,
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int regnum, const gdb_byte *buf);
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struct arm_prologue_cache
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{
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/* The stack pointer at the time this frame was created; i.e. the
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caller's stack pointer when this function was called. It is used
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to identify this frame. */
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CORE_ADDR prev_sp;
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/* The frame base for this frame is just prev_sp - frame size.
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FRAMESIZE is the distance from the frame pointer to the
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initial stack pointer. */
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int framesize;
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/* The register used to hold the frame pointer for this frame. */
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int framereg;
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/* Saved register offsets. */
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struct trad_frame_saved_reg *saved_regs;
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};
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/* Architecture version for displaced stepping. This effects the behaviour of
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certain instructions, and really should not be hard-wired. */
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#define DISPLACED_STEPPING_ARCH_VERSION 5
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/* Addresses for calling Thumb functions have the bit 0 set.
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Here are some macros to test, set, or clear bit 0 of addresses. */
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#define IS_THUMB_ADDR(addr) ((addr) & 1)
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#define MAKE_THUMB_ADDR(addr) ((addr) | 1)
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#define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1)
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/* Set to true if the 32-bit mode is in use. */
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int arm_apcs_32 = 1;
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/* Determine if FRAME is executing in Thumb mode. */
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static int
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arm_frame_is_thumb (struct frame_info *frame)
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{
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CORE_ADDR cpsr;
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/* Every ARM frame unwinder can unwind the T bit of the CPSR, either
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directly (from a signal frame or dummy frame) or by interpreting
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the saved LR (from a prologue or DWARF frame). So consult it and
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trust the unwinders. */
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cpsr = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
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return (cpsr & CPSR_T) != 0;
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}
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/* Callback for VEC_lower_bound. */
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static inline int
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arm_compare_mapping_symbols (const struct arm_mapping_symbol *lhs,
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const struct arm_mapping_symbol *rhs)
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{
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return lhs->value < rhs->value;
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}
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/* Search for the mapping symbol covering MEMADDR. If one is found,
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return its type. Otherwise, return 0. If START is non-NULL,
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set *START to the location of the mapping symbol. */
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static char
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arm_find_mapping_symbol (CORE_ADDR memaddr, CORE_ADDR *start)
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{
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struct obj_section *sec;
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/* If there are mapping symbols, consult them. */
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sec = find_pc_section (memaddr);
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if (sec != NULL)
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{
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struct arm_per_objfile *data;
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VEC(arm_mapping_symbol_s) *map;
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struct arm_mapping_symbol map_key = { memaddr - obj_section_addr (sec),
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0 };
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unsigned int idx;
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data = objfile_data (sec->objfile, arm_objfile_data_key);
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if (data != NULL)
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{
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map = data->section_maps[sec->the_bfd_section->index];
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if (!VEC_empty (arm_mapping_symbol_s, map))
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{
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struct arm_mapping_symbol *map_sym;
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idx = VEC_lower_bound (arm_mapping_symbol_s, map, &map_key,
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arm_compare_mapping_symbols);
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/* VEC_lower_bound finds the earliest ordered insertion
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point. If the following symbol starts at this exact
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address, we use that; otherwise, the preceding
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mapping symbol covers this address. */
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if (idx < VEC_length (arm_mapping_symbol_s, map))
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{
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map_sym = VEC_index (arm_mapping_symbol_s, map, idx);
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if (map_sym->value == map_key.value)
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{
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if (start)
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*start = map_sym->value + obj_section_addr (sec);
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return map_sym->type;
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}
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}
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if (idx > 0)
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{
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map_sym = VEC_index (arm_mapping_symbol_s, map, idx - 1);
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if (start)
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*start = map_sym->value + obj_section_addr (sec);
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return map_sym->type;
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}
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}
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}
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}
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return 0;
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}
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static CORE_ADDR arm_get_next_pc_raw (struct frame_info *frame,
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CORE_ADDR pc, int insert_bkpt);
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/* Determine if the program counter specified in MEMADDR is in a Thumb
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function. This function should be called for addresses unrelated to
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any executing frame; otherwise, prefer arm_frame_is_thumb. */
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static int
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arm_pc_is_thumb (CORE_ADDR memaddr)
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{
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struct obj_section *sec;
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struct minimal_symbol *sym;
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char type;
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/* If bit 0 of the address is set, assume this is a Thumb address. */
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if (IS_THUMB_ADDR (memaddr))
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return 1;
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/* If the user wants to override the symbol table, let him. */
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if (strcmp (arm_force_mode_string, "arm") == 0)
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return 0;
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if (strcmp (arm_force_mode_string, "thumb") == 0)
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return 1;
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/* If there are mapping symbols, consult them. */
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type = arm_find_mapping_symbol (memaddr, NULL);
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if (type)
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return type == 't';
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/* Thumb functions have a "special" bit set in minimal symbols. */
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sym = lookup_minimal_symbol_by_pc (memaddr);
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if (sym)
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return (MSYMBOL_IS_SPECIAL (sym));
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/* If the user wants to override the fallback mode, let them. */
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if (strcmp (arm_fallback_mode_string, "arm") == 0)
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return 0;
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if (strcmp (arm_fallback_mode_string, "thumb") == 0)
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return 1;
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/* If we couldn't find any symbol, but we're talking to a running
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target, then trust the current value of $cpsr. This lets
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"display/i $pc" always show the correct mode (though if there is
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a symbol table we will not reach here, so it still may not be
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displayed in the mode it will be executed).
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As a further heuristic if we detect that we are doing a single-step we
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see what state executing the current instruction ends up with us being
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in. */
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if (target_has_registers)
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{
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struct frame_info *current_frame = get_current_frame ();
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CORE_ADDR current_pc = get_frame_pc (current_frame);
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int is_thumb = arm_frame_is_thumb (current_frame);
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CORE_ADDR next_pc;
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if (memaddr == current_pc)
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return is_thumb;
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else
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{
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struct gdbarch *gdbarch = get_frame_arch (current_frame);
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next_pc = arm_get_next_pc_raw (current_frame, current_pc, FALSE);
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if (memaddr == gdbarch_addr_bits_remove (gdbarch, next_pc))
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return IS_THUMB_ADDR (next_pc);
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else
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return is_thumb;
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}
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}
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/* Otherwise we're out of luck; we assume ARM. */
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return 0;
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}
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/* Remove useless bits from addresses in a running program. */
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static CORE_ADDR
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arm_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR val)
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{
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if (arm_apcs_32)
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return UNMAKE_THUMB_ADDR (val);
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else
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return (val & 0x03fffffc);
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}
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/* When reading symbols, we need to zap the low bit of the address,
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which may be set to 1 for Thumb functions. */
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static CORE_ADDR
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arm_smash_text_address (struct gdbarch *gdbarch, CORE_ADDR val)
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{
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return val & ~1;
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}
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/* Analyze a Thumb prologue, looking for a recognizable stack frame
|
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and frame pointer. Scan until we encounter a store that could
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clobber the stack frame unexpectedly, or an unknown instruction. */
|
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static CORE_ADDR
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thumb_analyze_prologue (struct gdbarch *gdbarch,
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CORE_ADDR start, CORE_ADDR limit,
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struct arm_prologue_cache *cache)
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{
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enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
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int i;
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pv_t regs[16];
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struct pv_area *stack;
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struct cleanup *back_to;
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CORE_ADDR offset;
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for (i = 0; i < 16; i++)
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regs[i] = pv_register (i, 0);
|
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stack = make_pv_area (ARM_SP_REGNUM, gdbarch_addr_bit (gdbarch));
|
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back_to = make_cleanup_free_pv_area (stack);
|
||
|
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while (start < limit)
|
||
{
|
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unsigned short insn;
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insn = read_memory_unsigned_integer (start, 2, byte_order_for_code);
|
||
|
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if ((insn & 0xfe00) == 0xb400) /* push { rlist } */
|
||
{
|
||
int regno;
|
||
int mask;
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||
|
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if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
|
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break;
|
||
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/* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says
|
||
whether to save LR (R14). */
|
||
mask = (insn & 0xff) | ((insn & 0x100) << 6);
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||
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||
/* Calculate offsets of saved R0-R7 and LR. */
|
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for (regno = ARM_LR_REGNUM; regno >= 0; regno--)
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if (mask & (1 << regno))
|
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{
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||
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
|
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-4);
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pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[regno]);
|
||
}
|
||
}
|
||
else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR
|
||
sub sp, #simm */
|
||
{
|
||
offset = (insn & 0x7f) << 2; /* get scaled offset */
|
||
if (insn & 0x80) /* Check for SUB. */
|
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regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
|
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-offset);
|
||
else
|
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regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
|
||
offset);
|
||
}
|
||
else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
|
||
regs[THUMB_FP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
|
||
(insn & 0xff) << 2);
|
||
else if ((insn & 0xff00) == 0x4600) /* mov hi, lo or mov lo, hi */
|
||
{
|
||
int dst_reg = (insn & 0x7) + ((insn & 0x80) >> 4);
|
||
int src_reg = (insn & 0x78) >> 3;
|
||
regs[dst_reg] = regs[src_reg];
|
||
}
|
||
else if ((insn & 0xf800) == 0x9000) /* str rd, [sp, #off] */
|
||
{
|
||
/* Handle stores to the stack. Normally pushes are used,
|
||
but with GCC -mtpcs-frame, there may be other stores
|
||
in the prologue to create the frame. */
|
||
int regno = (insn >> 8) & 0x7;
|
||
pv_t addr;
|
||
|
||
offset = (insn & 0xff) << 2;
|
||
addr = pv_add_constant (regs[ARM_SP_REGNUM], offset);
|
||
|
||
if (pv_area_store_would_trash (stack, addr))
|
||
break;
|
||
|
||
pv_area_store (stack, addr, 4, regs[regno]);
|
||
}
|
||
else
|
||
{
|
||
/* We don't know what this instruction is. We're finished
|
||
scanning. NOTE: Recognizing more safe-to-ignore
|
||
instructions here will improve support for optimized
|
||
code. */
|
||
break;
|
||
}
|
||
|
||
start += 2;
|
||
}
|
||
|
||
if (cache == NULL)
|
||
{
|
||
do_cleanups (back_to);
|
||
return start;
|
||
}
|
||
|
||
if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
|
||
{
|
||
/* Frame pointer is fp. Frame size is constant. */
|
||
cache->framereg = ARM_FP_REGNUM;
|
||
cache->framesize = -regs[ARM_FP_REGNUM].k;
|
||
}
|
||
else if (pv_is_register (regs[THUMB_FP_REGNUM], ARM_SP_REGNUM))
|
||
{
|
||
/* Frame pointer is r7. Frame size is constant. */
|
||
cache->framereg = THUMB_FP_REGNUM;
|
||
cache->framesize = -regs[THUMB_FP_REGNUM].k;
|
||
}
|
||
else if (pv_is_register (regs[ARM_SP_REGNUM], ARM_SP_REGNUM))
|
||
{
|
||
/* Try the stack pointer... this is a bit desperate. */
|
||
cache->framereg = ARM_SP_REGNUM;
|
||
cache->framesize = -regs[ARM_SP_REGNUM].k;
|
||
}
|
||
else
|
||
{
|
||
/* We're just out of luck. We don't know where the frame is. */
|
||
cache->framereg = -1;
|
||
cache->framesize = 0;
|
||
}
|
||
|
||
for (i = 0; i < 16; i++)
|
||
if (pv_area_find_reg (stack, gdbarch, i, &offset))
|
||
cache->saved_regs[i].addr = offset;
|
||
|
||
do_cleanups (back_to);
|
||
return start;
|
||
}
|
||
|
||
/* Advance the PC across any function entry prologue instructions to
|
||
reach some "real" code.
|
||
|
||
The APCS (ARM Procedure Call Standard) defines the following
|
||
prologue:
|
||
|
||
mov ip, sp
|
||
[stmfd sp!, {a1,a2,a3,a4}]
|
||
stmfd sp!, {...,fp,ip,lr,pc}
|
||
[stfe f7, [sp, #-12]!]
|
||
[stfe f6, [sp, #-12]!]
|
||
[stfe f5, [sp, #-12]!]
|
||
[stfe f4, [sp, #-12]!]
|
||
sub fp, ip, #nn @@ nn == 20 or 4 depending on second insn */
|
||
|
||
static CORE_ADDR
|
||
arm_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
|
||
{
|
||
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
|
||
unsigned long inst;
|
||
CORE_ADDR skip_pc;
|
||
CORE_ADDR func_addr, limit_pc;
|
||
struct symtab_and_line sal;
|
||
|
||
/* If we're in a dummy frame, don't even try to skip the prologue. */
|
||
if (deprecated_pc_in_call_dummy (gdbarch, pc))
|
||
return pc;
|
||
|
||
/* See if we can determine the end of the prologue via the symbol table.
|
||
If so, then return either PC, or the PC after the prologue, whichever
|
||
is greater. */
|
||
if (find_pc_partial_function (pc, NULL, &func_addr, NULL))
|
||
{
|
||
CORE_ADDR post_prologue_pc
|
||
= skip_prologue_using_sal (gdbarch, func_addr);
|
||
if (post_prologue_pc != 0)
|
||
return max (pc, post_prologue_pc);
|
||
}
|
||
|
||
/* Can't determine prologue from the symbol table, need to examine
|
||
instructions. */
|
||
|
||
/* Find an upper limit on the function prologue using the debug
|
||
information. If the debug information could not be used to provide
|
||
that bound, then use an arbitrary large number as the upper bound. */
|
||
/* Like arm_scan_prologue, stop no later than pc + 64. */
|
||
limit_pc = skip_prologue_using_sal (gdbarch, pc);
|
||
if (limit_pc == 0)
|
||
limit_pc = pc + 64; /* Magic. */
|
||
|
||
|
||
/* Check if this is Thumb code. */
|
||
if (arm_pc_is_thumb (pc))
|
||
return thumb_analyze_prologue (gdbarch, pc, limit_pc, NULL);
|
||
|
||
for (skip_pc = pc; skip_pc < limit_pc; skip_pc += 4)
|
||
{
|
||
inst = read_memory_unsigned_integer (skip_pc, 4, byte_order_for_code);
|
||
|
||
/* "mov ip, sp" is no longer a required part of the prologue. */
|
||
if (inst == 0xe1a0c00d) /* mov ip, sp */
|
||
continue;
|
||
|
||
if ((inst & 0xfffff000) == 0xe28dc000) /* add ip, sp #n */
|
||
continue;
|
||
|
||
if ((inst & 0xfffff000) == 0xe24dc000) /* sub ip, sp #n */
|
||
continue;
|
||
|
||
/* Some prologues begin with "str lr, [sp, #-4]!". */
|
||
if (inst == 0xe52de004) /* str lr, [sp, #-4]! */
|
||
continue;
|
||
|
||
if ((inst & 0xfffffff0) == 0xe92d0000) /* stmfd sp!,{a1,a2,a3,a4} */
|
||
continue;
|
||
|
||
if ((inst & 0xfffff800) == 0xe92dd800) /* stmfd sp!,{fp,ip,lr,pc} */
|
||
continue;
|
||
|
||
/* Any insns after this point may float into the code, if it makes
|
||
for better instruction scheduling, so we skip them only if we
|
||
find them, but still consider the function to be frame-ful. */
|
||
|
||
/* We may have either one sfmfd instruction here, or several stfe
|
||
insns, depending on the version of floating point code we
|
||
support. */
|
||
if ((inst & 0xffbf0fff) == 0xec2d0200) /* sfmfd fn, <cnt>, [sp]! */
|
||
continue;
|
||
|
||
if ((inst & 0xffff8fff) == 0xed6d0103) /* stfe fn, [sp, #-12]! */
|
||
continue;
|
||
|
||
if ((inst & 0xfffff000) == 0xe24cb000) /* sub fp, ip, #nn */
|
||
continue;
|
||
|
||
if ((inst & 0xfffff000) == 0xe24dd000) /* sub sp, sp, #nn */
|
||
continue;
|
||
|
||
if ((inst & 0xffffc000) == 0xe54b0000 /* strb r(0123),[r11,#-nn] */
|
||
|| (inst & 0xffffc0f0) == 0xe14b00b0 /* strh r(0123),[r11,#-nn] */
|
||
|| (inst & 0xffffc000) == 0xe50b0000) /* str r(0123),[r11,#-nn] */
|
||
continue;
|
||
|
||
if ((inst & 0xffffc000) == 0xe5cd0000 /* strb r(0123),[sp,#nn] */
|
||
|| (inst & 0xffffc0f0) == 0xe1cd00b0 /* strh r(0123),[sp,#nn] */
|
||
|| (inst & 0xffffc000) == 0xe58d0000) /* str r(0123),[sp,#nn] */
|
||
continue;
|
||
|
||
/* Un-recognized instruction; stop scanning. */
|
||
break;
|
||
}
|
||
|
||
return skip_pc; /* End of prologue */
|
||
}
|
||
|
||
/* *INDENT-OFF* */
|
||
/* Function: thumb_scan_prologue (helper function for arm_scan_prologue)
|
||
This function decodes a Thumb function prologue to determine:
|
||
1) the size of the stack frame
|
||
2) which registers are saved on it
|
||
3) the offsets of saved regs
|
||
4) the offset from the stack pointer to the frame pointer
|
||
|
||
A typical Thumb function prologue would create this stack frame
|
||
(offsets relative to FP)
|
||
old SP -> 24 stack parameters
|
||
20 LR
|
||
16 R7
|
||
R7 -> 0 local variables (16 bytes)
|
||
SP -> -12 additional stack space (12 bytes)
|
||
The frame size would thus be 36 bytes, and the frame offset would be
|
||
12 bytes. The frame register is R7.
|
||
|
||
The comments for thumb_skip_prolog() describe the algorithm we use
|
||
to detect the end of the prolog. */
|
||
/* *INDENT-ON* */
|
||
|
||
static void
|
||
thumb_scan_prologue (struct gdbarch *gdbarch, CORE_ADDR prev_pc,
|
||
CORE_ADDR block_addr, struct arm_prologue_cache *cache)
|
||
{
|
||
CORE_ADDR prologue_start;
|
||
CORE_ADDR prologue_end;
|
||
CORE_ADDR current_pc;
|
||
|
||
if (find_pc_partial_function (block_addr, NULL, &prologue_start,
|
||
&prologue_end))
|
||
{
|
||
struct symtab_and_line sal = find_pc_line (prologue_start, 0);
|
||
|
||
if (sal.line == 0) /* no line info, use current PC */
|
||
prologue_end = prev_pc;
|
||
else if (sal.end < prologue_end) /* next line begins after fn end */
|
||
prologue_end = sal.end; /* (probably means no prologue) */
|
||
}
|
||
else
|
||
/* We're in the boondocks: we have no idea where the start of the
|
||
function is. */
|
||
return;
|
||
|
||
prologue_end = min (prologue_end, prev_pc);
|
||
|
||
thumb_analyze_prologue (gdbarch, prologue_start, prologue_end, cache);
|
||
}
|
||
|
||
/* This function decodes an ARM function prologue to determine:
|
||
1) the size of the stack frame
|
||
2) which registers are saved on it
|
||
3) the offsets of saved regs
|
||
4) the offset from the stack pointer to the frame pointer
|
||
This information is stored in the "extra" fields of the frame_info.
|
||
|
||
There are two basic forms for the ARM prologue. The fixed argument
|
||
function call will look like:
|
||
|
||
mov ip, sp
|
||
stmfd sp!, {fp, ip, lr, pc}
|
||
sub fp, ip, #4
|
||
[sub sp, sp, #4]
|
||
|
||
Which would create this stack frame (offsets relative to FP):
|
||
IP -> 4 (caller's stack)
|
||
FP -> 0 PC (points to address of stmfd instruction + 8 in callee)
|
||
-4 LR (return address in caller)
|
||
-8 IP (copy of caller's SP)
|
||
-12 FP (caller's FP)
|
||
SP -> -28 Local variables
|
||
|
||
The frame size would thus be 32 bytes, and the frame offset would be
|
||
28 bytes. The stmfd call can also save any of the vN registers it
|
||
plans to use, which increases the frame size accordingly.
|
||
|
||
Note: The stored PC is 8 off of the STMFD instruction that stored it
|
||
because the ARM Store instructions always store PC + 8 when you read
|
||
the PC register.
|
||
|
||
A variable argument function call will look like:
|
||
|
||
mov ip, sp
|
||
stmfd sp!, {a1, a2, a3, a4}
|
||
stmfd sp!, {fp, ip, lr, pc}
|
||
sub fp, ip, #20
|
||
|
||
Which would create this stack frame (offsets relative to FP):
|
||
IP -> 20 (caller's stack)
|
||
16 A4
|
||
12 A3
|
||
8 A2
|
||
4 A1
|
||
FP -> 0 PC (points to address of stmfd instruction + 8 in callee)
|
||
-4 LR (return address in caller)
|
||
-8 IP (copy of caller's SP)
|
||
-12 FP (caller's FP)
|
||
SP -> -28 Local variables
|
||
|
||
The frame size would thus be 48 bytes, and the frame offset would be
|
||
28 bytes.
|
||
|
||
There is another potential complication, which is that the optimizer
|
||
will try to separate the store of fp in the "stmfd" instruction from
|
||
the "sub fp, ip, #NN" instruction. Almost anything can be there, so
|
||
we just key on the stmfd, and then scan for the "sub fp, ip, #NN"...
|
||
|
||
Also, note, the original version of the ARM toolchain claimed that there
|
||
should be an
|
||
|
||
instruction at the end of the prologue. I have never seen GCC produce
|
||
this, and the ARM docs don't mention it. We still test for it below in
|
||
case it happens...
|
||
|
||
*/
|
||
|
||
static void
|
||
arm_scan_prologue (struct frame_info *this_frame,
|
||
struct arm_prologue_cache *cache)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (this_frame);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
|
||
int regno;
|
||
CORE_ADDR prologue_start, prologue_end, current_pc;
|
||
CORE_ADDR prev_pc = get_frame_pc (this_frame);
|
||
CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
|
||
pv_t regs[ARM_FPS_REGNUM];
|
||
struct pv_area *stack;
|
||
struct cleanup *back_to;
|
||
CORE_ADDR offset;
|
||
|
||
/* Assume there is no frame until proven otherwise. */
|
||
cache->framereg = ARM_SP_REGNUM;
|
||
cache->framesize = 0;
|
||
|
||
/* Check for Thumb prologue. */
|
||
if (arm_frame_is_thumb (this_frame))
|
||
{
|
||
thumb_scan_prologue (gdbarch, prev_pc, block_addr, cache);
|
||
return;
|
||
}
|
||
|
||
/* Find the function prologue. If we can't find the function in
|
||
the symbol table, peek in the stack frame to find the PC. */
|
||
if (find_pc_partial_function (block_addr, NULL, &prologue_start,
|
||
&prologue_end))
|
||
{
|
||
/* One way to find the end of the prologue (which works well
|
||
for unoptimized code) is to do the following:
|
||
|
||
struct symtab_and_line sal = find_pc_line (prologue_start, 0);
|
||
|
||
if (sal.line == 0)
|
||
prologue_end = prev_pc;
|
||
else if (sal.end < prologue_end)
|
||
prologue_end = sal.end;
|
||
|
||
This mechanism is very accurate so long as the optimizer
|
||
doesn't move any instructions from the function body into the
|
||
prologue. If this happens, sal.end will be the last
|
||
instruction in the first hunk of prologue code just before
|
||
the first instruction that the scheduler has moved from
|
||
the body to the prologue.
|
||
|
||
In order to make sure that we scan all of the prologue
|
||
instructions, we use a slightly less accurate mechanism which
|
||
may scan more than necessary. To help compensate for this
|
||
lack of accuracy, the prologue scanning loop below contains
|
||
several clauses which'll cause the loop to terminate early if
|
||
an implausible prologue instruction is encountered.
|
||
|
||
The expression
|
||
|
||
prologue_start + 64
|
||
|
||
is a suitable endpoint since it accounts for the largest
|
||
possible prologue plus up to five instructions inserted by
|
||
the scheduler. */
|
||
|
||
if (prologue_end > prologue_start + 64)
|
||
{
|
||
prologue_end = prologue_start + 64; /* See above. */
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* We have no symbol information. Our only option is to assume this
|
||
function has a standard stack frame and the normal frame register.
|
||
Then, we can find the value of our frame pointer on entrance to
|
||
the callee (or at the present moment if this is the innermost frame).
|
||
The value stored there should be the address of the stmfd + 8. */
|
||
CORE_ADDR frame_loc;
|
||
LONGEST return_value;
|
||
|
||
frame_loc = get_frame_register_unsigned (this_frame, ARM_FP_REGNUM);
|
||
if (!safe_read_memory_integer (frame_loc, 4, byte_order, &return_value))
|
||
return;
|
||
else
|
||
{
|
||
prologue_start = gdbarch_addr_bits_remove
|
||
(gdbarch, return_value) - 8;
|
||
prologue_end = prologue_start + 64; /* See above. */
|
||
}
|
||
}
|
||
|
||
if (prev_pc < prologue_end)
|
||
prologue_end = prev_pc;
|
||
|
||
/* Now search the prologue looking for instructions that set up the
|
||
frame pointer, adjust the stack pointer, and save registers.
|
||
|
||
Be careful, however, and if it doesn't look like a prologue,
|
||
don't try to scan it. If, for instance, a frameless function
|
||
begins with stmfd sp!, then we will tell ourselves there is
|
||
a frame, which will confuse stack traceback, as well as "finish"
|
||
and other operations that rely on a knowledge of the stack
|
||
traceback.
|
||
|
||
In the APCS, the prologue should start with "mov ip, sp" so
|
||
if we don't see this as the first insn, we will stop.
|
||
|
||
[Note: This doesn't seem to be true any longer, so it's now an
|
||
optional part of the prologue. - Kevin Buettner, 2001-11-20]
|
||
|
||
[Note further: The "mov ip,sp" only seems to be missing in
|
||
frameless functions at optimization level "-O2" or above,
|
||
in which case it is often (but not always) replaced by
|
||
"str lr, [sp, #-4]!". - Michael Snyder, 2002-04-23] */
|
||
|
||
for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
|
||
regs[regno] = pv_register (regno, 0);
|
||
stack = make_pv_area (ARM_SP_REGNUM, gdbarch_addr_bit (gdbarch));
|
||
back_to = make_cleanup_free_pv_area (stack);
|
||
|
||
for (current_pc = prologue_start;
|
||
current_pc < prologue_end;
|
||
current_pc += 4)
|
||
{
|
||
unsigned int insn
|
||
= read_memory_unsigned_integer (current_pc, 4, byte_order_for_code);
|
||
|
||
if (insn == 0xe1a0c00d) /* mov ip, sp */
|
||
{
|
||
regs[ARM_IP_REGNUM] = regs[ARM_SP_REGNUM];
|
||
continue;
|
||
}
|
||
else if ((insn & 0xfffff000) == 0xe28dc000) /* add ip, sp #n */
|
||
{
|
||
unsigned imm = insn & 0xff; /* immediate value */
|
||
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
|
||
imm = (imm >> rot) | (imm << (32 - rot));
|
||
regs[ARM_IP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], imm);
|
||
continue;
|
||
}
|
||
else if ((insn & 0xfffff000) == 0xe24dc000) /* sub ip, sp #n */
|
||
{
|
||
unsigned imm = insn & 0xff; /* immediate value */
|
||
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
|
||
imm = (imm >> rot) | (imm << (32 - rot));
|
||
regs[ARM_IP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
|
||
continue;
|
||
}
|
||
else if (insn == 0xe52de004) /* str lr, [sp, #-4]! */
|
||
{
|
||
if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
|
||
break;
|
||
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4);
|
||
pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[ARM_LR_REGNUM]);
|
||
continue;
|
||
}
|
||
else if ((insn & 0xffff0000) == 0xe92d0000)
|
||
/* stmfd sp!, {..., fp, ip, lr, pc}
|
||
or
|
||
stmfd sp!, {a1, a2, a3, a4} */
|
||
{
|
||
int mask = insn & 0xffff;
|
||
|
||
if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
|
||
break;
|
||
|
||
/* Calculate offsets of saved registers. */
|
||
for (regno = ARM_PC_REGNUM; regno >= 0; regno--)
|
||
if (mask & (1 << regno))
|
||
{
|
||
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4);
|
||
pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[regno]);
|
||
}
|
||
}
|
||
else if ((insn & 0xffffc000) == 0xe54b0000 /* strb rx,[r11,#-n] */
|
||
|| (insn & 0xffffc0f0) == 0xe14b00b0 /* strh rx,[r11,#-n] */
|
||
|| (insn & 0xffffc000) == 0xe50b0000) /* str rx,[r11,#-n] */
|
||
{
|
||
/* No need to add this to saved_regs -- it's just an arg reg. */
|
||
continue;
|
||
}
|
||
else if ((insn & 0xffffc000) == 0xe5cd0000 /* strb rx,[sp,#n] */
|
||
|| (insn & 0xffffc0f0) == 0xe1cd00b0 /* strh rx,[sp,#n] */
|
||
|| (insn & 0xffffc000) == 0xe58d0000) /* str rx,[sp,#n] */
|
||
{
|
||
/* No need to add this to saved_regs -- it's just an arg reg. */
|
||
continue;
|
||
}
|
||
else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */
|
||
{
|
||
unsigned imm = insn & 0xff; /* immediate value */
|
||
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
|
||
imm = (imm >> rot) | (imm << (32 - rot));
|
||
regs[ARM_FP_REGNUM] = pv_add_constant (regs[ARM_IP_REGNUM], -imm);
|
||
}
|
||
else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */
|
||
{
|
||
unsigned imm = insn & 0xff; /* immediate value */
|
||
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
|
||
imm = (imm >> rot) | (imm << (32 - rot));
|
||
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
|
||
}
|
||
else if ((insn & 0xffff7fff) == 0xed6d0103 /* stfe f?, [sp, -#c]! */
|
||
&& gdbarch_tdep (gdbarch)->have_fpa_registers)
|
||
{
|
||
if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
|
||
break;
|
||
|
||
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12);
|
||
regno = ARM_F0_REGNUM + ((insn >> 12) & 0x07);
|
||
pv_area_store (stack, regs[ARM_SP_REGNUM], 12, regs[regno]);
|
||
}
|
||
else if ((insn & 0xffbf0fff) == 0xec2d0200 /* sfmfd f0, 4, [sp!] */
|
||
&& gdbarch_tdep (gdbarch)->have_fpa_registers)
|
||
{
|
||
int n_saved_fp_regs;
|
||
unsigned int fp_start_reg, fp_bound_reg;
|
||
|
||
if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
|
||
break;
|
||
|
||
if ((insn & 0x800) == 0x800) /* N0 is set */
|
||
{
|
||
if ((insn & 0x40000) == 0x40000) /* N1 is set */
|
||
n_saved_fp_regs = 3;
|
||
else
|
||
n_saved_fp_regs = 1;
|
||
}
|
||
else
|
||
{
|
||
if ((insn & 0x40000) == 0x40000) /* N1 is set */
|
||
n_saved_fp_regs = 2;
|
||
else
|
||
n_saved_fp_regs = 4;
|
||
}
|
||
|
||
fp_start_reg = ARM_F0_REGNUM + ((insn >> 12) & 0x7);
|
||
fp_bound_reg = fp_start_reg + n_saved_fp_regs;
|
||
for (; fp_start_reg < fp_bound_reg; fp_start_reg++)
|
||
{
|
||
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12);
|
||
pv_area_store (stack, regs[ARM_SP_REGNUM], 12,
|
||
regs[fp_start_reg++]);
|
||
}
|
||
}
|
||
else if ((insn & 0xf0000000) != 0xe0000000)
|
||
break; /* Condition not true, exit early */
|
||
else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */
|
||
break; /* Don't scan past a block load */
|
||
else
|
||
/* The optimizer might shove anything into the prologue,
|
||
so we just skip what we don't recognize. */
|
||
continue;
|
||
}
|
||
|
||
/* The frame size is just the distance from the frame register
|
||
to the original stack pointer. */
|
||
if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
|
||
{
|
||
/* Frame pointer is fp. */
|
||
cache->framereg = ARM_FP_REGNUM;
|
||
cache->framesize = -regs[ARM_FP_REGNUM].k;
|
||
}
|
||
else if (pv_is_register (regs[ARM_SP_REGNUM], ARM_SP_REGNUM))
|
||
{
|
||
/* Try the stack pointer... this is a bit desperate. */
|
||
cache->framereg = ARM_SP_REGNUM;
|
||
cache->framesize = -regs[ARM_SP_REGNUM].k;
|
||
}
|
||
else
|
||
{
|
||
/* We're just out of luck. We don't know where the frame is. */
|
||
cache->framereg = -1;
|
||
cache->framesize = 0;
|
||
}
|
||
|
||
for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
|
||
if (pv_area_find_reg (stack, gdbarch, regno, &offset))
|
||
cache->saved_regs[regno].addr = offset;
|
||
|
||
do_cleanups (back_to);
|
||
}
|
||
|
||
static struct arm_prologue_cache *
|
||
arm_make_prologue_cache (struct frame_info *this_frame)
|
||
{
|
||
int reg;
|
||
struct arm_prologue_cache *cache;
|
||
CORE_ADDR unwound_fp;
|
||
|
||
cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
|
||
cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
|
||
|
||
arm_scan_prologue (this_frame, cache);
|
||
|
||
unwound_fp = get_frame_register_unsigned (this_frame, cache->framereg);
|
||
if (unwound_fp == 0)
|
||
return cache;
|
||
|
||
cache->prev_sp = unwound_fp + cache->framesize;
|
||
|
||
/* Calculate actual addresses of saved registers using offsets
|
||
determined by arm_scan_prologue. */
|
||
for (reg = 0; reg < gdbarch_num_regs (get_frame_arch (this_frame)); reg++)
|
||
if (trad_frame_addr_p (cache->saved_regs, reg))
|
||
cache->saved_regs[reg].addr += cache->prev_sp;
|
||
|
||
return cache;
|
||
}
|
||
|
||
/* Our frame ID for a normal frame is the current function's starting PC
|
||
and the caller's SP when we were called. */
|
||
|
||
static void
|
||
arm_prologue_this_id (struct frame_info *this_frame,
|
||
void **this_cache,
|
||
struct frame_id *this_id)
|
||
{
|
||
struct arm_prologue_cache *cache;
|
||
struct frame_id id;
|
||
CORE_ADDR pc, func;
|
||
|
||
if (*this_cache == NULL)
|
||
*this_cache = arm_make_prologue_cache (this_frame);
|
||
cache = *this_cache;
|
||
|
||
/* This is meant to halt the backtrace at "_start". */
|
||
pc = get_frame_pc (this_frame);
|
||
if (pc <= gdbarch_tdep (get_frame_arch (this_frame))->lowest_pc)
|
||
return;
|
||
|
||
/* If we've hit a wall, stop. */
|
||
if (cache->prev_sp == 0)
|
||
return;
|
||
|
||
func = get_frame_func (this_frame);
|
||
id = frame_id_build (cache->prev_sp, func);
|
||
*this_id = id;
|
||
}
|
||
|
||
static struct value *
|
||
arm_prologue_prev_register (struct frame_info *this_frame,
|
||
void **this_cache,
|
||
int prev_regnum)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (this_frame);
|
||
struct arm_prologue_cache *cache;
|
||
|
||
if (*this_cache == NULL)
|
||
*this_cache = arm_make_prologue_cache (this_frame);
|
||
cache = *this_cache;
|
||
|
||
/* If we are asked to unwind the PC, then we need to return the LR
|
||
instead. The prologue may save PC, but it will point into this
|
||
frame's prologue, not the next frame's resume location. Also
|
||
strip the saved T bit. A valid LR may have the low bit set, but
|
||
a valid PC never does. */
|
||
if (prev_regnum == ARM_PC_REGNUM)
|
||
{
|
||
CORE_ADDR lr;
|
||
|
||
lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
|
||
return frame_unwind_got_constant (this_frame, prev_regnum,
|
||
arm_addr_bits_remove (gdbarch, lr));
|
||
}
|
||
|
||
/* SP is generally not saved to the stack, but this frame is
|
||
identified by the next frame's stack pointer at the time of the call.
|
||
The value was already reconstructed into PREV_SP. */
|
||
if (prev_regnum == ARM_SP_REGNUM)
|
||
return frame_unwind_got_constant (this_frame, prev_regnum, cache->prev_sp);
|
||
|
||
/* The CPSR may have been changed by the call instruction and by the
|
||
called function. The only bit we can reconstruct is the T bit,
|
||
by checking the low bit of LR as of the call. This is a reliable
|
||
indicator of Thumb-ness except for some ARM v4T pre-interworking
|
||
Thumb code, which could get away with a clear low bit as long as
|
||
the called function did not use bx. Guess that all other
|
||
bits are unchanged; the condition flags are presumably lost,
|
||
but the processor status is likely valid. */
|
||
if (prev_regnum == ARM_PS_REGNUM)
|
||
{
|
||
CORE_ADDR lr, cpsr;
|
||
|
||
cpsr = get_frame_register_unsigned (this_frame, prev_regnum);
|
||
lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
|
||
if (IS_THUMB_ADDR (lr))
|
||
cpsr |= CPSR_T;
|
||
else
|
||
cpsr &= ~CPSR_T;
|
||
return frame_unwind_got_constant (this_frame, prev_regnum, cpsr);
|
||
}
|
||
|
||
return trad_frame_get_prev_register (this_frame, cache->saved_regs,
|
||
prev_regnum);
|
||
}
|
||
|
||
struct frame_unwind arm_prologue_unwind = {
|
||
NORMAL_FRAME,
|
||
arm_prologue_this_id,
|
||
arm_prologue_prev_register,
|
||
NULL,
|
||
default_frame_sniffer
|
||
};
|
||
|
||
static struct arm_prologue_cache *
|
||
arm_make_stub_cache (struct frame_info *this_frame)
|
||
{
|
||
struct arm_prologue_cache *cache;
|
||
|
||
cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
|
||
cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
|
||
|
||
cache->prev_sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
|
||
|
||
return cache;
|
||
}
|
||
|
||
/* Our frame ID for a stub frame is the current SP and LR. */
|
||
|
||
static void
|
||
arm_stub_this_id (struct frame_info *this_frame,
|
||
void **this_cache,
|
||
struct frame_id *this_id)
|
||
{
|
||
struct arm_prologue_cache *cache;
|
||
|
||
if (*this_cache == NULL)
|
||
*this_cache = arm_make_stub_cache (this_frame);
|
||
cache = *this_cache;
|
||
|
||
*this_id = frame_id_build (cache->prev_sp, get_frame_pc (this_frame));
|
||
}
|
||
|
||
static int
|
||
arm_stub_unwind_sniffer (const struct frame_unwind *self,
|
||
struct frame_info *this_frame,
|
||
void **this_prologue_cache)
|
||
{
|
||
CORE_ADDR addr_in_block;
|
||
char dummy[4];
|
||
|
||
addr_in_block = get_frame_address_in_block (this_frame);
|
||
if (in_plt_section (addr_in_block, NULL)
|
||
/* We also use the stub winder if the target memory is unreadable
|
||
to avoid having the prologue unwinder trying to read it. */
|
||
|| target_read_memory (get_frame_pc (this_frame), dummy, 4) != 0)
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
struct frame_unwind arm_stub_unwind = {
|
||
NORMAL_FRAME,
|
||
arm_stub_this_id,
|
||
arm_prologue_prev_register,
|
||
NULL,
|
||
arm_stub_unwind_sniffer
|
||
};
|
||
|
||
static CORE_ADDR
|
||
arm_normal_frame_base (struct frame_info *this_frame, void **this_cache)
|
||
{
|
||
struct arm_prologue_cache *cache;
|
||
|
||
if (*this_cache == NULL)
|
||
*this_cache = arm_make_prologue_cache (this_frame);
|
||
cache = *this_cache;
|
||
|
||
return cache->prev_sp - cache->framesize;
|
||
}
|
||
|
||
struct frame_base arm_normal_base = {
|
||
&arm_prologue_unwind,
|
||
arm_normal_frame_base,
|
||
arm_normal_frame_base,
|
||
arm_normal_frame_base
|
||
};
|
||
|
||
/* Assuming THIS_FRAME is a dummy, return the frame ID of that
|
||
dummy frame. The frame ID's base needs to match the TOS value
|
||
saved by save_dummy_frame_tos() and returned from
|
||
arm_push_dummy_call, and the PC needs to match the dummy frame's
|
||
breakpoint. */
|
||
|
||
static struct frame_id
|
||
arm_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
|
||
{
|
||
return frame_id_build (get_frame_register_unsigned (this_frame, ARM_SP_REGNUM),
|
||
get_frame_pc (this_frame));
|
||
}
|
||
|
||
/* Given THIS_FRAME, find the previous frame's resume PC (which will
|
||
be used to construct the previous frame's ID, after looking up the
|
||
containing function). */
|
||
|
||
static CORE_ADDR
|
||
arm_unwind_pc (struct gdbarch *gdbarch, struct frame_info *this_frame)
|
||
{
|
||
CORE_ADDR pc;
|
||
pc = frame_unwind_register_unsigned (this_frame, ARM_PC_REGNUM);
|
||
return arm_addr_bits_remove (gdbarch, pc);
|
||
}
|
||
|
||
static CORE_ADDR
|
||
arm_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
|
||
{
|
||
return frame_unwind_register_unsigned (this_frame, ARM_SP_REGNUM);
|
||
}
|
||
|
||
static struct value *
|
||
arm_dwarf2_prev_register (struct frame_info *this_frame, void **this_cache,
|
||
int regnum)
|
||
{
|
||
struct gdbarch * gdbarch = get_frame_arch (this_frame);
|
||
CORE_ADDR lr, cpsr;
|
||
|
||
switch (regnum)
|
||
{
|
||
case ARM_PC_REGNUM:
|
||
/* The PC is normally copied from the return column, which
|
||
describes saves of LR. However, that version may have an
|
||
extra bit set to indicate Thumb state. The bit is not
|
||
part of the PC. */
|
||
lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
|
||
return frame_unwind_got_constant (this_frame, regnum,
|
||
arm_addr_bits_remove (gdbarch, lr));
|
||
|
||
case ARM_PS_REGNUM:
|
||
/* Reconstruct the T bit; see arm_prologue_prev_register for details. */
|
||
cpsr = get_frame_register_unsigned (this_frame, regnum);
|
||
lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
|
||
if (IS_THUMB_ADDR (lr))
|
||
cpsr |= CPSR_T;
|
||
else
|
||
cpsr &= ~CPSR_T;
|
||
return frame_unwind_got_constant (this_frame, regnum, cpsr);
|
||
|
||
default:
|
||
internal_error (__FILE__, __LINE__,
|
||
_("Unexpected register %d"), regnum);
|
||
}
|
||
}
|
||
|
||
static void
|
||
arm_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
|
||
struct dwarf2_frame_state_reg *reg,
|
||
struct frame_info *this_frame)
|
||
{
|
||
switch (regnum)
|
||
{
|
||
case ARM_PC_REGNUM:
|
||
case ARM_PS_REGNUM:
|
||
reg->how = DWARF2_FRAME_REG_FN;
|
||
reg->loc.fn = arm_dwarf2_prev_register;
|
||
break;
|
||
case ARM_SP_REGNUM:
|
||
reg->how = DWARF2_FRAME_REG_CFA;
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* When arguments must be pushed onto the stack, they go on in reverse
|
||
order. The code below implements a FILO (stack) to do this. */
|
||
|
||
struct stack_item
|
||
{
|
||
int len;
|
||
struct stack_item *prev;
|
||
void *data;
|
||
};
|
||
|
||
static struct stack_item *
|
||
push_stack_item (struct stack_item *prev, void *contents, int len)
|
||
{
|
||
struct stack_item *si;
|
||
si = xmalloc (sizeof (struct stack_item));
|
||
si->data = xmalloc (len);
|
||
si->len = len;
|
||
si->prev = prev;
|
||
memcpy (si->data, contents, len);
|
||
return si;
|
||
}
|
||
|
||
static struct stack_item *
|
||
pop_stack_item (struct stack_item *si)
|
||
{
|
||
struct stack_item *dead = si;
|
||
si = si->prev;
|
||
xfree (dead->data);
|
||
xfree (dead);
|
||
return si;
|
||
}
|
||
|
||
|
||
/* Return the alignment (in bytes) of the given type. */
|
||
|
||
static int
|
||
arm_type_align (struct type *t)
|
||
{
|
||
int n;
|
||
int align;
|
||
int falign;
|
||
|
||
t = check_typedef (t);
|
||
switch (TYPE_CODE (t))
|
||
{
|
||
default:
|
||
/* Should never happen. */
|
||
internal_error (__FILE__, __LINE__, _("unknown type alignment"));
|
||
return 4;
|
||
|
||
case TYPE_CODE_PTR:
|
||
case TYPE_CODE_ENUM:
|
||
case TYPE_CODE_INT:
|
||
case TYPE_CODE_FLT:
|
||
case TYPE_CODE_SET:
|
||
case TYPE_CODE_RANGE:
|
||
case TYPE_CODE_BITSTRING:
|
||
case TYPE_CODE_REF:
|
||
case TYPE_CODE_CHAR:
|
||
case TYPE_CODE_BOOL:
|
||
return TYPE_LENGTH (t);
|
||
|
||
case TYPE_CODE_ARRAY:
|
||
case TYPE_CODE_COMPLEX:
|
||
/* TODO: What about vector types? */
|
||
return arm_type_align (TYPE_TARGET_TYPE (t));
|
||
|
||
case TYPE_CODE_STRUCT:
|
||
case TYPE_CODE_UNION:
|
||
align = 1;
|
||
for (n = 0; n < TYPE_NFIELDS (t); n++)
|
||
{
|
||
falign = arm_type_align (TYPE_FIELD_TYPE (t, n));
|
||
if (falign > align)
|
||
align = falign;
|
||
}
|
||
return align;
|
||
}
|
||
}
|
||
|
||
/* Possible base types for a candidate for passing and returning in
|
||
VFP registers. */
|
||
|
||
enum arm_vfp_cprc_base_type
|
||
{
|
||
VFP_CPRC_UNKNOWN,
|
||
VFP_CPRC_SINGLE,
|
||
VFP_CPRC_DOUBLE,
|
||
VFP_CPRC_VEC64,
|
||
VFP_CPRC_VEC128
|
||
};
|
||
|
||
/* The length of one element of base type B. */
|
||
|
||
static unsigned
|
||
arm_vfp_cprc_unit_length (enum arm_vfp_cprc_base_type b)
|
||
{
|
||
switch (b)
|
||
{
|
||
case VFP_CPRC_SINGLE:
|
||
return 4;
|
||
case VFP_CPRC_DOUBLE:
|
||
return 8;
|
||
case VFP_CPRC_VEC64:
|
||
return 8;
|
||
case VFP_CPRC_VEC128:
|
||
return 16;
|
||
default:
|
||
internal_error (__FILE__, __LINE__, _("Invalid VFP CPRC type: %d."),
|
||
(int) b);
|
||
}
|
||
}
|
||
|
||
/* The character ('s', 'd' or 'q') for the type of VFP register used
|
||
for passing base type B. */
|
||
|
||
static int
|
||
arm_vfp_cprc_reg_char (enum arm_vfp_cprc_base_type b)
|
||
{
|
||
switch (b)
|
||
{
|
||
case VFP_CPRC_SINGLE:
|
||
return 's';
|
||
case VFP_CPRC_DOUBLE:
|
||
return 'd';
|
||
case VFP_CPRC_VEC64:
|
||
return 'd';
|
||
case VFP_CPRC_VEC128:
|
||
return 'q';
|
||
default:
|
||
internal_error (__FILE__, __LINE__, _("Invalid VFP CPRC type: %d."),
|
||
(int) b);
|
||
}
|
||
}
|
||
|
||
/* Determine whether T may be part of a candidate for passing and
|
||
returning in VFP registers, ignoring the limit on the total number
|
||
of components. If *BASE_TYPE is VFP_CPRC_UNKNOWN, set it to the
|
||
classification of the first valid component found; if it is not
|
||
VFP_CPRC_UNKNOWN, all components must have the same classification
|
||
as *BASE_TYPE. If it is found that T contains a type not permitted
|
||
for passing and returning in VFP registers, a type differently
|
||
classified from *BASE_TYPE, or two types differently classified
|
||
from each other, return -1, otherwise return the total number of
|
||
base-type elements found (possibly 0 in an empty structure or
|
||
array). Vectors and complex types are not currently supported,
|
||
matching the generic AAPCS support. */
|
||
|
||
static int
|
||
arm_vfp_cprc_sub_candidate (struct type *t,
|
||
enum arm_vfp_cprc_base_type *base_type)
|
||
{
|
||
t = check_typedef (t);
|
||
switch (TYPE_CODE (t))
|
||
{
|
||
case TYPE_CODE_FLT:
|
||
switch (TYPE_LENGTH (t))
|
||
{
|
||
case 4:
|
||
if (*base_type == VFP_CPRC_UNKNOWN)
|
||
*base_type = VFP_CPRC_SINGLE;
|
||
else if (*base_type != VFP_CPRC_SINGLE)
|
||
return -1;
|
||
return 1;
|
||
|
||
case 8:
|
||
if (*base_type == VFP_CPRC_UNKNOWN)
|
||
*base_type = VFP_CPRC_DOUBLE;
|
||
else if (*base_type != VFP_CPRC_DOUBLE)
|
||
return -1;
|
||
return 1;
|
||
|
||
default:
|
||
return -1;
|
||
}
|
||
break;
|
||
|
||
case TYPE_CODE_ARRAY:
|
||
{
|
||
int count;
|
||
unsigned unitlen;
|
||
count = arm_vfp_cprc_sub_candidate (TYPE_TARGET_TYPE (t), base_type);
|
||
if (count == -1)
|
||
return -1;
|
||
if (TYPE_LENGTH (t) == 0)
|
||
{
|
||
gdb_assert (count == 0);
|
||
return 0;
|
||
}
|
||
else if (count == 0)
|
||
return -1;
|
||
unitlen = arm_vfp_cprc_unit_length (*base_type);
|
||
gdb_assert ((TYPE_LENGTH (t) % unitlen) == 0);
|
||
return TYPE_LENGTH (t) / unitlen;
|
||
}
|
||
break;
|
||
|
||
case TYPE_CODE_STRUCT:
|
||
{
|
||
int count = 0;
|
||
unsigned unitlen;
|
||
int i;
|
||
for (i = 0; i < TYPE_NFIELDS (t); i++)
|
||
{
|
||
int sub_count = arm_vfp_cprc_sub_candidate (TYPE_FIELD_TYPE (t, i),
|
||
base_type);
|
||
if (sub_count == -1)
|
||
return -1;
|
||
count += sub_count;
|
||
}
|
||
if (TYPE_LENGTH (t) == 0)
|
||
{
|
||
gdb_assert (count == 0);
|
||
return 0;
|
||
}
|
||
else if (count == 0)
|
||
return -1;
|
||
unitlen = arm_vfp_cprc_unit_length (*base_type);
|
||
if (TYPE_LENGTH (t) != unitlen * count)
|
||
return -1;
|
||
return count;
|
||
}
|
||
|
||
case TYPE_CODE_UNION:
|
||
{
|
||
int count = 0;
|
||
unsigned unitlen;
|
||
int i;
|
||
for (i = 0; i < TYPE_NFIELDS (t); i++)
|
||
{
|
||
int sub_count = arm_vfp_cprc_sub_candidate (TYPE_FIELD_TYPE (t, i),
|
||
base_type);
|
||
if (sub_count == -1)
|
||
return -1;
|
||
count = (count > sub_count ? count : sub_count);
|
||
}
|
||
if (TYPE_LENGTH (t) == 0)
|
||
{
|
||
gdb_assert (count == 0);
|
||
return 0;
|
||
}
|
||
else if (count == 0)
|
||
return -1;
|
||
unitlen = arm_vfp_cprc_unit_length (*base_type);
|
||
if (TYPE_LENGTH (t) != unitlen * count)
|
||
return -1;
|
||
return count;
|
||
}
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
return -1;
|
||
}
|
||
|
||
/* Determine whether T is a VFP co-processor register candidate (CPRC)
|
||
if passed to or returned from a non-variadic function with the VFP
|
||
ABI in effect. Return 1 if it is, 0 otherwise. If it is, set
|
||
*BASE_TYPE to the base type for T and *COUNT to the number of
|
||
elements of that base type before returning. */
|
||
|
||
static int
|
||
arm_vfp_call_candidate (struct type *t, enum arm_vfp_cprc_base_type *base_type,
|
||
int *count)
|
||
{
|
||
enum arm_vfp_cprc_base_type b = VFP_CPRC_UNKNOWN;
|
||
int c = arm_vfp_cprc_sub_candidate (t, &b);
|
||
if (c <= 0 || c > 4)
|
||
return 0;
|
||
*base_type = b;
|
||
*count = c;
|
||
return 1;
|
||
}
|
||
|
||
/* Return 1 if the VFP ABI should be used for passing arguments to and
|
||
returning values from a function of type FUNC_TYPE, 0
|
||
otherwise. */
|
||
|
||
static int
|
||
arm_vfp_abi_for_function (struct gdbarch *gdbarch, struct type *func_type)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
/* Variadic functions always use the base ABI. Assume that functions
|
||
without debug info are not variadic. */
|
||
if (func_type && TYPE_VARARGS (check_typedef (func_type)))
|
||
return 0;
|
||
/* The VFP ABI is only supported as a variant of AAPCS. */
|
||
if (tdep->arm_abi != ARM_ABI_AAPCS)
|
||
return 0;
|
||
return gdbarch_tdep (gdbarch)->fp_model == ARM_FLOAT_VFP;
|
||
}
|
||
|
||
/* We currently only support passing parameters in integer registers, which
|
||
conforms with GCC's default model, and VFP argument passing following
|
||
the VFP variant of AAPCS. Several other variants exist and
|
||
we should probably support some of them based on the selected ABI. */
|
||
|
||
static CORE_ADDR
|
||
arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
|
||
struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
|
||
struct value **args, CORE_ADDR sp, int struct_return,
|
||
CORE_ADDR struct_addr)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
int argnum;
|
||
int argreg;
|
||
int nstack;
|
||
struct stack_item *si = NULL;
|
||
int use_vfp_abi;
|
||
struct type *ftype;
|
||
unsigned vfp_regs_free = (1 << 16) - 1;
|
||
|
||
/* Determine the type of this function and whether the VFP ABI
|
||
applies. */
|
||
ftype = check_typedef (value_type (function));
|
||
if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
|
||
ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
|
||
use_vfp_abi = arm_vfp_abi_for_function (gdbarch, ftype);
|
||
|
||
/* Set the return address. For the ARM, the return breakpoint is
|
||
always at BP_ADDR. */
|
||
if (arm_pc_is_thumb (bp_addr))
|
||
bp_addr |= 1;
|
||
regcache_cooked_write_unsigned (regcache, ARM_LR_REGNUM, bp_addr);
|
||
|
||
/* Walk through the list of args and determine how large a temporary
|
||
stack is required. Need to take care here as structs may be
|
||
passed on the stack, and we have to to push them. */
|
||
nstack = 0;
|
||
|
||
argreg = ARM_A1_REGNUM;
|
||
nstack = 0;
|
||
|
||
/* The struct_return pointer occupies the first parameter
|
||
passing register. */
|
||
if (struct_return)
|
||
{
|
||
if (arm_debug)
|
||
fprintf_unfiltered (gdb_stdlog, "struct return in %s = %s\n",
|
||
gdbarch_register_name (gdbarch, argreg),
|
||
paddress (gdbarch, struct_addr));
|
||
regcache_cooked_write_unsigned (regcache, argreg, struct_addr);
|
||
argreg++;
|
||
}
|
||
|
||
for (argnum = 0; argnum < nargs; argnum++)
|
||
{
|
||
int len;
|
||
struct type *arg_type;
|
||
struct type *target_type;
|
||
enum type_code typecode;
|
||
bfd_byte *val;
|
||
int align;
|
||
enum arm_vfp_cprc_base_type vfp_base_type;
|
||
int vfp_base_count;
|
||
int may_use_core_reg = 1;
|
||
|
||
arg_type = check_typedef (value_type (args[argnum]));
|
||
len = TYPE_LENGTH (arg_type);
|
||
target_type = TYPE_TARGET_TYPE (arg_type);
|
||
typecode = TYPE_CODE (arg_type);
|
||
val = value_contents_writeable (args[argnum]);
|
||
|
||
align = arm_type_align (arg_type);
|
||
/* Round alignment up to a whole number of words. */
|
||
align = (align + INT_REGISTER_SIZE - 1) & ~(INT_REGISTER_SIZE - 1);
|
||
/* Different ABIs have different maximum alignments. */
|
||
if (gdbarch_tdep (gdbarch)->arm_abi == ARM_ABI_APCS)
|
||
{
|
||
/* The APCS ABI only requires word alignment. */
|
||
align = INT_REGISTER_SIZE;
|
||
}
|
||
else
|
||
{
|
||
/* The AAPCS requires at most doubleword alignment. */
|
||
if (align > INT_REGISTER_SIZE * 2)
|
||
align = INT_REGISTER_SIZE * 2;
|
||
}
|
||
|
||
if (use_vfp_abi
|
||
&& arm_vfp_call_candidate (arg_type, &vfp_base_type,
|
||
&vfp_base_count))
|
||
{
|
||
int regno;
|
||
int unit_length;
|
||
int shift;
|
||
unsigned mask;
|
||
|
||
/* Because this is a CPRC it cannot go in a core register or
|
||
cause a core register to be skipped for alignment.
|
||
Either it goes in VFP registers and the rest of this loop
|
||
iteration is skipped for this argument, or it goes on the
|
||
stack (and the stack alignment code is correct for this
|
||
case). */
|
||
may_use_core_reg = 0;
|
||
|
||
unit_length = arm_vfp_cprc_unit_length (vfp_base_type);
|
||
shift = unit_length / 4;
|
||
mask = (1 << (shift * vfp_base_count)) - 1;
|
||
for (regno = 0; regno < 16; regno += shift)
|
||
if (((vfp_regs_free >> regno) & mask) == mask)
|
||
break;
|
||
|
||
if (regno < 16)
|
||
{
|
||
int reg_char;
|
||
int reg_scaled;
|
||
int i;
|
||
|
||
vfp_regs_free &= ~(mask << regno);
|
||
reg_scaled = regno / shift;
|
||
reg_char = arm_vfp_cprc_reg_char (vfp_base_type);
|
||
for (i = 0; i < vfp_base_count; i++)
|
||
{
|
||
char name_buf[4];
|
||
int regnum;
|
||
if (reg_char == 'q')
|
||
arm_neon_quad_write (gdbarch, regcache, reg_scaled + i,
|
||
val + i * unit_length);
|
||
else
|
||
{
|
||
sprintf (name_buf, "%c%d", reg_char, reg_scaled + i);
|
||
regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
|
||
strlen (name_buf));
|
||
regcache_cooked_write (regcache, regnum,
|
||
val + i * unit_length);
|
||
}
|
||
}
|
||
continue;
|
||
}
|
||
else
|
||
{
|
||
/* This CPRC could not go in VFP registers, so all VFP
|
||
registers are now marked as used. */
|
||
vfp_regs_free = 0;
|
||
}
|
||
}
|
||
|
||
/* Push stack padding for dowubleword alignment. */
|
||
if (nstack & (align - 1))
|
||
{
|
||
si = push_stack_item (si, val, INT_REGISTER_SIZE);
|
||
nstack += INT_REGISTER_SIZE;
|
||
}
|
||
|
||
/* Doubleword aligned quantities must go in even register pairs. */
|
||
if (may_use_core_reg
|
||
&& argreg <= ARM_LAST_ARG_REGNUM
|
||
&& align > INT_REGISTER_SIZE
|
||
&& argreg & 1)
|
||
argreg++;
|
||
|
||
/* If the argument is a pointer to a function, and it is a
|
||
Thumb function, create a LOCAL copy of the value and set
|
||
the THUMB bit in it. */
|
||
if (TYPE_CODE_PTR == typecode
|
||
&& target_type != NULL
|
||
&& TYPE_CODE_FUNC == TYPE_CODE (target_type))
|
||
{
|
||
CORE_ADDR regval = extract_unsigned_integer (val, len, byte_order);
|
||
if (arm_pc_is_thumb (regval))
|
||
{
|
||
val = alloca (len);
|
||
store_unsigned_integer (val, len, byte_order,
|
||
MAKE_THUMB_ADDR (regval));
|
||
}
|
||
}
|
||
|
||
/* Copy the argument to general registers or the stack in
|
||
register-sized pieces. Large arguments are split between
|
||
registers and stack. */
|
||
while (len > 0)
|
||
{
|
||
int partial_len = len < INT_REGISTER_SIZE ? len : INT_REGISTER_SIZE;
|
||
|
||
if (may_use_core_reg && argreg <= ARM_LAST_ARG_REGNUM)
|
||
{
|
||
/* The argument is being passed in a general purpose
|
||
register. */
|
||
CORE_ADDR regval
|
||
= extract_unsigned_integer (val, partial_len, byte_order);
|
||
if (byte_order == BFD_ENDIAN_BIG)
|
||
regval <<= (INT_REGISTER_SIZE - partial_len) * 8;
|
||
if (arm_debug)
|
||
fprintf_unfiltered (gdb_stdlog, "arg %d in %s = 0x%s\n",
|
||
argnum,
|
||
gdbarch_register_name
|
||
(gdbarch, argreg),
|
||
phex (regval, INT_REGISTER_SIZE));
|
||
regcache_cooked_write_unsigned (regcache, argreg, regval);
|
||
argreg++;
|
||
}
|
||
else
|
||
{
|
||
/* Push the arguments onto the stack. */
|
||
if (arm_debug)
|
||
fprintf_unfiltered (gdb_stdlog, "arg %d @ sp + %d\n",
|
||
argnum, nstack);
|
||
si = push_stack_item (si, val, INT_REGISTER_SIZE);
|
||
nstack += INT_REGISTER_SIZE;
|
||
}
|
||
|
||
len -= partial_len;
|
||
val += partial_len;
|
||
}
|
||
}
|
||
/* If we have an odd number of words to push, then decrement the stack
|
||
by one word now, so first stack argument will be dword aligned. */
|
||
if (nstack & 4)
|
||
sp -= 4;
|
||
|
||
while (si)
|
||
{
|
||
sp -= si->len;
|
||
write_memory (sp, si->data, si->len);
|
||
si = pop_stack_item (si);
|
||
}
|
||
|
||
/* Finally, update teh SP register. */
|
||
regcache_cooked_write_unsigned (regcache, ARM_SP_REGNUM, sp);
|
||
|
||
return sp;
|
||
}
|
||
|
||
|
||
/* Always align the frame to an 8-byte boundary. This is required on
|
||
some platforms and harmless on the rest. */
|
||
|
||
static CORE_ADDR
|
||
arm_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
|
||
{
|
||
/* Align the stack to eight bytes. */
|
||
return sp & ~ (CORE_ADDR) 7;
|
||
}
|
||
|
||
static void
|
||
print_fpu_flags (int flags)
|
||
{
|
||
if (flags & (1 << 0))
|
||
fputs ("IVO ", stdout);
|
||
if (flags & (1 << 1))
|
||
fputs ("DVZ ", stdout);
|
||
if (flags & (1 << 2))
|
||
fputs ("OFL ", stdout);
|
||
if (flags & (1 << 3))
|
||
fputs ("UFL ", stdout);
|
||
if (flags & (1 << 4))
|
||
fputs ("INX ", stdout);
|
||
putchar ('\n');
|
||
}
|
||
|
||
/* Print interesting information about the floating point processor
|
||
(if present) or emulator. */
|
||
static void
|
||
arm_print_float_info (struct gdbarch *gdbarch, struct ui_file *file,
|
||
struct frame_info *frame, const char *args)
|
||
{
|
||
unsigned long status = get_frame_register_unsigned (frame, ARM_FPS_REGNUM);
|
||
int type;
|
||
|
||
type = (status >> 24) & 127;
|
||
if (status & (1 << 31))
|
||
printf (_("Hardware FPU type %d\n"), type);
|
||
else
|
||
printf (_("Software FPU type %d\n"), type);
|
||
/* i18n: [floating point unit] mask */
|
||
fputs (_("mask: "), stdout);
|
||
print_fpu_flags (status >> 16);
|
||
/* i18n: [floating point unit] flags */
|
||
fputs (_("flags: "), stdout);
|
||
print_fpu_flags (status);
|
||
}
|
||
|
||
/* Construct the ARM extended floating point type. */
|
||
static struct type *
|
||
arm_ext_type (struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
if (!tdep->arm_ext_type)
|
||
tdep->arm_ext_type
|
||
= arch_float_type (gdbarch, -1, "builtin_type_arm_ext",
|
||
floatformats_arm_ext);
|
||
|
||
return tdep->arm_ext_type;
|
||
}
|
||
|
||
static struct type *
|
||
arm_neon_double_type (struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
if (tdep->neon_double_type == NULL)
|
||
{
|
||
struct type *t, *elem;
|
||
|
||
t = arch_composite_type (gdbarch, "__gdb_builtin_type_neon_d",
|
||
TYPE_CODE_UNION);
|
||
elem = builtin_type (gdbarch)->builtin_uint8;
|
||
append_composite_type_field (t, "u8", init_vector_type (elem, 8));
|
||
elem = builtin_type (gdbarch)->builtin_uint16;
|
||
append_composite_type_field (t, "u16", init_vector_type (elem, 4));
|
||
elem = builtin_type (gdbarch)->builtin_uint32;
|
||
append_composite_type_field (t, "u32", init_vector_type (elem, 2));
|
||
elem = builtin_type (gdbarch)->builtin_uint64;
|
||
append_composite_type_field (t, "u64", elem);
|
||
elem = builtin_type (gdbarch)->builtin_float;
|
||
append_composite_type_field (t, "f32", init_vector_type (elem, 2));
|
||
elem = builtin_type (gdbarch)->builtin_double;
|
||
append_composite_type_field (t, "f64", elem);
|
||
|
||
TYPE_VECTOR (t) = 1;
|
||
TYPE_NAME (t) = "neon_d";
|
||
tdep->neon_double_type = t;
|
||
}
|
||
|
||
return tdep->neon_double_type;
|
||
}
|
||
|
||
/* FIXME: The vector types are not correctly ordered on big-endian
|
||
targets. Just as s0 is the low bits of d0, d0[0] is also the low
|
||
bits of d0 - regardless of what unit size is being held in d0. So
|
||
the offset of the first uint8 in d0 is 7, but the offset of the
|
||
first float is 4. This code works as-is for little-endian
|
||
targets. */
|
||
|
||
static struct type *
|
||
arm_neon_quad_type (struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
if (tdep->neon_quad_type == NULL)
|
||
{
|
||
struct type *t, *elem;
|
||
|
||
t = arch_composite_type (gdbarch, "__gdb_builtin_type_neon_q",
|
||
TYPE_CODE_UNION);
|
||
elem = builtin_type (gdbarch)->builtin_uint8;
|
||
append_composite_type_field (t, "u8", init_vector_type (elem, 16));
|
||
elem = builtin_type (gdbarch)->builtin_uint16;
|
||
append_composite_type_field (t, "u16", init_vector_type (elem, 8));
|
||
elem = builtin_type (gdbarch)->builtin_uint32;
|
||
append_composite_type_field (t, "u32", init_vector_type (elem, 4));
|
||
elem = builtin_type (gdbarch)->builtin_uint64;
|
||
append_composite_type_field (t, "u64", init_vector_type (elem, 2));
|
||
elem = builtin_type (gdbarch)->builtin_float;
|
||
append_composite_type_field (t, "f32", init_vector_type (elem, 4));
|
||
elem = builtin_type (gdbarch)->builtin_double;
|
||
append_composite_type_field (t, "f64", init_vector_type (elem, 2));
|
||
|
||
TYPE_VECTOR (t) = 1;
|
||
TYPE_NAME (t) = "neon_q";
|
||
tdep->neon_quad_type = t;
|
||
}
|
||
|
||
return tdep->neon_quad_type;
|
||
}
|
||
|
||
/* Return the GDB type object for the "standard" data type of data in
|
||
register N. */
|
||
|
||
static struct type *
|
||
arm_register_type (struct gdbarch *gdbarch, int regnum)
|
||
{
|
||
int num_regs = gdbarch_num_regs (gdbarch);
|
||
|
||
if (gdbarch_tdep (gdbarch)->have_vfp_pseudos
|
||
&& regnum >= num_regs && regnum < num_regs + 32)
|
||
return builtin_type (gdbarch)->builtin_float;
|
||
|
||
if (gdbarch_tdep (gdbarch)->have_neon_pseudos
|
||
&& regnum >= num_regs + 32 && regnum < num_regs + 32 + 16)
|
||
return arm_neon_quad_type (gdbarch);
|
||
|
||
/* If the target description has register information, we are only
|
||
in this function so that we can override the types of
|
||
double-precision registers for NEON. */
|
||
if (tdesc_has_registers (gdbarch_target_desc (gdbarch)))
|
||
{
|
||
struct type *t = tdesc_register_type (gdbarch, regnum);
|
||
|
||
if (regnum >= ARM_D0_REGNUM && regnum < ARM_D0_REGNUM + 32
|
||
&& TYPE_CODE (t) == TYPE_CODE_FLT
|
||
&& gdbarch_tdep (gdbarch)->have_neon)
|
||
return arm_neon_double_type (gdbarch);
|
||
else
|
||
return t;
|
||
}
|
||
|
||
if (regnum >= ARM_F0_REGNUM && regnum < ARM_F0_REGNUM + NUM_FREGS)
|
||
{
|
||
if (!gdbarch_tdep (gdbarch)->have_fpa_registers)
|
||
return builtin_type (gdbarch)->builtin_void;
|
||
|
||
return arm_ext_type (gdbarch);
|
||
}
|
||
else if (regnum == ARM_SP_REGNUM)
|
||
return builtin_type (gdbarch)->builtin_data_ptr;
|
||
else if (regnum == ARM_PC_REGNUM)
|
||
return builtin_type (gdbarch)->builtin_func_ptr;
|
||
else if (regnum >= ARRAY_SIZE (arm_register_names))
|
||
/* These registers are only supported on targets which supply
|
||
an XML description. */
|
||
return builtin_type (gdbarch)->builtin_int0;
|
||
else
|
||
return builtin_type (gdbarch)->builtin_uint32;
|
||
}
|
||
|
||
/* Map a DWARF register REGNUM onto the appropriate GDB register
|
||
number. */
|
||
|
||
static int
|
||
arm_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
|
||
{
|
||
/* Core integer regs. */
|
||
if (reg >= 0 && reg <= 15)
|
||
return reg;
|
||
|
||
/* Legacy FPA encoding. These were once used in a way which
|
||
overlapped with VFP register numbering, so their use is
|
||
discouraged, but GDB doesn't support the ARM toolchain
|
||
which used them for VFP. */
|
||
if (reg >= 16 && reg <= 23)
|
||
return ARM_F0_REGNUM + reg - 16;
|
||
|
||
/* New assignments for the FPA registers. */
|
||
if (reg >= 96 && reg <= 103)
|
||
return ARM_F0_REGNUM + reg - 96;
|
||
|
||
/* WMMX register assignments. */
|
||
if (reg >= 104 && reg <= 111)
|
||
return ARM_WCGR0_REGNUM + reg - 104;
|
||
|
||
if (reg >= 112 && reg <= 127)
|
||
return ARM_WR0_REGNUM + reg - 112;
|
||
|
||
if (reg >= 192 && reg <= 199)
|
||
return ARM_WC0_REGNUM + reg - 192;
|
||
|
||
/* VFP v2 registers. A double precision value is actually
|
||
in d1 rather than s2, but the ABI only defines numbering
|
||
for the single precision registers. This will "just work"
|
||
in GDB for little endian targets (we'll read eight bytes,
|
||
starting in s0 and then progressing to s1), but will be
|
||
reversed on big endian targets with VFP. This won't
|
||
be a problem for the new Neon quad registers; you're supposed
|
||
to use DW_OP_piece for those. */
|
||
if (reg >= 64 && reg <= 95)
|
||
{
|
||
char name_buf[4];
|
||
|
||
sprintf (name_buf, "s%d", reg - 64);
|
||
return user_reg_map_name_to_regnum (gdbarch, name_buf,
|
||
strlen (name_buf));
|
||
}
|
||
|
||
/* VFP v3 / Neon registers. This range is also used for VFP v2
|
||
registers, except that it now describes d0 instead of s0. */
|
||
if (reg >= 256 && reg <= 287)
|
||
{
|
||
char name_buf[4];
|
||
|
||
sprintf (name_buf, "d%d", reg - 256);
|
||
return user_reg_map_name_to_regnum (gdbarch, name_buf,
|
||
strlen (name_buf));
|
||
}
|
||
|
||
return -1;
|
||
}
|
||
|
||
/* Map GDB internal REGNUM onto the Arm simulator register numbers. */
|
||
static int
|
||
arm_register_sim_regno (struct gdbarch *gdbarch, int regnum)
|
||
{
|
||
int reg = regnum;
|
||
gdb_assert (reg >= 0 && reg < gdbarch_num_regs (gdbarch));
|
||
|
||
if (regnum >= ARM_WR0_REGNUM && regnum <= ARM_WR15_REGNUM)
|
||
return regnum - ARM_WR0_REGNUM + SIM_ARM_IWMMXT_COP0R0_REGNUM;
|
||
|
||
if (regnum >= ARM_WC0_REGNUM && regnum <= ARM_WC7_REGNUM)
|
||
return regnum - ARM_WC0_REGNUM + SIM_ARM_IWMMXT_COP1R0_REGNUM;
|
||
|
||
if (regnum >= ARM_WCGR0_REGNUM && regnum <= ARM_WCGR7_REGNUM)
|
||
return regnum - ARM_WCGR0_REGNUM + SIM_ARM_IWMMXT_COP1R8_REGNUM;
|
||
|
||
if (reg < NUM_GREGS)
|
||
return SIM_ARM_R0_REGNUM + reg;
|
||
reg -= NUM_GREGS;
|
||
|
||
if (reg < NUM_FREGS)
|
||
return SIM_ARM_FP0_REGNUM + reg;
|
||
reg -= NUM_FREGS;
|
||
|
||
if (reg < NUM_SREGS)
|
||
return SIM_ARM_FPS_REGNUM + reg;
|
||
reg -= NUM_SREGS;
|
||
|
||
internal_error (__FILE__, __LINE__, _("Bad REGNUM %d"), regnum);
|
||
}
|
||
|
||
/* NOTE: cagney/2001-08-20: Both convert_from_extended() and
|
||
convert_to_extended() use floatformat_arm_ext_littlebyte_bigword.
|
||
It is thought that this is is the floating-point register format on
|
||
little-endian systems. */
|
||
|
||
static void
|
||
convert_from_extended (const struct floatformat *fmt, const void *ptr,
|
||
void *dbl, int endianess)
|
||
{
|
||
DOUBLEST d;
|
||
|
||
if (endianess == BFD_ENDIAN_BIG)
|
||
floatformat_to_doublest (&floatformat_arm_ext_big, ptr, &d);
|
||
else
|
||
floatformat_to_doublest (&floatformat_arm_ext_littlebyte_bigword,
|
||
ptr, &d);
|
||
floatformat_from_doublest (fmt, &d, dbl);
|
||
}
|
||
|
||
static void
|
||
convert_to_extended (const struct floatformat *fmt, void *dbl, const void *ptr,
|
||
int endianess)
|
||
{
|
||
DOUBLEST d;
|
||
|
||
floatformat_to_doublest (fmt, ptr, &d);
|
||
if (endianess == BFD_ENDIAN_BIG)
|
||
floatformat_from_doublest (&floatformat_arm_ext_big, &d, dbl);
|
||
else
|
||
floatformat_from_doublest (&floatformat_arm_ext_littlebyte_bigword,
|
||
&d, dbl);
|
||
}
|
||
|
||
static int
|
||
condition_true (unsigned long cond, unsigned long status_reg)
|
||
{
|
||
if (cond == INST_AL || cond == INST_NV)
|
||
return 1;
|
||
|
||
switch (cond)
|
||
{
|
||
case INST_EQ:
|
||
return ((status_reg & FLAG_Z) != 0);
|
||
case INST_NE:
|
||
return ((status_reg & FLAG_Z) == 0);
|
||
case INST_CS:
|
||
return ((status_reg & FLAG_C) != 0);
|
||
case INST_CC:
|
||
return ((status_reg & FLAG_C) == 0);
|
||
case INST_MI:
|
||
return ((status_reg & FLAG_N) != 0);
|
||
case INST_PL:
|
||
return ((status_reg & FLAG_N) == 0);
|
||
case INST_VS:
|
||
return ((status_reg & FLAG_V) != 0);
|
||
case INST_VC:
|
||
return ((status_reg & FLAG_V) == 0);
|
||
case INST_HI:
|
||
return ((status_reg & (FLAG_C | FLAG_Z)) == FLAG_C);
|
||
case INST_LS:
|
||
return ((status_reg & (FLAG_C | FLAG_Z)) != FLAG_C);
|
||
case INST_GE:
|
||
return (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0));
|
||
case INST_LT:
|
||
return (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0));
|
||
case INST_GT:
|
||
return (((status_reg & FLAG_Z) == 0)
|
||
&& (((status_reg & FLAG_N) == 0)
|
||
== ((status_reg & FLAG_V) == 0)));
|
||
case INST_LE:
|
||
return (((status_reg & FLAG_Z) != 0)
|
||
|| (((status_reg & FLAG_N) == 0)
|
||
!= ((status_reg & FLAG_V) == 0)));
|
||
}
|
||
return 1;
|
||
}
|
||
|
||
/* Support routines for single stepping. Calculate the next PC value. */
|
||
#define submask(x) ((1L << ((x) + 1)) - 1)
|
||
#define bit(obj,st) (((obj) >> (st)) & 1)
|
||
#define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st)))
|
||
#define sbits(obj,st,fn) \
|
||
((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st))))
|
||
#define BranchDest(addr,instr) \
|
||
((CORE_ADDR) (((long) (addr)) + 8 + (sbits (instr, 0, 23) << 2)))
|
||
#define ARM_PC_32 1
|
||
|
||
static unsigned long
|
||
shifted_reg_val (struct frame_info *frame, unsigned long inst, int carry,
|
||
unsigned long pc_val, unsigned long status_reg)
|
||
{
|
||
unsigned long res, shift;
|
||
int rm = bits (inst, 0, 3);
|
||
unsigned long shifttype = bits (inst, 5, 6);
|
||
|
||
if (bit (inst, 4))
|
||
{
|
||
int rs = bits (inst, 8, 11);
|
||
shift = (rs == 15 ? pc_val + 8
|
||
: get_frame_register_unsigned (frame, rs)) & 0xFF;
|
||
}
|
||
else
|
||
shift = bits (inst, 7, 11);
|
||
|
||
res = (rm == 15
|
||
? ((pc_val | (ARM_PC_32 ? 0 : status_reg))
|
||
+ (bit (inst, 4) ? 12 : 8))
|
||
: get_frame_register_unsigned (frame, rm));
|
||
|
||
switch (shifttype)
|
||
{
|
||
case 0: /* LSL */
|
||
res = shift >= 32 ? 0 : res << shift;
|
||
break;
|
||
|
||
case 1: /* LSR */
|
||
res = shift >= 32 ? 0 : res >> shift;
|
||
break;
|
||
|
||
case 2: /* ASR */
|
||
if (shift >= 32)
|
||
shift = 31;
|
||
res = ((res & 0x80000000L)
|
||
? ~((~res) >> shift) : res >> shift);
|
||
break;
|
||
|
||
case 3: /* ROR/RRX */
|
||
shift &= 31;
|
||
if (shift == 0)
|
||
res = (res >> 1) | (carry ? 0x80000000L : 0);
|
||
else
|
||
res = (res >> shift) | (res << (32 - shift));
|
||
break;
|
||
}
|
||
|
||
return res & 0xffffffff;
|
||
}
|
||
|
||
/* Return number of 1-bits in VAL. */
|
||
|
||
static int
|
||
bitcount (unsigned long val)
|
||
{
|
||
int nbits;
|
||
for (nbits = 0; val != 0; nbits++)
|
||
val &= val - 1; /* delete rightmost 1-bit in val */
|
||
return nbits;
|
||
}
|
||
|
||
/* Return the size in bytes of the complete Thumb instruction whose
|
||
first halfword is INST1. */
|
||
|
||
static int
|
||
thumb_insn_size (unsigned short inst1)
|
||
{
|
||
if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
|
||
return 4;
|
||
else
|
||
return 2;
|
||
}
|
||
|
||
static int
|
||
thumb_advance_itstate (unsigned int itstate)
|
||
{
|
||
/* Preserve IT[7:5], the first three bits of the condition. Shift
|
||
the upcoming condition flags left by one bit. */
|
||
itstate = (itstate & 0xe0) | ((itstate << 1) & 0x1f);
|
||
|
||
/* If we have finished the IT block, clear the state. */
|
||
if ((itstate & 0x0f) == 0)
|
||
itstate = 0;
|
||
|
||
return itstate;
|
||
}
|
||
|
||
/* Find the next PC after the current instruction executes. In some
|
||
cases we can not statically determine the answer (see the IT state
|
||
handling in this function); in that case, a breakpoint may be
|
||
inserted in addition to the returned PC, which will be used to set
|
||
another breakpoint by our caller. */
|
||
|
||
static CORE_ADDR
|
||
thumb_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc, int insert_bkpt)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
struct address_space *aspace = get_frame_address_space (frame);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
|
||
unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */
|
||
unsigned short inst1;
|
||
CORE_ADDR nextpc = pc + 2; /* default is next instruction */
|
||
unsigned long offset;
|
||
ULONGEST status, itstate;
|
||
|
||
nextpc = MAKE_THUMB_ADDR (nextpc);
|
||
pc_val = MAKE_THUMB_ADDR (pc_val);
|
||
|
||
inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
|
||
|
||
/* Thumb-2 conditional execution support. There are eight bits in
|
||
the CPSR which describe conditional execution state. Once
|
||
reconstructed (they're in a funny order), the low five bits
|
||
describe the low bit of the condition for each instruction and
|
||
how many instructions remain. The high three bits describe the
|
||
base condition. One of the low four bits will be set if an IT
|
||
block is active. These bits read as zero on earlier
|
||
processors. */
|
||
status = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
|
||
itstate = ((status >> 8) & 0xfc) | ((status >> 25) & 0x3);
|
||
|
||
/* If-Then handling. On GNU/Linux, where this routine is used, we
|
||
use an undefined instruction as a breakpoint. Unlike BKPT, IT
|
||
can disable execution of the undefined instruction. So we might
|
||
miss the breakpoint if we set it on a skipped conditional
|
||
instruction. Because conditional instructions can change the
|
||
flags, affecting the execution of further instructions, we may
|
||
need to set two breakpoints. */
|
||
|
||
if (gdbarch_tdep (gdbarch)->thumb2_breakpoint != NULL)
|
||
{
|
||
if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
|
||
{
|
||
/* An IT instruction. Because this instruction does not
|
||
modify the flags, we can accurately predict the next
|
||
executed instruction. */
|
||
itstate = inst1 & 0x00ff;
|
||
pc += thumb_insn_size (inst1);
|
||
|
||
while (itstate != 0 && ! condition_true (itstate >> 4, status))
|
||
{
|
||
inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
|
||
pc += thumb_insn_size (inst1);
|
||
itstate = thumb_advance_itstate (itstate);
|
||
}
|
||
|
||
return MAKE_THUMB_ADDR (pc);
|
||
}
|
||
else if (itstate != 0)
|
||
{
|
||
/* We are in a conditional block. Check the condition. */
|
||
if (! condition_true (itstate >> 4, status))
|
||
{
|
||
/* Advance to the next executed instruction. */
|
||
pc += thumb_insn_size (inst1);
|
||
itstate = thumb_advance_itstate (itstate);
|
||
|
||
while (itstate != 0 && ! condition_true (itstate >> 4, status))
|
||
{
|
||
inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
|
||
pc += thumb_insn_size (inst1);
|
||
itstate = thumb_advance_itstate (itstate);
|
||
}
|
||
|
||
return MAKE_THUMB_ADDR (pc);
|
||
}
|
||
else if ((itstate & 0x0f) == 0x08)
|
||
{
|
||
/* This is the last instruction of the conditional
|
||
block, and it is executed. We can handle it normally
|
||
because the following instruction is not conditional,
|
||
and we must handle it normally because it is
|
||
permitted to branch. Fall through. */
|
||
}
|
||
else
|
||
{
|
||
int cond_negated;
|
||
|
||
/* There are conditional instructions after this one.
|
||
If this instruction modifies the flags, then we can
|
||
not predict what the next executed instruction will
|
||
be. Fortunately, this instruction is architecturally
|
||
forbidden to branch; we know it will fall through.
|
||
Start by skipping past it. */
|
||
pc += thumb_insn_size (inst1);
|
||
itstate = thumb_advance_itstate (itstate);
|
||
|
||
/* Set a breakpoint on the following instruction. */
|
||
gdb_assert ((itstate & 0x0f) != 0);
|
||
if (insert_bkpt)
|
||
insert_single_step_breakpoint (gdbarch, aspace, pc);
|
||
cond_negated = (itstate >> 4) & 1;
|
||
|
||
/* Skip all following instructions with the same
|
||
condition. If there is a later instruction in the IT
|
||
block with the opposite condition, set the other
|
||
breakpoint there. If not, then set a breakpoint on
|
||
the instruction after the IT block. */
|
||
do
|
||
{
|
||
inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
|
||
pc += thumb_insn_size (inst1);
|
||
itstate = thumb_advance_itstate (itstate);
|
||
}
|
||
while (itstate != 0 && ((itstate >> 4) & 1) == cond_negated);
|
||
|
||
return MAKE_THUMB_ADDR (pc);
|
||
}
|
||
}
|
||
}
|
||
else if (itstate & 0x0f)
|
||
{
|
||
/* We are in a conditional block. Check the condition. */
|
||
int cond = itstate >> 4;
|
||
|
||
if (! condition_true (cond, status))
|
||
{
|
||
/* Advance to the next instruction. All the 32-bit
|
||
instructions share a common prefix. */
|
||
if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
|
||
return MAKE_THUMB_ADDR (pc + 4);
|
||
else
|
||
return MAKE_THUMB_ADDR (pc + 2);
|
||
}
|
||
|
||
/* Otherwise, handle the instruction normally. */
|
||
}
|
||
|
||
if ((inst1 & 0xff00) == 0xbd00) /* pop {rlist, pc} */
|
||
{
|
||
CORE_ADDR sp;
|
||
|
||
/* Fetch the saved PC from the stack. It's stored above
|
||
all of the other registers. */
|
||
offset = bitcount (bits (inst1, 0, 7)) * INT_REGISTER_SIZE;
|
||
sp = get_frame_register_unsigned (frame, ARM_SP_REGNUM);
|
||
nextpc = read_memory_unsigned_integer (sp + offset, 4, byte_order);
|
||
}
|
||
else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */
|
||
{
|
||
unsigned long cond = bits (inst1, 8, 11);
|
||
if (cond != 0x0f && condition_true (cond, status)) /* 0x0f = SWI */
|
||
nextpc = pc_val + (sbits (inst1, 0, 7) << 1);
|
||
}
|
||
else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */
|
||
{
|
||
nextpc = pc_val + (sbits (inst1, 0, 10) << 1);
|
||
}
|
||
else if ((inst1 & 0xe000) == 0xe000) /* 32-bit instruction */
|
||
{
|
||
unsigned short inst2;
|
||
inst2 = read_memory_unsigned_integer (pc + 2, 2, byte_order_for_code);
|
||
|
||
/* Default to the next instruction. */
|
||
nextpc = pc + 4;
|
||
nextpc = MAKE_THUMB_ADDR (nextpc);
|
||
|
||
if ((inst1 & 0xf800) == 0xf000 && (inst2 & 0x8000) == 0x8000)
|
||
{
|
||
/* Branches and miscellaneous control instructions. */
|
||
|
||
if ((inst2 & 0x1000) != 0 || (inst2 & 0xd001) == 0xc000)
|
||
{
|
||
/* B, BL, BLX. */
|
||
int j1, j2, imm1, imm2;
|
||
|
||
imm1 = sbits (inst1, 0, 10);
|
||
imm2 = bits (inst2, 0, 10);
|
||
j1 = bit (inst2, 13);
|
||
j2 = bit (inst2, 11);
|
||
|
||
offset = ((imm1 << 12) + (imm2 << 1));
|
||
offset ^= ((!j2) << 22) | ((!j1) << 23);
|
||
|
||
nextpc = pc_val + offset;
|
||
/* For BLX make sure to clear the low bits. */
|
||
if (bit (inst2, 12) == 0)
|
||
nextpc = nextpc & 0xfffffffc;
|
||
}
|
||
else if (inst1 == 0xf3de && (inst2 & 0xff00) == 0x3f00)
|
||
{
|
||
/* SUBS PC, LR, #imm8. */
|
||
nextpc = get_frame_register_unsigned (frame, ARM_LR_REGNUM);
|
||
nextpc -= inst2 & 0x00ff;
|
||
}
|
||
else if ((inst2 & 0xd000) == 0x8000 && (inst1 & 0x0380) != 0x0380)
|
||
{
|
||
/* Conditional branch. */
|
||
if (condition_true (bits (inst1, 6, 9), status))
|
||
{
|
||
int sign, j1, j2, imm1, imm2;
|
||
|
||
sign = sbits (inst1, 10, 10);
|
||
imm1 = bits (inst1, 0, 5);
|
||
imm2 = bits (inst2, 0, 10);
|
||
j1 = bit (inst2, 13);
|
||
j2 = bit (inst2, 11);
|
||
|
||
offset = (sign << 20) + (j2 << 19) + (j1 << 18);
|
||
offset += (imm1 << 12) + (imm2 << 1);
|
||
|
||
nextpc = pc_val + offset;
|
||
}
|
||
}
|
||
}
|
||
else if ((inst1 & 0xfe50) == 0xe810)
|
||
{
|
||
/* Load multiple or RFE. */
|
||
int rn, offset, load_pc = 1;
|
||
|
||
rn = bits (inst1, 0, 3);
|
||
if (bit (inst1, 7) && !bit (inst1, 8))
|
||
{
|
||
/* LDMIA or POP */
|
||
if (!bit (inst2, 15))
|
||
load_pc = 0;
|
||
offset = bitcount (inst2) * 4 - 4;
|
||
}
|
||
else if (!bit (inst1, 7) && bit (inst1, 8))
|
||
{
|
||
/* LDMDB */
|
||
if (!bit (inst2, 15))
|
||
load_pc = 0;
|
||
offset = -4;
|
||
}
|
||
else if (bit (inst1, 7) && bit (inst1, 8))
|
||
{
|
||
/* RFEIA */
|
||
offset = 0;
|
||
}
|
||
else if (!bit (inst1, 7) && !bit (inst1, 8))
|
||
{
|
||
/* RFEDB */
|
||
offset = -8;
|
||
}
|
||
else
|
||
load_pc = 0;
|
||
|
||
if (load_pc)
|
||
{
|
||
CORE_ADDR addr = get_frame_register_unsigned (frame, rn);
|
||
nextpc = get_frame_memory_unsigned (frame, addr + offset, 4);
|
||
}
|
||
}
|
||
else if ((inst1 & 0xffef) == 0xea4f && (inst2 & 0xfff0) == 0x0f00)
|
||
{
|
||
/* MOV PC or MOVS PC. */
|
||
nextpc = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
|
||
nextpc = MAKE_THUMB_ADDR (nextpc);
|
||
}
|
||
else if ((inst1 & 0xff70) == 0xf850 && (inst2 & 0xf000) == 0xf000)
|
||
{
|
||
/* LDR PC. */
|
||
CORE_ADDR base;
|
||
int rn, load_pc = 1;
|
||
|
||
rn = bits (inst1, 0, 3);
|
||
base = get_frame_register_unsigned (frame, rn);
|
||
if (rn == 15)
|
||
{
|
||
base = (base + 4) & ~(CORE_ADDR) 0x3;
|
||
if (bit (inst1, 7))
|
||
base += bits (inst2, 0, 11);
|
||
else
|
||
base -= bits (inst2, 0, 11);
|
||
}
|
||
else if (bit (inst1, 7))
|
||
base += bits (inst2, 0, 11);
|
||
else if (bit (inst2, 11))
|
||
{
|
||
if (bit (inst2, 10))
|
||
{
|
||
if (bit (inst2, 9))
|
||
base += bits (inst2, 0, 7);
|
||
else
|
||
base -= bits (inst2, 0, 7);
|
||
}
|
||
}
|
||
else if ((inst2 & 0x0fc0) == 0x0000)
|
||
{
|
||
int shift = bits (inst2, 4, 5), rm = bits (inst2, 0, 3);
|
||
base += get_frame_register_unsigned (frame, rm) << shift;
|
||
}
|
||
else
|
||
/* Reserved. */
|
||
load_pc = 0;
|
||
|
||
if (load_pc)
|
||
nextpc = get_frame_memory_unsigned (frame, base, 4);
|
||
}
|
||
else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
|
||
{
|
||
/* TBB. */
|
||
CORE_ADDR table, offset, length;
|
||
|
||
table = get_frame_register_unsigned (frame, bits (inst1, 0, 3));
|
||
offset = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
|
||
length = 2 * get_frame_memory_unsigned (frame, table + offset, 1);
|
||
nextpc = pc_val + length;
|
||
}
|
||
else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
|
||
{
|
||
/* TBH. */
|
||
CORE_ADDR table, offset, length;
|
||
|
||
table = get_frame_register_unsigned (frame, bits (inst1, 0, 3));
|
||
offset = 2 * get_frame_register_unsigned (frame, bits (inst2, 0, 3));
|
||
length = 2 * get_frame_memory_unsigned (frame, table + offset, 2);
|
||
nextpc = pc_val + length;
|
||
}
|
||
}
|
||
else if ((inst1 & 0xff00) == 0x4700) /* bx REG, blx REG */
|
||
{
|
||
if (bits (inst1, 3, 6) == 0x0f)
|
||
nextpc = pc_val;
|
||
else
|
||
nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
|
||
}
|
||
else if ((inst1 & 0xf500) == 0xb100)
|
||
{
|
||
/* CBNZ or CBZ. */
|
||
int imm = (bit (inst1, 9) << 6) + (bits (inst1, 3, 7) << 1);
|
||
ULONGEST reg = get_frame_register_unsigned (frame, bits (inst1, 0, 2));
|
||
|
||
if (bit (inst1, 11) && reg != 0)
|
||
nextpc = pc_val + imm;
|
||
else if (!bit (inst1, 11) && reg == 0)
|
||
nextpc = pc_val + imm;
|
||
}
|
||
return nextpc;
|
||
}
|
||
|
||
/* Get the raw next address. PC is the current program counter, in
|
||
FRAME. INSERT_BKPT should be TRUE if we want a breakpoint set on
|
||
the alternative next instruction if there are two options.
|
||
|
||
The value returned has the execution state of the next instruction
|
||
encoded in it. Use IS_THUMB_ADDR () to see whether the instruction is
|
||
in Thumb-State, and gdbarch_addr_bits_remove () to get the plain memory
|
||
address.
|
||
*/
|
||
static CORE_ADDR
|
||
arm_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc, int insert_bkpt)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
|
||
unsigned long pc_val;
|
||
unsigned long this_instr;
|
||
unsigned long status;
|
||
CORE_ADDR nextpc;
|
||
|
||
if (arm_frame_is_thumb (frame))
|
||
return thumb_get_next_pc_raw (frame, pc, insert_bkpt);
|
||
|
||
pc_val = (unsigned long) pc;
|
||
this_instr = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
|
||
|
||
status = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
|
||
nextpc = (CORE_ADDR) (pc_val + 4); /* Default case */
|
||
|
||
if (bits (this_instr, 28, 31) == INST_NV)
|
||
switch (bits (this_instr, 24, 27))
|
||
{
|
||
case 0xa:
|
||
case 0xb:
|
||
{
|
||
/* Branch with Link and change to Thumb. */
|
||
nextpc = BranchDest (pc, this_instr);
|
||
nextpc |= bit (this_instr, 24) << 1;
|
||
nextpc = MAKE_THUMB_ADDR (nextpc);
|
||
break;
|
||
}
|
||
case 0xc:
|
||
case 0xd:
|
||
case 0xe:
|
||
/* Coprocessor register transfer. */
|
||
if (bits (this_instr, 12, 15) == 15)
|
||
error (_("Invalid update to pc in instruction"));
|
||
break;
|
||
}
|
||
else if (condition_true (bits (this_instr, 28, 31), status))
|
||
{
|
||
switch (bits (this_instr, 24, 27))
|
||
{
|
||
case 0x0:
|
||
case 0x1: /* data processing */
|
||
case 0x2:
|
||
case 0x3:
|
||
{
|
||
unsigned long operand1, operand2, result = 0;
|
||
unsigned long rn;
|
||
int c;
|
||
|
||
if (bits (this_instr, 12, 15) != 15)
|
||
break;
|
||
|
||
if (bits (this_instr, 22, 25) == 0
|
||
&& bits (this_instr, 4, 7) == 9) /* multiply */
|
||
error (_("Invalid update to pc in instruction"));
|
||
|
||
/* BX <reg>, BLX <reg> */
|
||
if (bits (this_instr, 4, 27) == 0x12fff1
|
||
|| bits (this_instr, 4, 27) == 0x12fff3)
|
||
{
|
||
rn = bits (this_instr, 0, 3);
|
||
nextpc = (rn == 15) ? pc_val + 8
|
||
: get_frame_register_unsigned (frame, rn);
|
||
return nextpc;
|
||
}
|
||
|
||
/* Multiply into PC */
|
||
c = (status & FLAG_C) ? 1 : 0;
|
||
rn = bits (this_instr, 16, 19);
|
||
operand1 = (rn == 15) ? pc_val + 8
|
||
: get_frame_register_unsigned (frame, rn);
|
||
|
||
if (bit (this_instr, 25))
|
||
{
|
||
unsigned long immval = bits (this_instr, 0, 7);
|
||
unsigned long rotate = 2 * bits (this_instr, 8, 11);
|
||
operand2 = ((immval >> rotate) | (immval << (32 - rotate)))
|
||
& 0xffffffff;
|
||
}
|
||
else /* operand 2 is a shifted register */
|
||
operand2 = shifted_reg_val (frame, this_instr, c, pc_val, status);
|
||
|
||
switch (bits (this_instr, 21, 24))
|
||
{
|
||
case 0x0: /*and */
|
||
result = operand1 & operand2;
|
||
break;
|
||
|
||
case 0x1: /*eor */
|
||
result = operand1 ^ operand2;
|
||
break;
|
||
|
||
case 0x2: /*sub */
|
||
result = operand1 - operand2;
|
||
break;
|
||
|
||
case 0x3: /*rsb */
|
||
result = operand2 - operand1;
|
||
break;
|
||
|
||
case 0x4: /*add */
|
||
result = operand1 + operand2;
|
||
break;
|
||
|
||
case 0x5: /*adc */
|
||
result = operand1 + operand2 + c;
|
||
break;
|
||
|
||
case 0x6: /*sbc */
|
||
result = operand1 - operand2 + c;
|
||
break;
|
||
|
||
case 0x7: /*rsc */
|
||
result = operand2 - operand1 + c;
|
||
break;
|
||
|
||
case 0x8:
|
||
case 0x9:
|
||
case 0xa:
|
||
case 0xb: /* tst, teq, cmp, cmn */
|
||
result = (unsigned long) nextpc;
|
||
break;
|
||
|
||
case 0xc: /*orr */
|
||
result = operand1 | operand2;
|
||
break;
|
||
|
||
case 0xd: /*mov */
|
||
/* Always step into a function. */
|
||
result = operand2;
|
||
break;
|
||
|
||
case 0xe: /*bic */
|
||
result = operand1 & ~operand2;
|
||
break;
|
||
|
||
case 0xf: /*mvn */
|
||
result = ~operand2;
|
||
break;
|
||
}
|
||
|
||
/* In 26-bit APCS the bottom two bits of the result are
|
||
ignored, and we always end up in ARM state. */
|
||
if (!arm_apcs_32)
|
||
nextpc = arm_addr_bits_remove (gdbarch, result);
|
||
else
|
||
nextpc = result;
|
||
|
||
break;
|
||
}
|
||
|
||
case 0x4:
|
||
case 0x5: /* data transfer */
|
||
case 0x6:
|
||
case 0x7:
|
||
if (bit (this_instr, 20))
|
||
{
|
||
/* load */
|
||
if (bits (this_instr, 12, 15) == 15)
|
||
{
|
||
/* rd == pc */
|
||
unsigned long rn;
|
||
unsigned long base;
|
||
|
||
if (bit (this_instr, 22))
|
||
error (_("Invalid update to pc in instruction"));
|
||
|
||
/* byte write to PC */
|
||
rn = bits (this_instr, 16, 19);
|
||
base = (rn == 15) ? pc_val + 8
|
||
: get_frame_register_unsigned (frame, rn);
|
||
if (bit (this_instr, 24))
|
||
{
|
||
/* pre-indexed */
|
||
int c = (status & FLAG_C) ? 1 : 0;
|
||
unsigned long offset =
|
||
(bit (this_instr, 25)
|
||
? shifted_reg_val (frame, this_instr, c, pc_val, status)
|
||
: bits (this_instr, 0, 11));
|
||
|
||
if (bit (this_instr, 23))
|
||
base += offset;
|
||
else
|
||
base -= offset;
|
||
}
|
||
nextpc = (CORE_ADDR) read_memory_integer ((CORE_ADDR) base,
|
||
4, byte_order);
|
||
}
|
||
}
|
||
break;
|
||
|
||
case 0x8:
|
||
case 0x9: /* block transfer */
|
||
if (bit (this_instr, 20))
|
||
{
|
||
/* LDM */
|
||
if (bit (this_instr, 15))
|
||
{
|
||
/* loading pc */
|
||
int offset = 0;
|
||
|
||
if (bit (this_instr, 23))
|
||
{
|
||
/* up */
|
||
unsigned long reglist = bits (this_instr, 0, 14);
|
||
offset = bitcount (reglist) * 4;
|
||
if (bit (this_instr, 24)) /* pre */
|
||
offset += 4;
|
||
}
|
||
else if (bit (this_instr, 24))
|
||
offset = -4;
|
||
|
||
{
|
||
unsigned long rn_val =
|
||
get_frame_register_unsigned (frame,
|
||
bits (this_instr, 16, 19));
|
||
nextpc =
|
||
(CORE_ADDR) read_memory_integer ((CORE_ADDR) (rn_val
|
||
+ offset),
|
||
4, byte_order);
|
||
}
|
||
}
|
||
}
|
||
break;
|
||
|
||
case 0xb: /* branch & link */
|
||
case 0xa: /* branch */
|
||
{
|
||
nextpc = BranchDest (pc, this_instr);
|
||
break;
|
||
}
|
||
|
||
case 0xc:
|
||
case 0xd:
|
||
case 0xe: /* coproc ops */
|
||
case 0xf: /* SWI */
|
||
break;
|
||
|
||
default:
|
||
fprintf_filtered (gdb_stderr, _("Bad bit-field extraction\n"));
|
||
return (pc);
|
||
}
|
||
}
|
||
|
||
return nextpc;
|
||
}
|
||
|
||
CORE_ADDR
|
||
arm_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
CORE_ADDR nextpc =
|
||
gdbarch_addr_bits_remove (gdbarch,
|
||
arm_get_next_pc_raw (frame, pc, TRUE));
|
||
if (nextpc == pc)
|
||
error (_("Infinite loop detected"));
|
||
return nextpc;
|
||
}
|
||
|
||
/* single_step() is called just before we want to resume the inferior,
|
||
if we want to single-step it but there is no hardware or kernel
|
||
single-step support. We find the target of the coming instruction
|
||
and breakpoint it. */
|
||
|
||
int
|
||
arm_software_single_step (struct frame_info *frame)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
struct address_space *aspace = get_frame_address_space (frame);
|
||
|
||
/* NOTE: This may insert the wrong breakpoint instruction when
|
||
single-stepping over a mode-changing instruction, if the
|
||
CPSR heuristics are used. */
|
||
|
||
CORE_ADDR next_pc = arm_get_next_pc (frame, get_frame_pc (frame));
|
||
insert_single_step_breakpoint (gdbarch, aspace, next_pc);
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Given BUF, which is OLD_LEN bytes ending at ENDADDR, expand
|
||
the buffer to be NEW_LEN bytes ending at ENDADDR. Return
|
||
NULL if an error occurs. BUF is freed. */
|
||
|
||
static gdb_byte *
|
||
extend_buffer_earlier (gdb_byte *buf, CORE_ADDR endaddr,
|
||
int old_len, int new_len)
|
||
{
|
||
gdb_byte *new_buf, *middle;
|
||
int bytes_to_read = new_len - old_len;
|
||
|
||
new_buf = xmalloc (new_len);
|
||
memcpy (new_buf + bytes_to_read, buf, old_len);
|
||
xfree (buf);
|
||
if (target_read_memory (endaddr - new_len, new_buf, bytes_to_read) != 0)
|
||
{
|
||
xfree (new_buf);
|
||
return NULL;
|
||
}
|
||
return new_buf;
|
||
}
|
||
|
||
/* An IT block is at most the 2-byte IT instruction followed by
|
||
four 4-byte instructions. The furthest back we must search to
|
||
find an IT block that affects the current instruction is thus
|
||
2 + 3 * 4 == 14 bytes. */
|
||
#define MAX_IT_BLOCK_PREFIX 14
|
||
|
||
/* Use a quick scan if there are more than this many bytes of
|
||
code. */
|
||
#define IT_SCAN_THRESHOLD 32
|
||
|
||
/* Adjust a breakpoint's address to move breakpoints out of IT blocks.
|
||
A breakpoint in an IT block may not be hit, depending on the
|
||
condition flags. */
|
||
static CORE_ADDR
|
||
arm_adjust_breakpoint_address (struct gdbarch *gdbarch, CORE_ADDR bpaddr)
|
||
{
|
||
gdb_byte *buf;
|
||
char map_type;
|
||
CORE_ADDR boundary, func_start;
|
||
int buf_len, buf2_len;
|
||
enum bfd_endian order = gdbarch_byte_order_for_code (gdbarch);
|
||
int i, any, last_it, last_it_count;
|
||
|
||
/* If we are using BKPT breakpoints, none of this is necessary. */
|
||
if (gdbarch_tdep (gdbarch)->thumb2_breakpoint == NULL)
|
||
return bpaddr;
|
||
|
||
/* ARM mode does not have this problem. */
|
||
if (!arm_pc_is_thumb (bpaddr))
|
||
return bpaddr;
|
||
|
||
/* We are setting a breakpoint in Thumb code that could potentially
|
||
contain an IT block. The first step is to find how much Thumb
|
||
code there is; we do not need to read outside of known Thumb
|
||
sequences. */
|
||
map_type = arm_find_mapping_symbol (bpaddr, &boundary);
|
||
if (map_type == 0)
|
||
/* Thumb-2 code must have mapping symbols to have a chance. */
|
||
return bpaddr;
|
||
|
||
bpaddr = gdbarch_addr_bits_remove (gdbarch, bpaddr);
|
||
|
||
if (find_pc_partial_function (bpaddr, NULL, &func_start, NULL)
|
||
&& func_start > boundary)
|
||
boundary = func_start;
|
||
|
||
/* Search for a candidate IT instruction. We have to do some fancy
|
||
footwork to distinguish a real IT instruction from the second
|
||
half of a 32-bit instruction, but there is no need for that if
|
||
there's no candidate. */
|
||
buf_len = min (bpaddr - boundary, MAX_IT_BLOCK_PREFIX);
|
||
if (buf_len == 0)
|
||
/* No room for an IT instruction. */
|
||
return bpaddr;
|
||
|
||
buf = xmalloc (buf_len);
|
||
if (target_read_memory (bpaddr - buf_len, buf, buf_len) != 0)
|
||
return bpaddr;
|
||
any = 0;
|
||
for (i = 0; i < buf_len; i += 2)
|
||
{
|
||
unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
|
||
if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
|
||
{
|
||
any = 1;
|
||
break;
|
||
}
|
||
}
|
||
if (any == 0)
|
||
{
|
||
xfree (buf);
|
||
return bpaddr;
|
||
}
|
||
|
||
/* OK, the code bytes before this instruction contain at least one
|
||
halfword which resembles an IT instruction. We know that it's
|
||
Thumb code, but there are still two possibilities. Either the
|
||
halfword really is an IT instruction, or it is the second half of
|
||
a 32-bit Thumb instruction. The only way we can tell is to
|
||
scan forwards from a known instruction boundary. */
|
||
if (bpaddr - boundary > IT_SCAN_THRESHOLD)
|
||
{
|
||
int definite;
|
||
|
||
/* There's a lot of code before this instruction. Start with an
|
||
optimistic search; it's easy to recognize halfwords that can
|
||
not be the start of a 32-bit instruction, and use that to
|
||
lock on to the instruction boundaries. */
|
||
buf = extend_buffer_earlier (buf, bpaddr, buf_len, IT_SCAN_THRESHOLD);
|
||
if (buf == NULL)
|
||
return bpaddr;
|
||
buf_len = IT_SCAN_THRESHOLD;
|
||
|
||
definite = 0;
|
||
for (i = 0; i < buf_len - sizeof (buf) && ! definite; i += 2)
|
||
{
|
||
unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
|
||
if (thumb_insn_size (inst1) == 2)
|
||
{
|
||
definite = 1;
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* At this point, if DEFINITE, BUF[I] is the first place we
|
||
are sure that we know the instruction boundaries, and it is far
|
||
enough from BPADDR that we could not miss an IT instruction
|
||
affecting BPADDR. If ! DEFINITE, give up - start from a
|
||
known boundary. */
|
||
if (! definite)
|
||
{
|
||
buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary);
|
||
if (buf == NULL)
|
||
return bpaddr;
|
||
buf_len = bpaddr - boundary;
|
||
i = 0;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary);
|
||
if (buf == NULL)
|
||
return bpaddr;
|
||
buf_len = bpaddr - boundary;
|
||
i = 0;
|
||
}
|
||
|
||
/* Scan forwards. Find the last IT instruction before BPADDR. */
|
||
last_it = -1;
|
||
last_it_count = 0;
|
||
while (i < buf_len)
|
||
{
|
||
unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
|
||
last_it_count--;
|
||
if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
|
||
{
|
||
last_it = i;
|
||
if (inst1 & 0x0001)
|
||
last_it_count = 4;
|
||
else if (inst1 & 0x0002)
|
||
last_it_count = 3;
|
||
else if (inst1 & 0x0004)
|
||
last_it_count = 2;
|
||
else
|
||
last_it_count = 1;
|
||
}
|
||
i += thumb_insn_size (inst1);
|
||
}
|
||
|
||
xfree (buf);
|
||
|
||
if (last_it == -1)
|
||
/* There wasn't really an IT instruction after all. */
|
||
return bpaddr;
|
||
|
||
if (last_it_count < 1)
|
||
/* It was too far away. */
|
||
return bpaddr;
|
||
|
||
/* This really is a trouble spot. Move the breakpoint to the IT
|
||
instruction. */
|
||
return bpaddr - buf_len + last_it;
|
||
}
|
||
|
||
/* ARM displaced stepping support.
|
||
|
||
Generally ARM displaced stepping works as follows:
|
||
|
||
1. When an instruction is to be single-stepped, it is first decoded by
|
||
arm_process_displaced_insn (called from arm_displaced_step_copy_insn).
|
||
Depending on the type of instruction, it is then copied to a scratch
|
||
location, possibly in a modified form. The copy_* set of functions
|
||
performs such modification, as necessary. A breakpoint is placed after
|
||
the modified instruction in the scratch space to return control to GDB.
|
||
Note in particular that instructions which modify the PC will no longer
|
||
do so after modification.
|
||
|
||
2. The instruction is single-stepped, by setting the PC to the scratch
|
||
location address, and resuming. Control returns to GDB when the
|
||
breakpoint is hit.
|
||
|
||
3. A cleanup function (cleanup_*) is called corresponding to the copy_*
|
||
function used for the current instruction. This function's job is to
|
||
put the CPU/memory state back to what it would have been if the
|
||
instruction had been executed unmodified in its original location. */
|
||
|
||
/* NOP instruction (mov r0, r0). */
|
||
#define ARM_NOP 0xe1a00000
|
||
|
||
/* Helper for register reads for displaced stepping. In particular, this
|
||
returns the PC as it would be seen by the instruction at its original
|
||
location. */
|
||
|
||
ULONGEST
|
||
displaced_read_reg (struct regcache *regs, CORE_ADDR from, int regno)
|
||
{
|
||
ULONGEST ret;
|
||
|
||
if (regno == 15)
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: read pc value %.8lx\n",
|
||
(unsigned long) from + 8);
|
||
return (ULONGEST) from + 8; /* Pipeline offset. */
|
||
}
|
||
else
|
||
{
|
||
regcache_cooked_read_unsigned (regs, regno, &ret);
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: read r%d value %.8lx\n",
|
||
regno, (unsigned long) ret);
|
||
return ret;
|
||
}
|
||
}
|
||
|
||
static int
|
||
displaced_in_arm_mode (struct regcache *regs)
|
||
{
|
||
ULONGEST ps;
|
||
|
||
regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
|
||
|
||
return (ps & CPSR_T) == 0;
|
||
}
|
||
|
||
/* Write to the PC as from a branch instruction. */
|
||
|
||
static void
|
||
branch_write_pc (struct regcache *regs, ULONGEST val)
|
||
{
|
||
if (displaced_in_arm_mode (regs))
|
||
/* Note: If bits 0/1 are set, this branch would be unpredictable for
|
||
architecture versions < 6. */
|
||
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & ~(ULONGEST) 0x3);
|
||
else
|
||
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & ~(ULONGEST) 0x1);
|
||
}
|
||
|
||
/* Write to the PC as from a branch-exchange instruction. */
|
||
|
||
static void
|
||
bx_write_pc (struct regcache *regs, ULONGEST val)
|
||
{
|
||
ULONGEST ps;
|
||
|
||
regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
|
||
|
||
if ((val & 1) == 1)
|
||
{
|
||
regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps | CPSR_T);
|
||
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffe);
|
||
}
|
||
else if ((val & 2) == 0)
|
||
{
|
||
regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM,
|
||
ps & ~(ULONGEST) CPSR_T);
|
||
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val);
|
||
}
|
||
else
|
||
{
|
||
/* Unpredictable behaviour. Try to do something sensible (switch to ARM
|
||
mode, align dest to 4 bytes). */
|
||
warning (_("Single-stepping BX to non-word-aligned ARM instruction."));
|
||
regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM,
|
||
ps & ~(ULONGEST) CPSR_T);
|
||
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffc);
|
||
}
|
||
}
|
||
|
||
/* Write to the PC as if from a load instruction. */
|
||
|
||
static void
|
||
load_write_pc (struct regcache *regs, ULONGEST val)
|
||
{
|
||
if (DISPLACED_STEPPING_ARCH_VERSION >= 5)
|
||
bx_write_pc (regs, val);
|
||
else
|
||
branch_write_pc (regs, val);
|
||
}
|
||
|
||
/* Write to the PC as if from an ALU instruction. */
|
||
|
||
static void
|
||
alu_write_pc (struct regcache *regs, ULONGEST val)
|
||
{
|
||
if (DISPLACED_STEPPING_ARCH_VERSION >= 7 && displaced_in_arm_mode (regs))
|
||
bx_write_pc (regs, val);
|
||
else
|
||
branch_write_pc (regs, val);
|
||
}
|
||
|
||
/* Helper for writing to registers for displaced stepping. Writing to the PC
|
||
has a varying effects depending on the instruction which does the write:
|
||
this is controlled by the WRITE_PC argument. */
|
||
|
||
void
|
||
displaced_write_reg (struct regcache *regs, struct displaced_step_closure *dsc,
|
||
int regno, ULONGEST val, enum pc_write_style write_pc)
|
||
{
|
||
if (regno == 15)
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: writing pc %.8lx\n",
|
||
(unsigned long) val);
|
||
switch (write_pc)
|
||
{
|
||
case BRANCH_WRITE_PC:
|
||
branch_write_pc (regs, val);
|
||
break;
|
||
|
||
case BX_WRITE_PC:
|
||
bx_write_pc (regs, val);
|
||
break;
|
||
|
||
case LOAD_WRITE_PC:
|
||
load_write_pc (regs, val);
|
||
break;
|
||
|
||
case ALU_WRITE_PC:
|
||
alu_write_pc (regs, val);
|
||
break;
|
||
|
||
case CANNOT_WRITE_PC:
|
||
warning (_("Instruction wrote to PC in an unexpected way when "
|
||
"single-stepping"));
|
||
break;
|
||
|
||
default:
|
||
internal_error (__FILE__, __LINE__,
|
||
_("Invalid argument to displaced_write_reg"));
|
||
}
|
||
|
||
dsc->wrote_to_pc = 1;
|
||
}
|
||
else
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: writing r%d value %.8lx\n",
|
||
regno, (unsigned long) val);
|
||
regcache_cooked_write_unsigned (regs, regno, val);
|
||
}
|
||
}
|
||
|
||
/* This function is used to concisely determine if an instruction INSN
|
||
references PC. Register fields of interest in INSN should have the
|
||
corresponding fields of BITMASK set to 0b1111. The function returns return 1
|
||
if any of these fields in INSN reference the PC (also 0b1111, r15), else it
|
||
returns 0. */
|
||
|
||
static int
|
||
insn_references_pc (uint32_t insn, uint32_t bitmask)
|
||
{
|
||
uint32_t lowbit = 1;
|
||
|
||
while (bitmask != 0)
|
||
{
|
||
uint32_t mask;
|
||
|
||
for (; lowbit && (bitmask & lowbit) == 0; lowbit <<= 1)
|
||
;
|
||
|
||
if (!lowbit)
|
||
break;
|
||
|
||
mask = lowbit * 0xf;
|
||
|
||
if ((insn & mask) == mask)
|
||
return 1;
|
||
|
||
bitmask &= ~mask;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* The simplest copy function. Many instructions have the same effect no
|
||
matter what address they are executed at: in those cases, use this. */
|
||
|
||
static int
|
||
copy_unmodified (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
|
||
const char *iname, struct displaced_step_closure *dsc)
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying insn %.8lx, "
|
||
"opcode/class '%s' unmodified\n", (unsigned long) insn,
|
||
iname);
|
||
|
||
dsc->modinsn[0] = insn;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Preload instructions with immediate offset. */
|
||
|
||
static void
|
||
cleanup_preload (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
|
||
if (!dsc->u.preload.immed)
|
||
displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
|
||
}
|
||
|
||
static int
|
||
copy_preload (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
ULONGEST rn_val;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (!insn_references_pc (insn, 0x000f0000ul))
|
||
return copy_unmodified (gdbarch, insn, "preload", dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying preload insn %.8lx\n",
|
||
(unsigned long) insn);
|
||
|
||
/* Preload instructions:
|
||
|
||
{pli/pld} [rn, #+/-imm]
|
||
->
|
||
{pli/pld} [r0, #+/-imm]. */
|
||
|
||
dsc->tmp[0] = displaced_read_reg (regs, from, 0);
|
||
rn_val = displaced_read_reg (regs, from, rn);
|
||
displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
|
||
|
||
dsc->u.preload.immed = 1;
|
||
|
||
dsc->modinsn[0] = insn & 0xfff0ffff;
|
||
|
||
dsc->cleanup = &cleanup_preload;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Preload instructions with register offset. */
|
||
|
||
static int
|
||
copy_preload_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
unsigned int rm = bits (insn, 0, 3);
|
||
ULONGEST rn_val, rm_val;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (!insn_references_pc (insn, 0x000f000ful))
|
||
return copy_unmodified (gdbarch, insn, "preload reg", dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying preload insn %.8lx\n",
|
||
(unsigned long) insn);
|
||
|
||
/* Preload register-offset instructions:
|
||
|
||
{pli/pld} [rn, rm {, shift}]
|
||
->
|
||
{pli/pld} [r0, r1 {, shift}]. */
|
||
|
||
dsc->tmp[0] = displaced_read_reg (regs, from, 0);
|
||
dsc->tmp[1] = displaced_read_reg (regs, from, 1);
|
||
rn_val = displaced_read_reg (regs, from, rn);
|
||
rm_val = displaced_read_reg (regs, from, rm);
|
||
displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 1, rm_val, CANNOT_WRITE_PC);
|
||
|
||
dsc->u.preload.immed = 0;
|
||
|
||
dsc->modinsn[0] = (insn & 0xfff0fff0) | 0x1;
|
||
|
||
dsc->cleanup = &cleanup_preload;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Copy/cleanup coprocessor load and store instructions. */
|
||
|
||
static void
|
||
cleanup_copro_load_store (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
|
||
struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST rn_val = displaced_read_reg (regs, dsc->insn_addr, 0);
|
||
|
||
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
|
||
|
||
if (dsc->u.ldst.writeback)
|
||
displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, LOAD_WRITE_PC);
|
||
}
|
||
|
||
static int
|
||
copy_copro_load_store (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
ULONGEST rn_val;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (!insn_references_pc (insn, 0x000f0000ul))
|
||
return copy_unmodified (gdbarch, insn, "copro load/store", dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying coprocessor "
|
||
"load/store insn %.8lx\n", (unsigned long) insn);
|
||
|
||
/* Coprocessor load/store instructions:
|
||
|
||
{stc/stc2} [<Rn>, #+/-imm] (and other immediate addressing modes)
|
||
->
|
||
{stc/stc2} [r0, #+/-imm].
|
||
|
||
ldc/ldc2 are handled identically. */
|
||
|
||
dsc->tmp[0] = displaced_read_reg (regs, from, 0);
|
||
rn_val = displaced_read_reg (regs, from, rn);
|
||
displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
|
||
|
||
dsc->u.ldst.writeback = bit (insn, 25);
|
||
dsc->u.ldst.rn = rn;
|
||
|
||
dsc->modinsn[0] = insn & 0xfff0ffff;
|
||
|
||
dsc->cleanup = &cleanup_copro_load_store;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Clean up branch instructions (actually perform the branch, by setting
|
||
PC). */
|
||
|
||
static void
|
||
cleanup_branch (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST from = dsc->insn_addr;
|
||
uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
|
||
int branch_taken = condition_true (dsc->u.branch.cond, status);
|
||
enum pc_write_style write_pc = dsc->u.branch.exchange
|
||
? BX_WRITE_PC : BRANCH_WRITE_PC;
|
||
|
||
if (!branch_taken)
|
||
return;
|
||
|
||
if (dsc->u.branch.link)
|
||
{
|
||
ULONGEST pc = displaced_read_reg (regs, from, 15);
|
||
displaced_write_reg (regs, dsc, 14, pc - 4, CANNOT_WRITE_PC);
|
||
}
|
||
|
||
displaced_write_reg (regs, dsc, 15, dsc->u.branch.dest, write_pc);
|
||
}
|
||
|
||
/* Copy B/BL/BLX instructions with immediate destinations. */
|
||
|
||
static int
|
||
copy_b_bl_blx (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int cond = bits (insn, 28, 31);
|
||
int exchange = (cond == 0xf);
|
||
int link = exchange || bit (insn, 24);
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
long offset;
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying %s immediate insn "
|
||
"%.8lx\n", (exchange) ? "blx" : (link) ? "bl" : "b",
|
||
(unsigned long) insn);
|
||
|
||
/* Implement "BL<cond> <label>" as:
|
||
|
||
Preparation: cond <- instruction condition
|
||
Insn: mov r0, r0 (nop)
|
||
Cleanup: if (condition true) { r14 <- pc; pc <- label }.
|
||
|
||
B<cond> similar, but don't set r14 in cleanup. */
|
||
|
||
if (exchange)
|
||
/* For BLX, set bit 0 of the destination. The cleanup_branch function will
|
||
then arrange the switch into Thumb mode. */
|
||
offset = (bits (insn, 0, 23) << 2) | (bit (insn, 24) << 1) | 1;
|
||
else
|
||
offset = bits (insn, 0, 23) << 2;
|
||
|
||
if (bit (offset, 25))
|
||
offset = offset | ~0x3ffffff;
|
||
|
||
dsc->u.branch.cond = cond;
|
||
dsc->u.branch.link = link;
|
||
dsc->u.branch.exchange = exchange;
|
||
dsc->u.branch.dest = from + 8 + offset;
|
||
|
||
dsc->modinsn[0] = ARM_NOP;
|
||
|
||
dsc->cleanup = &cleanup_branch;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Copy BX/BLX with register-specified destinations. */
|
||
|
||
static int
|
||
copy_bx_blx_reg (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int cond = bits (insn, 28, 31);
|
||
/* BX: x12xxx1x
|
||
BLX: x12xxx3x. */
|
||
int link = bit (insn, 5);
|
||
unsigned int rm = bits (insn, 0, 3);
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying %s register insn "
|
||
"%.8lx\n", (link) ? "blx" : "bx", (unsigned long) insn);
|
||
|
||
/* Implement {BX,BLX}<cond> <reg>" as:
|
||
|
||
Preparation: cond <- instruction condition
|
||
Insn: mov r0, r0 (nop)
|
||
Cleanup: if (condition true) { r14 <- pc; pc <- dest; }.
|
||
|
||
Don't set r14 in cleanup for BX. */
|
||
|
||
dsc->u.branch.dest = displaced_read_reg (regs, from, rm);
|
||
|
||
dsc->u.branch.cond = cond;
|
||
dsc->u.branch.link = link;
|
||
dsc->u.branch.exchange = 1;
|
||
|
||
dsc->modinsn[0] = ARM_NOP;
|
||
|
||
dsc->cleanup = &cleanup_branch;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Copy/cleanup arithmetic/logic instruction with immediate RHS. */
|
||
|
||
static void
|
||
cleanup_alu_imm (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
|
||
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
|
||
}
|
||
|
||
static int
|
||
copy_alu_imm (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
unsigned int rd = bits (insn, 12, 15);
|
||
unsigned int op = bits (insn, 21, 24);
|
||
int is_mov = (op == 0xd);
|
||
ULONGEST rd_val, rn_val;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (!insn_references_pc (insn, 0x000ff000ul))
|
||
return copy_unmodified (gdbarch, insn, "ALU immediate", dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying immediate %s insn "
|
||
"%.8lx\n", is_mov ? "move" : "ALU",
|
||
(unsigned long) insn);
|
||
|
||
/* Instruction is of form:
|
||
|
||
<op><cond> rd, [rn,] #imm
|
||
|
||
Rewrite as:
|
||
|
||
Preparation: tmp1, tmp2 <- r0, r1;
|
||
r0, r1 <- rd, rn
|
||
Insn: <op><cond> r0, r1, #imm
|
||
Cleanup: rd <- r0; r0 <- tmp1; r1 <- tmp2
|
||
*/
|
||
|
||
dsc->tmp[0] = displaced_read_reg (regs, from, 0);
|
||
dsc->tmp[1] = displaced_read_reg (regs, from, 1);
|
||
rn_val = displaced_read_reg (regs, from, rn);
|
||
rd_val = displaced_read_reg (regs, from, rd);
|
||
displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
|
||
dsc->rd = rd;
|
||
|
||
if (is_mov)
|
||
dsc->modinsn[0] = insn & 0xfff00fff;
|
||
else
|
||
dsc->modinsn[0] = (insn & 0xfff00fff) | 0x10000;
|
||
|
||
dsc->cleanup = &cleanup_alu_imm;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Copy/cleanup arithmetic/logic insns with register RHS. */
|
||
|
||
static void
|
||
cleanup_alu_reg (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST rd_val;
|
||
int i;
|
||
|
||
rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
|
||
|
||
for (i = 0; i < 3; i++)
|
||
displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
|
||
|
||
displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
|
||
}
|
||
|
||
static int
|
||
copy_alu_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
unsigned int rm = bits (insn, 0, 3);
|
||
unsigned int rd = bits (insn, 12, 15);
|
||
unsigned int op = bits (insn, 21, 24);
|
||
int is_mov = (op == 0xd);
|
||
ULONGEST rd_val, rn_val, rm_val;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (!insn_references_pc (insn, 0x000ff00ful))
|
||
return copy_unmodified (gdbarch, insn, "ALU reg", dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying reg %s insn %.8lx\n",
|
||
is_mov ? "move" : "ALU", (unsigned long) insn);
|
||
|
||
/* Instruction is of form:
|
||
|
||
<op><cond> rd, [rn,] rm [, <shift>]
|
||
|
||
Rewrite as:
|
||
|
||
Preparation: tmp1, tmp2, tmp3 <- r0, r1, r2;
|
||
r0, r1, r2 <- rd, rn, rm
|
||
Insn: <op><cond> r0, r1, r2 [, <shift>]
|
||
Cleanup: rd <- r0; r0, r1, r2 <- tmp1, tmp2, tmp3
|
||
*/
|
||
|
||
dsc->tmp[0] = displaced_read_reg (regs, from, 0);
|
||
dsc->tmp[1] = displaced_read_reg (regs, from, 1);
|
||
dsc->tmp[2] = displaced_read_reg (regs, from, 2);
|
||
rd_val = displaced_read_reg (regs, from, rd);
|
||
rn_val = displaced_read_reg (regs, from, rn);
|
||
rm_val = displaced_read_reg (regs, from, rm);
|
||
displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
|
||
dsc->rd = rd;
|
||
|
||
if (is_mov)
|
||
dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x2;
|
||
else
|
||
dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x10002;
|
||
|
||
dsc->cleanup = &cleanup_alu_reg;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Cleanup/copy arithmetic/logic insns with shifted register RHS. */
|
||
|
||
static void
|
||
cleanup_alu_shifted_reg (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
|
||
struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
|
||
int i;
|
||
|
||
for (i = 0; i < 4; i++)
|
||
displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
|
||
|
||
displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
|
||
}
|
||
|
||
static int
|
||
copy_alu_shifted_reg (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
unsigned int rm = bits (insn, 0, 3);
|
||
unsigned int rd = bits (insn, 12, 15);
|
||
unsigned int rs = bits (insn, 8, 11);
|
||
unsigned int op = bits (insn, 21, 24);
|
||
int is_mov = (op == 0xd), i;
|
||
ULONGEST rd_val, rn_val, rm_val, rs_val;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (!insn_references_pc (insn, 0x000fff0ful))
|
||
return copy_unmodified (gdbarch, insn, "ALU shifted reg", dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying shifted reg %s insn "
|
||
"%.8lx\n", is_mov ? "move" : "ALU",
|
||
(unsigned long) insn);
|
||
|
||
/* Instruction is of form:
|
||
|
||
<op><cond> rd, [rn,] rm, <shift> rs
|
||
|
||
Rewrite as:
|
||
|
||
Preparation: tmp1, tmp2, tmp3, tmp4 <- r0, r1, r2, r3
|
||
r0, r1, r2, r3 <- rd, rn, rm, rs
|
||
Insn: <op><cond> r0, r1, r2, <shift> r3
|
||
Cleanup: tmp5 <- r0
|
||
r0, r1, r2, r3 <- tmp1, tmp2, tmp3, tmp4
|
||
rd <- tmp5
|
||
*/
|
||
|
||
for (i = 0; i < 4; i++)
|
||
dsc->tmp[i] = displaced_read_reg (regs, from, i);
|
||
|
||
rd_val = displaced_read_reg (regs, from, rd);
|
||
rn_val = displaced_read_reg (regs, from, rn);
|
||
rm_val = displaced_read_reg (regs, from, rm);
|
||
rs_val = displaced_read_reg (regs, from, rs);
|
||
displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 3, rs_val, CANNOT_WRITE_PC);
|
||
dsc->rd = rd;
|
||
|
||
if (is_mov)
|
||
dsc->modinsn[0] = (insn & 0xfff000f0) | 0x302;
|
||
else
|
||
dsc->modinsn[0] = (insn & 0xfff000f0) | 0x10302;
|
||
|
||
dsc->cleanup = &cleanup_alu_shifted_reg;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Clean up load instructions. */
|
||
|
||
static void
|
||
cleanup_load (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST rt_val, rt_val2 = 0, rn_val;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
rt_val = displaced_read_reg (regs, from, 0);
|
||
if (dsc->u.ldst.xfersize == 8)
|
||
rt_val2 = displaced_read_reg (regs, from, 1);
|
||
rn_val = displaced_read_reg (regs, from, 2);
|
||
|
||
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
|
||
if (dsc->u.ldst.xfersize > 4)
|
||
displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC);
|
||
if (!dsc->u.ldst.immed)
|
||
displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC);
|
||
|
||
/* Handle register writeback. */
|
||
if (dsc->u.ldst.writeback)
|
||
displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC);
|
||
/* Put result in right place. */
|
||
displaced_write_reg (regs, dsc, dsc->rd, rt_val, LOAD_WRITE_PC);
|
||
if (dsc->u.ldst.xfersize == 8)
|
||
displaced_write_reg (regs, dsc, dsc->rd + 1, rt_val2, LOAD_WRITE_PC);
|
||
}
|
||
|
||
/* Clean up store instructions. */
|
||
|
||
static void
|
||
cleanup_store (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
ULONGEST rn_val = displaced_read_reg (regs, from, 2);
|
||
|
||
displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
|
||
if (dsc->u.ldst.xfersize > 4)
|
||
displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC);
|
||
if (!dsc->u.ldst.immed)
|
||
displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC);
|
||
if (!dsc->u.ldst.restore_r4)
|
||
displaced_write_reg (regs, dsc, 4, dsc->tmp[4], CANNOT_WRITE_PC);
|
||
|
||
/* Writeback. */
|
||
if (dsc->u.ldst.writeback)
|
||
displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC);
|
||
}
|
||
|
||
/* Copy "extra" load/store instructions. These are halfword/doubleword
|
||
transfers, which have a different encoding to byte/word transfers. */
|
||
|
||
static int
|
||
copy_extra_ld_st (struct gdbarch *gdbarch, uint32_t insn, int unpriveleged,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int op1 = bits (insn, 20, 24);
|
||
unsigned int op2 = bits (insn, 5, 6);
|
||
unsigned int rt = bits (insn, 12, 15);
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
unsigned int rm = bits (insn, 0, 3);
|
||
char load[12] = {0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1};
|
||
char bytesize[12] = {2, 2, 2, 2, 8, 1, 8, 1, 8, 2, 8, 2};
|
||
int immed = (op1 & 0x4) != 0;
|
||
int opcode;
|
||
ULONGEST rt_val, rt_val2 = 0, rn_val, rm_val = 0;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (!insn_references_pc (insn, 0x000ff00ful))
|
||
return copy_unmodified (gdbarch, insn, "extra load/store", dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying %sextra load/store "
|
||
"insn %.8lx\n", unpriveleged ? "unpriveleged " : "",
|
||
(unsigned long) insn);
|
||
|
||
opcode = ((op2 << 2) | (op1 & 0x1) | ((op1 & 0x4) >> 1)) - 4;
|
||
|
||
if (opcode < 0)
|
||
internal_error (__FILE__, __LINE__,
|
||
_("copy_extra_ld_st: instruction decode error"));
|
||
|
||
dsc->tmp[0] = displaced_read_reg (regs, from, 0);
|
||
dsc->tmp[1] = displaced_read_reg (regs, from, 1);
|
||
dsc->tmp[2] = displaced_read_reg (regs, from, 2);
|
||
if (!immed)
|
||
dsc->tmp[3] = displaced_read_reg (regs, from, 3);
|
||
|
||
rt_val = displaced_read_reg (regs, from, rt);
|
||
if (bytesize[opcode] == 8)
|
||
rt_val2 = displaced_read_reg (regs, from, rt + 1);
|
||
rn_val = displaced_read_reg (regs, from, rn);
|
||
if (!immed)
|
||
rm_val = displaced_read_reg (regs, from, rm);
|
||
|
||
displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
|
||
if (bytesize[opcode] == 8)
|
||
displaced_write_reg (regs, dsc, 1, rt_val2, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
|
||
if (!immed)
|
||
displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC);
|
||
|
||
dsc->rd = rt;
|
||
dsc->u.ldst.xfersize = bytesize[opcode];
|
||
dsc->u.ldst.rn = rn;
|
||
dsc->u.ldst.immed = immed;
|
||
dsc->u.ldst.writeback = bit (insn, 24) == 0 || bit (insn, 21) != 0;
|
||
dsc->u.ldst.restore_r4 = 0;
|
||
|
||
if (immed)
|
||
/* {ldr,str}<width><cond> rt, [rt2,] [rn, #imm]
|
||
->
|
||
{ldr,str}<width><cond> r0, [r1,] [r2, #imm]. */
|
||
dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000;
|
||
else
|
||
/* {ldr,str}<width><cond> rt, [rt2,] [rn, +/-rm]
|
||
->
|
||
{ldr,str}<width><cond> r0, [r1,] [r2, +/-r3]. */
|
||
dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003;
|
||
|
||
dsc->cleanup = load[opcode] ? &cleanup_load : &cleanup_store;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Copy byte/word loads and stores. */
|
||
|
||
static int
|
||
copy_ldr_str_ldrb_strb (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct regcache *regs,
|
||
struct displaced_step_closure *dsc, int load, int byte,
|
||
int usermode)
|
||
{
|
||
int immed = !bit (insn, 25);
|
||
unsigned int rt = bits (insn, 12, 15);
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
unsigned int rm = bits (insn, 0, 3); /* Only valid if !immed. */
|
||
ULONGEST rt_val, rn_val, rm_val = 0;
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
if (!insn_references_pc (insn, 0x000ff00ful))
|
||
return copy_unmodified (gdbarch, insn, "load/store", dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying %s%s insn %.8lx\n",
|
||
load ? (byte ? "ldrb" : "ldr")
|
||
: (byte ? "strb" : "str"), usermode ? "t" : "",
|
||
(unsigned long) insn);
|
||
|
||
dsc->tmp[0] = displaced_read_reg (regs, from, 0);
|
||
dsc->tmp[2] = displaced_read_reg (regs, from, 2);
|
||
if (!immed)
|
||
dsc->tmp[3] = displaced_read_reg (regs, from, 3);
|
||
if (!load)
|
||
dsc->tmp[4] = displaced_read_reg (regs, from, 4);
|
||
|
||
rt_val = displaced_read_reg (regs, from, rt);
|
||
rn_val = displaced_read_reg (regs, from, rn);
|
||
if (!immed)
|
||
rm_val = displaced_read_reg (regs, from, rm);
|
||
|
||
displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
|
||
displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
|
||
if (!immed)
|
||
displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC);
|
||
|
||
dsc->rd = rt;
|
||
dsc->u.ldst.xfersize = byte ? 1 : 4;
|
||
dsc->u.ldst.rn = rn;
|
||
dsc->u.ldst.immed = immed;
|
||
dsc->u.ldst.writeback = bit (insn, 24) == 0 || bit (insn, 21) != 0;
|
||
|
||
/* To write PC we can do:
|
||
|
||
scratch+0: str pc, temp (*temp = scratch + 8 + offset)
|
||
scratch+4: ldr r4, temp
|
||
scratch+8: sub r4, r4, pc (r4 = scratch + 8 + offset - scratch - 8 - 8)
|
||
scratch+12: add r4, r4, #8 (r4 = offset)
|
||
scratch+16: add r0, r0, r4
|
||
scratch+20: str r0, [r2, #imm] (or str r0, [r2, r3])
|
||
scratch+24: <temp>
|
||
|
||
Otherwise we don't know what value to write for PC, since the offset is
|
||
architecture-dependent (sometimes PC+8, sometimes PC+12). */
|
||
|
||
if (load || rt != 15)
|
||
{
|
||
dsc->u.ldst.restore_r4 = 0;
|
||
|
||
if (immed)
|
||
/* {ldr,str}[b]<cond> rt, [rn, #imm], etc.
|
||
->
|
||
{ldr,str}[b]<cond> r0, [r2, #imm]. */
|
||
dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000;
|
||
else
|
||
/* {ldr,str}[b]<cond> rt, [rn, rm], etc.
|
||
->
|
||
{ldr,str}[b]<cond> r0, [r2, r3]. */
|
||
dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003;
|
||
}
|
||
else
|
||
{
|
||
/* We need to use r4 as scratch. Make sure it's restored afterwards. */
|
||
dsc->u.ldst.restore_r4 = 1;
|
||
|
||
dsc->modinsn[0] = 0xe58ff014; /* str pc, [pc, #20]. */
|
||
dsc->modinsn[1] = 0xe59f4010; /* ldr r4, [pc, #16]. */
|
||
dsc->modinsn[2] = 0xe044400f; /* sub r4, r4, pc. */
|
||
dsc->modinsn[3] = 0xe2844008; /* add r4, r4, #8. */
|
||
dsc->modinsn[4] = 0xe0800004; /* add r0, r0, r4. */
|
||
|
||
/* As above. */
|
||
if (immed)
|
||
dsc->modinsn[5] = (insn & 0xfff00fff) | 0x20000;
|
||
else
|
||
dsc->modinsn[5] = (insn & 0xfff00ff0) | 0x20003;
|
||
|
||
dsc->modinsn[6] = 0x0; /* breakpoint location. */
|
||
dsc->modinsn[7] = 0x0; /* scratch space. */
|
||
|
||
dsc->numinsns = 6;
|
||
}
|
||
|
||
dsc->cleanup = load ? &cleanup_load : &cleanup_store;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Cleanup LDM instructions with fully-populated register list. This is an
|
||
unfortunate corner case: it's impossible to implement correctly by modifying
|
||
the instruction. The issue is as follows: we have an instruction,
|
||
|
||
ldm rN, {r0-r15}
|
||
|
||
which we must rewrite to avoid loading PC. A possible solution would be to
|
||
do the load in two halves, something like (with suitable cleanup
|
||
afterwards):
|
||
|
||
mov r8, rN
|
||
ldm[id][ab] r8!, {r0-r7}
|
||
str r7, <temp>
|
||
ldm[id][ab] r8, {r7-r14}
|
||
<bkpt>
|
||
|
||
but at present there's no suitable place for <temp>, since the scratch space
|
||
is overwritten before the cleanup routine is called. For now, we simply
|
||
emulate the instruction. */
|
||
|
||
static void
|
||
cleanup_block_load_all (struct gdbarch *gdbarch, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST from = dsc->insn_addr;
|
||
int inc = dsc->u.block.increment;
|
||
int bump_before = dsc->u.block.before ? (inc ? 4 : -4) : 0;
|
||
int bump_after = dsc->u.block.before ? 0 : (inc ? 4 : -4);
|
||
uint32_t regmask = dsc->u.block.regmask;
|
||
int regno = inc ? 0 : 15;
|
||
CORE_ADDR xfer_addr = dsc->u.block.xfer_addr;
|
||
int exception_return = dsc->u.block.load && dsc->u.block.user
|
||
&& (regmask & 0x8000) != 0;
|
||
uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
|
||
int do_transfer = condition_true (dsc->u.block.cond, status);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
|
||
if (!do_transfer)
|
||
return;
|
||
|
||
/* If the instruction is ldm rN, {...pc}^, I don't think there's anything
|
||
sensible we can do here. Complain loudly. */
|
||
if (exception_return)
|
||
error (_("Cannot single-step exception return"));
|
||
|
||
/* We don't handle any stores here for now. */
|
||
gdb_assert (dsc->u.block.load != 0);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: emulating block transfer: "
|
||
"%s %s %s\n", dsc->u.block.load ? "ldm" : "stm",
|
||
dsc->u.block.increment ? "inc" : "dec",
|
||
dsc->u.block.before ? "before" : "after");
|
||
|
||
while (regmask)
|
||
{
|
||
uint32_t memword;
|
||
|
||
if (inc)
|
||
while (regno <= 15 && (regmask & (1 << regno)) == 0)
|
||
regno++;
|
||
else
|
||
while (regno >= 0 && (regmask & (1 << regno)) == 0)
|
||
regno--;
|
||
|
||
xfer_addr += bump_before;
|
||
|
||
memword = read_memory_unsigned_integer (xfer_addr, 4, byte_order);
|
||
displaced_write_reg (regs, dsc, regno, memword, LOAD_WRITE_PC);
|
||
|
||
xfer_addr += bump_after;
|
||
|
||
regmask &= ~(1 << regno);
|
||
}
|
||
|
||
if (dsc->u.block.writeback)
|
||
displaced_write_reg (regs, dsc, dsc->u.block.rn, xfer_addr,
|
||
CANNOT_WRITE_PC);
|
||
}
|
||
|
||
/* Clean up an STM which included the PC in the register list. */
|
||
|
||
static void
|
||
cleanup_block_store_pc (struct gdbarch *gdbarch, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST from = dsc->insn_addr;
|
||
uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
|
||
int store_executed = condition_true (dsc->u.block.cond, status);
|
||
CORE_ADDR pc_stored_at, transferred_regs = bitcount (dsc->u.block.regmask);
|
||
CORE_ADDR stm_insn_addr;
|
||
uint32_t pc_val;
|
||
long offset;
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
|
||
/* If condition code fails, there's nothing else to do. */
|
||
if (!store_executed)
|
||
return;
|
||
|
||
if (dsc->u.block.increment)
|
||
{
|
||
pc_stored_at = dsc->u.block.xfer_addr + 4 * transferred_regs;
|
||
|
||
if (dsc->u.block.before)
|
||
pc_stored_at += 4;
|
||
}
|
||
else
|
||
{
|
||
pc_stored_at = dsc->u.block.xfer_addr;
|
||
|
||
if (dsc->u.block.before)
|
||
pc_stored_at -= 4;
|
||
}
|
||
|
||
pc_val = read_memory_unsigned_integer (pc_stored_at, 4, byte_order);
|
||
stm_insn_addr = dsc->scratch_base;
|
||
offset = pc_val - stm_insn_addr;
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: detected PC offset %.8lx for "
|
||
"STM instruction\n", offset);
|
||
|
||
/* Rewrite the stored PC to the proper value for the non-displaced original
|
||
instruction. */
|
||
write_memory_unsigned_integer (pc_stored_at, 4, byte_order,
|
||
dsc->insn_addr + offset);
|
||
}
|
||
|
||
/* Clean up an LDM which includes the PC in the register list. We clumped all
|
||
the registers in the transferred list into a contiguous range r0...rX (to
|
||
avoid loading PC directly and losing control of the debugged program), so we
|
||
must undo that here. */
|
||
|
||
static void
|
||
cleanup_block_load_pc (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
|
||
struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
ULONGEST from = dsc->insn_addr;
|
||
uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
|
||
int load_executed = condition_true (dsc->u.block.cond, status), i;
|
||
unsigned int mask = dsc->u.block.regmask, write_reg = 15;
|
||
unsigned int regs_loaded = bitcount (mask);
|
||
unsigned int num_to_shuffle = regs_loaded, clobbered;
|
||
|
||
/* The method employed here will fail if the register list is fully populated
|
||
(we need to avoid loading PC directly). */
|
||
gdb_assert (num_to_shuffle < 16);
|
||
|
||
if (!load_executed)
|
||
return;
|
||
|
||
clobbered = (1 << num_to_shuffle) - 1;
|
||
|
||
while (num_to_shuffle > 0)
|
||
{
|
||
if ((mask & (1 << write_reg)) != 0)
|
||
{
|
||
unsigned int read_reg = num_to_shuffle - 1;
|
||
|
||
if (read_reg != write_reg)
|
||
{
|
||
ULONGEST rval = displaced_read_reg (regs, from, read_reg);
|
||
displaced_write_reg (regs, dsc, write_reg, rval, LOAD_WRITE_PC);
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: move "
|
||
"loaded register r%d to r%d\n"), read_reg,
|
||
write_reg);
|
||
}
|
||
else if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: register "
|
||
"r%d already in the right place\n"),
|
||
write_reg);
|
||
|
||
clobbered &= ~(1 << write_reg);
|
||
|
||
num_to_shuffle--;
|
||
}
|
||
|
||
write_reg--;
|
||
}
|
||
|
||
/* Restore any registers we scribbled over. */
|
||
for (write_reg = 0; clobbered != 0; write_reg++)
|
||
{
|
||
if ((clobbered & (1 << write_reg)) != 0)
|
||
{
|
||
displaced_write_reg (regs, dsc, write_reg, dsc->tmp[write_reg],
|
||
CANNOT_WRITE_PC);
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: restored "
|
||
"clobbered register r%d\n"), write_reg);
|
||
clobbered &= ~(1 << write_reg);
|
||
}
|
||
}
|
||
|
||
/* Perform register writeback manually. */
|
||
if (dsc->u.block.writeback)
|
||
{
|
||
ULONGEST new_rn_val = dsc->u.block.xfer_addr;
|
||
|
||
if (dsc->u.block.increment)
|
||
new_rn_val += regs_loaded * 4;
|
||
else
|
||
new_rn_val -= regs_loaded * 4;
|
||
|
||
displaced_write_reg (regs, dsc, dsc->u.block.rn, new_rn_val,
|
||
CANNOT_WRITE_PC);
|
||
}
|
||
}
|
||
|
||
/* Handle ldm/stm, apart from some tricky cases which are unlikely to occur
|
||
in user-level code (in particular exception return, ldm rn, {...pc}^). */
|
||
|
||
static int
|
||
copy_block_xfer (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
int load = bit (insn, 20);
|
||
int user = bit (insn, 22);
|
||
int increment = bit (insn, 23);
|
||
int before = bit (insn, 24);
|
||
int writeback = bit (insn, 21);
|
||
int rn = bits (insn, 16, 19);
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
/* Block transfers which don't mention PC can be run directly out-of-line. */
|
||
if (rn != 15 && (insn & 0x8000) == 0)
|
||
return copy_unmodified (gdbarch, insn, "ldm/stm", dsc);
|
||
|
||
if (rn == 15)
|
||
{
|
||
warning (_("displaced: Unpredictable LDM or STM with base register r15"));
|
||
return copy_unmodified (gdbarch, insn, "unpredictable ldm/stm", dsc);
|
||
}
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying block transfer insn "
|
||
"%.8lx\n", (unsigned long) insn);
|
||
|
||
dsc->u.block.xfer_addr = displaced_read_reg (regs, from, rn);
|
||
dsc->u.block.rn = rn;
|
||
|
||
dsc->u.block.load = load;
|
||
dsc->u.block.user = user;
|
||
dsc->u.block.increment = increment;
|
||
dsc->u.block.before = before;
|
||
dsc->u.block.writeback = writeback;
|
||
dsc->u.block.cond = bits (insn, 28, 31);
|
||
|
||
dsc->u.block.regmask = insn & 0xffff;
|
||
|
||
if (load)
|
||
{
|
||
if ((insn & 0xffff) == 0xffff)
|
||
{
|
||
/* LDM with a fully-populated register list. This case is
|
||
particularly tricky. Implement for now by fully emulating the
|
||
instruction (which might not behave perfectly in all cases, but
|
||
these instructions should be rare enough for that not to matter
|
||
too much). */
|
||
dsc->modinsn[0] = ARM_NOP;
|
||
|
||
dsc->cleanup = &cleanup_block_load_all;
|
||
}
|
||
else
|
||
{
|
||
/* LDM of a list of registers which includes PC. Implement by
|
||
rewriting the list of registers to be transferred into a
|
||
contiguous chunk r0...rX before doing the transfer, then shuffling
|
||
registers into the correct places in the cleanup routine. */
|
||
unsigned int regmask = insn & 0xffff;
|
||
unsigned int num_in_list = bitcount (regmask), new_regmask, bit = 1;
|
||
unsigned int to = 0, from = 0, i, new_rn;
|
||
|
||
for (i = 0; i < num_in_list; i++)
|
||
dsc->tmp[i] = displaced_read_reg (regs, from, i);
|
||
|
||
/* Writeback makes things complicated. We need to avoid clobbering
|
||
the base register with one of the registers in our modified
|
||
register list, but just using a different register can't work in
|
||
all cases, e.g.:
|
||
|
||
ldm r14!, {r0-r13,pc}
|
||
|
||
which would need to be rewritten as:
|
||
|
||
ldm rN!, {r0-r14}
|
||
|
||
but that can't work, because there's no free register for N.
|
||
|
||
Solve this by turning off the writeback bit, and emulating
|
||
writeback manually in the cleanup routine. */
|
||
|
||
if (writeback)
|
||
insn &= ~(1 << 21);
|
||
|
||
new_regmask = (1 << num_in_list) - 1;
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, _("displaced: LDM r%d%s, "
|
||
"{..., pc}: original reg list %.4x, modified "
|
||
"list %.4x\n"), rn, writeback ? "!" : "",
|
||
(int) insn & 0xffff, new_regmask);
|
||
|
||
dsc->modinsn[0] = (insn & ~0xffff) | (new_regmask & 0xffff);
|
||
|
||
dsc->cleanup = &cleanup_block_load_pc;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* STM of a list of registers which includes PC. Run the instruction
|
||
as-is, but out of line: this will store the wrong value for the PC,
|
||
so we must manually fix up the memory in the cleanup routine.
|
||
Doing things this way has the advantage that we can auto-detect
|
||
the offset of the PC write (which is architecture-dependent) in
|
||
the cleanup routine. */
|
||
dsc->modinsn[0] = insn;
|
||
|
||
dsc->cleanup = &cleanup_block_store_pc;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Cleanup/copy SVC (SWI) instructions. These two functions are overridden
|
||
for Linux, where some SVC instructions must be treated specially. */
|
||
|
||
static void
|
||
cleanup_svc (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
CORE_ADDR resume_addr = from + 4;
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: cleanup for svc, resume at "
|
||
"%.8lx\n", (unsigned long) resume_addr);
|
||
|
||
displaced_write_reg (regs, dsc, ARM_PC_REGNUM, resume_addr, BRANCH_WRITE_PC);
|
||
}
|
||
|
||
static int
|
||
copy_svc (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
CORE_ADDR from = dsc->insn_addr;
|
||
|
||
/* Allow OS-specific code to override SVC handling. */
|
||
if (dsc->u.svc.copy_svc_os)
|
||
return dsc->u.svc.copy_svc_os (gdbarch, insn, to, regs, dsc);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying svc insn %.8lx\n",
|
||
(unsigned long) insn);
|
||
|
||
/* Preparation: none.
|
||
Insn: unmodified svc.
|
||
Cleanup: pc <- insn_addr + 4. */
|
||
|
||
dsc->modinsn[0] = insn;
|
||
|
||
dsc->cleanup = &cleanup_svc;
|
||
/* Pretend we wrote to the PC, so cleanup doesn't set PC to the next
|
||
instruction. */
|
||
dsc->wrote_to_pc = 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Copy undefined instructions. */
|
||
|
||
static int
|
||
copy_undef (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying undefined insn %.8lx\n",
|
||
(unsigned long) insn);
|
||
|
||
dsc->modinsn[0] = insn;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Copy unpredictable instructions. */
|
||
|
||
static int
|
||
copy_unpred (struct gdbarch *gdbarch ATTRIBUTE_UNUSED, uint32_t insn,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copying unpredictable insn "
|
||
"%.8lx\n", (unsigned long) insn);
|
||
|
||
dsc->modinsn[0] = insn;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* The decode_* functions are instruction decoding helpers. They mostly follow
|
||
the presentation in the ARM ARM. */
|
||
|
||
static int
|
||
decode_misc_memhint_neon (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int op1 = bits (insn, 20, 26), op2 = bits (insn, 4, 7);
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
|
||
if (op1 == 0x10 && (op2 & 0x2) == 0x0 && (rn & 0xe) == 0x0)
|
||
return copy_unmodified (gdbarch, insn, "cps", dsc);
|
||
else if (op1 == 0x10 && op2 == 0x0 && (rn & 0xe) == 0x1)
|
||
return copy_unmodified (gdbarch, insn, "setend", dsc);
|
||
else if ((op1 & 0x60) == 0x20)
|
||
return copy_unmodified (gdbarch, insn, "neon dataproc", dsc);
|
||
else if ((op1 & 0x71) == 0x40)
|
||
return copy_unmodified (gdbarch, insn, "neon elt/struct load/store", dsc);
|
||
else if ((op1 & 0x77) == 0x41)
|
||
return copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc);
|
||
else if ((op1 & 0x77) == 0x45)
|
||
return copy_preload (gdbarch, insn, regs, dsc); /* pli. */
|
||
else if ((op1 & 0x77) == 0x51)
|
||
{
|
||
if (rn != 0xf)
|
||
return copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */
|
||
else
|
||
return copy_unpred (gdbarch, insn, dsc);
|
||
}
|
||
else if ((op1 & 0x77) == 0x55)
|
||
return copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */
|
||
else if (op1 == 0x57)
|
||
switch (op2)
|
||
{
|
||
case 0x1: return copy_unmodified (gdbarch, insn, "clrex", dsc);
|
||
case 0x4: return copy_unmodified (gdbarch, insn, "dsb", dsc);
|
||
case 0x5: return copy_unmodified (gdbarch, insn, "dmb", dsc);
|
||
case 0x6: return copy_unmodified (gdbarch, insn, "isb", dsc);
|
||
default: return copy_unpred (gdbarch, insn, dsc);
|
||
}
|
||
else if ((op1 & 0x63) == 0x43)
|
||
return copy_unpred (gdbarch, insn, dsc);
|
||
else if ((op2 & 0x1) == 0x0)
|
||
switch (op1 & ~0x80)
|
||
{
|
||
case 0x61:
|
||
return copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc);
|
||
case 0x65:
|
||
return copy_preload_reg (gdbarch, insn, regs, dsc); /* pli reg. */
|
||
case 0x71: case 0x75:
|
||
/* pld/pldw reg. */
|
||
return copy_preload_reg (gdbarch, insn, regs, dsc);
|
||
case 0x63: case 0x67: case 0x73: case 0x77:
|
||
return copy_unpred (gdbarch, insn, dsc);
|
||
default:
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
}
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc); /* Probably unreachable. */
|
||
}
|
||
|
||
static int
|
||
decode_unconditional (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
if (bit (insn, 27) == 0)
|
||
return decode_misc_memhint_neon (gdbarch, insn, regs, dsc);
|
||
/* Switch on bits: 0bxxxxx321xxx0xxxxxxxxxxxxxxxxxxxx. */
|
||
else switch (((insn & 0x7000000) >> 23) | ((insn & 0x100000) >> 20))
|
||
{
|
||
case 0x0: case 0x2:
|
||
return copy_unmodified (gdbarch, insn, "srs", dsc);
|
||
|
||
case 0x1: case 0x3:
|
||
return copy_unmodified (gdbarch, insn, "rfe", dsc);
|
||
|
||
case 0x4: case 0x5: case 0x6: case 0x7:
|
||
return copy_b_bl_blx (gdbarch, insn, regs, dsc);
|
||
|
||
case 0x8:
|
||
switch ((insn & 0xe00000) >> 21)
|
||
{
|
||
case 0x1: case 0x3: case 0x4: case 0x5: case 0x6: case 0x7:
|
||
/* stc/stc2. */
|
||
return copy_copro_load_store (gdbarch, insn, regs, dsc);
|
||
|
||
case 0x2:
|
||
return copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc);
|
||
|
||
default:
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
}
|
||
|
||
case 0x9:
|
||
{
|
||
int rn_f = (bits (insn, 16, 19) == 0xf);
|
||
switch ((insn & 0xe00000) >> 21)
|
||
{
|
||
case 0x1: case 0x3:
|
||
/* ldc/ldc2 imm (undefined for rn == pc). */
|
||
return rn_f ? copy_undef (gdbarch, insn, dsc)
|
||
: copy_copro_load_store (gdbarch, insn, regs, dsc);
|
||
|
||
case 0x2:
|
||
return copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc);
|
||
|
||
case 0x4: case 0x5: case 0x6: case 0x7:
|
||
/* ldc/ldc2 lit (undefined for rn != pc). */
|
||
return rn_f ? copy_copro_load_store (gdbarch, insn, regs, dsc)
|
||
: copy_undef (gdbarch, insn, dsc);
|
||
|
||
default:
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
}
|
||
}
|
||
|
||
case 0xa:
|
||
return copy_unmodified (gdbarch, insn, "stc/stc2", dsc);
|
||
|
||
case 0xb:
|
||
if (bits (insn, 16, 19) == 0xf)
|
||
/* ldc/ldc2 lit. */
|
||
return copy_copro_load_store (gdbarch, insn, regs, dsc);
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
|
||
case 0xc:
|
||
if (bit (insn, 4))
|
||
return copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc);
|
||
else
|
||
return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
|
||
|
||
case 0xd:
|
||
if (bit (insn, 4))
|
||
return copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc);
|
||
else
|
||
return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
|
||
|
||
default:
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
}
|
||
}
|
||
|
||
/* Decode miscellaneous instructions in dp/misc encoding space. */
|
||
|
||
static int
|
||
decode_miscellaneous (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int op2 = bits (insn, 4, 6);
|
||
unsigned int op = bits (insn, 21, 22);
|
||
unsigned int op1 = bits (insn, 16, 19);
|
||
|
||
switch (op2)
|
||
{
|
||
case 0x0:
|
||
return copy_unmodified (gdbarch, insn, "mrs/msr", dsc);
|
||
|
||
case 0x1:
|
||
if (op == 0x1) /* bx. */
|
||
return copy_bx_blx_reg (gdbarch, insn, regs, dsc);
|
||
else if (op == 0x3)
|
||
return copy_unmodified (gdbarch, insn, "clz", dsc);
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
|
||
case 0x2:
|
||
if (op == 0x1)
|
||
/* Not really supported. */
|
||
return copy_unmodified (gdbarch, insn, "bxj", dsc);
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
|
||
case 0x3:
|
||
if (op == 0x1)
|
||
return copy_bx_blx_reg (gdbarch, insn, regs, dsc); /* blx register. */
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
|
||
case 0x5:
|
||
return copy_unmodified (gdbarch, insn, "saturating add/sub", dsc);
|
||
|
||
case 0x7:
|
||
if (op == 0x1)
|
||
return copy_unmodified (gdbarch, insn, "bkpt", dsc);
|
||
else if (op == 0x3)
|
||
/* Not really supported. */
|
||
return copy_unmodified (gdbarch, insn, "smc", dsc);
|
||
|
||
default:
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
}
|
||
}
|
||
|
||
static int
|
||
decode_dp_misc (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
if (bit (insn, 25))
|
||
switch (bits (insn, 20, 24))
|
||
{
|
||
case 0x10:
|
||
return copy_unmodified (gdbarch, insn, "movw", dsc);
|
||
|
||
case 0x14:
|
||
return copy_unmodified (gdbarch, insn, "movt", dsc);
|
||
|
||
case 0x12: case 0x16:
|
||
return copy_unmodified (gdbarch, insn, "msr imm", dsc);
|
||
|
||
default:
|
||
return copy_alu_imm (gdbarch, insn, regs, dsc);
|
||
}
|
||
else
|
||
{
|
||
uint32_t op1 = bits (insn, 20, 24), op2 = bits (insn, 4, 7);
|
||
|
||
if ((op1 & 0x19) != 0x10 && (op2 & 0x1) == 0x0)
|
||
return copy_alu_reg (gdbarch, insn, regs, dsc);
|
||
else if ((op1 & 0x19) != 0x10 && (op2 & 0x9) == 0x1)
|
||
return copy_alu_shifted_reg (gdbarch, insn, regs, dsc);
|
||
else if ((op1 & 0x19) == 0x10 && (op2 & 0x8) == 0x0)
|
||
return decode_miscellaneous (gdbarch, insn, regs, dsc);
|
||
else if ((op1 & 0x19) == 0x10 && (op2 & 0x9) == 0x8)
|
||
return copy_unmodified (gdbarch, insn, "halfword mul/mla", dsc);
|
||
else if ((op1 & 0x10) == 0x00 && op2 == 0x9)
|
||
return copy_unmodified (gdbarch, insn, "mul/mla", dsc);
|
||
else if ((op1 & 0x10) == 0x10 && op2 == 0x9)
|
||
return copy_unmodified (gdbarch, insn, "synch", dsc);
|
||
else if (op2 == 0xb || (op2 & 0xd) == 0xd)
|
||
/* 2nd arg means "unpriveleged". */
|
||
return copy_extra_ld_st (gdbarch, insn, (op1 & 0x12) == 0x02, regs,
|
||
dsc);
|
||
}
|
||
|
||
/* Should be unreachable. */
|
||
return 1;
|
||
}
|
||
|
||
static int
|
||
decode_ld_st_word_ubyte (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
int a = bit (insn, 25), b = bit (insn, 4);
|
||
uint32_t op1 = bits (insn, 20, 24);
|
||
int rn_f = bits (insn, 16, 19) == 0xf;
|
||
|
||
if ((!a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02)
|
||
|| (a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02 && !b))
|
||
return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 0, 0);
|
||
else if ((!a && (op1 & 0x17) == 0x02)
|
||
|| (a && (op1 & 0x17) == 0x02 && !b))
|
||
return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 0, 1);
|
||
else if ((!a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03)
|
||
|| (a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03 && !b))
|
||
return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 0, 0);
|
||
else if ((!a && (op1 & 0x17) == 0x03)
|
||
|| (a && (op1 & 0x17) == 0x03 && !b))
|
||
return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 0, 1);
|
||
else if ((!a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06)
|
||
|| (a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06 && !b))
|
||
return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 0);
|
||
else if ((!a && (op1 & 0x17) == 0x06)
|
||
|| (a && (op1 & 0x17) == 0x06 && !b))
|
||
return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 1);
|
||
else if ((!a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07)
|
||
|| (a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07 && !b))
|
||
return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 0);
|
||
else if ((!a && (op1 & 0x17) == 0x07)
|
||
|| (a && (op1 & 0x17) == 0x07 && !b))
|
||
return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 1);
|
||
|
||
/* Should be unreachable. */
|
||
return 1;
|
||
}
|
||
|
||
static int
|
||
decode_media (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
switch (bits (insn, 20, 24))
|
||
{
|
||
case 0x00: case 0x01: case 0x02: case 0x03:
|
||
return copy_unmodified (gdbarch, insn, "parallel add/sub signed", dsc);
|
||
|
||
case 0x04: case 0x05: case 0x06: case 0x07:
|
||
return copy_unmodified (gdbarch, insn, "parallel add/sub unsigned", dsc);
|
||
|
||
case 0x08: case 0x09: case 0x0a: case 0x0b:
|
||
case 0x0c: case 0x0d: case 0x0e: case 0x0f:
|
||
return copy_unmodified (gdbarch, insn,
|
||
"decode/pack/unpack/saturate/reverse", dsc);
|
||
|
||
case 0x18:
|
||
if (bits (insn, 5, 7) == 0) /* op2. */
|
||
{
|
||
if (bits (insn, 12, 15) == 0xf)
|
||
return copy_unmodified (gdbarch, insn, "usad8", dsc);
|
||
else
|
||
return copy_unmodified (gdbarch, insn, "usada8", dsc);
|
||
}
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
|
||
case 0x1a: case 0x1b:
|
||
if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */
|
||
return copy_unmodified (gdbarch, insn, "sbfx", dsc);
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
|
||
case 0x1c: case 0x1d:
|
||
if (bits (insn, 5, 6) == 0x0) /* op2[1:0]. */
|
||
{
|
||
if (bits (insn, 0, 3) == 0xf)
|
||
return copy_unmodified (gdbarch, insn, "bfc", dsc);
|
||
else
|
||
return copy_unmodified (gdbarch, insn, "bfi", dsc);
|
||
}
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
|
||
case 0x1e: case 0x1f:
|
||
if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */
|
||
return copy_unmodified (gdbarch, insn, "ubfx", dsc);
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
}
|
||
|
||
/* Should be unreachable. */
|
||
return 1;
|
||
}
|
||
|
||
static int
|
||
decode_b_bl_ldmstm (struct gdbarch *gdbarch, int32_t insn,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
if (bit (insn, 25))
|
||
return copy_b_bl_blx (gdbarch, insn, regs, dsc);
|
||
else
|
||
return copy_block_xfer (gdbarch, insn, regs, dsc);
|
||
}
|
||
|
||
static int
|
||
decode_ext_reg_ld_st (struct gdbarch *gdbarch, uint32_t insn,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int opcode = bits (insn, 20, 24);
|
||
|
||
switch (opcode)
|
||
{
|
||
case 0x04: case 0x05: /* VFP/Neon mrrc/mcrr. */
|
||
return copy_unmodified (gdbarch, insn, "vfp/neon mrrc/mcrr", dsc);
|
||
|
||
case 0x08: case 0x0a: case 0x0c: case 0x0e:
|
||
case 0x12: case 0x16:
|
||
return copy_unmodified (gdbarch, insn, "vfp/neon vstm/vpush", dsc);
|
||
|
||
case 0x09: case 0x0b: case 0x0d: case 0x0f:
|
||
case 0x13: case 0x17:
|
||
return copy_unmodified (gdbarch, insn, "vfp/neon vldm/vpop", dsc);
|
||
|
||
case 0x10: case 0x14: case 0x18: case 0x1c: /* vstr. */
|
||
case 0x11: case 0x15: case 0x19: case 0x1d: /* vldr. */
|
||
/* Note: no writeback for these instructions. Bit 25 will always be
|
||
zero though (via caller), so the following works OK. */
|
||
return copy_copro_load_store (gdbarch, insn, regs, dsc);
|
||
}
|
||
|
||
/* Should be unreachable. */
|
||
return 1;
|
||
}
|
||
|
||
static int
|
||
decode_svc_copro (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
|
||
struct regcache *regs, struct displaced_step_closure *dsc)
|
||
{
|
||
unsigned int op1 = bits (insn, 20, 25);
|
||
int op = bit (insn, 4);
|
||
unsigned int coproc = bits (insn, 8, 11);
|
||
unsigned int rn = bits (insn, 16, 19);
|
||
|
||
if ((op1 & 0x20) == 0x00 && (op1 & 0x3a) != 0x00 && (coproc & 0xe) == 0xa)
|
||
return decode_ext_reg_ld_st (gdbarch, insn, regs, dsc);
|
||
else if ((op1 & 0x21) == 0x00 && (op1 & 0x3a) != 0x00
|
||
&& (coproc & 0xe) != 0xa)
|
||
/* stc/stc2. */
|
||
return copy_copro_load_store (gdbarch, insn, regs, dsc);
|
||
else if ((op1 & 0x21) == 0x01 && (op1 & 0x3a) != 0x00
|
||
&& (coproc & 0xe) != 0xa)
|
||
/* ldc/ldc2 imm/lit. */
|
||
return copy_copro_load_store (gdbarch, insn, regs, dsc);
|
||
else if ((op1 & 0x3e) == 0x00)
|
||
return copy_undef (gdbarch, insn, dsc);
|
||
else if ((op1 & 0x3e) == 0x04 && (coproc & 0xe) == 0xa)
|
||
return copy_unmodified (gdbarch, insn, "neon 64bit xfer", dsc);
|
||
else if (op1 == 0x04 && (coproc & 0xe) != 0xa)
|
||
return copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc);
|
||
else if (op1 == 0x05 && (coproc & 0xe) != 0xa)
|
||
return copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc);
|
||
else if ((op1 & 0x30) == 0x20 && !op)
|
||
{
|
||
if ((coproc & 0xe) == 0xa)
|
||
return copy_unmodified (gdbarch, insn, "vfp dataproc", dsc);
|
||
else
|
||
return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
|
||
}
|
||
else if ((op1 & 0x30) == 0x20 && op)
|
||
return copy_unmodified (gdbarch, insn, "neon 8/16/32 bit xfer", dsc);
|
||
else if ((op1 & 0x31) == 0x20 && op && (coproc & 0xe) != 0xa)
|
||
return copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc);
|
||
else if ((op1 & 0x31) == 0x21 && op && (coproc & 0xe) != 0xa)
|
||
return copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc);
|
||
else if ((op1 & 0x30) == 0x30)
|
||
return copy_svc (gdbarch, insn, to, regs, dsc);
|
||
else
|
||
return copy_undef (gdbarch, insn, dsc); /* Possibly unreachable. */
|
||
}
|
||
|
||
void
|
||
arm_process_displaced_insn (struct gdbarch *gdbarch, uint32_t insn,
|
||
CORE_ADDR from, CORE_ADDR to, struct regcache *regs,
|
||
struct displaced_step_closure *dsc)
|
||
{
|
||
int err = 0;
|
||
|
||
if (!displaced_in_arm_mode (regs))
|
||
error (_("Displaced stepping is only supported in ARM mode"));
|
||
|
||
/* Most displaced instructions use a 1-instruction scratch space, so set this
|
||
here and override below if/when necessary. */
|
||
dsc->numinsns = 1;
|
||
dsc->insn_addr = from;
|
||
dsc->scratch_base = to;
|
||
dsc->cleanup = NULL;
|
||
dsc->wrote_to_pc = 0;
|
||
|
||
if ((insn & 0xf0000000) == 0xf0000000)
|
||
err = decode_unconditional (gdbarch, insn, regs, dsc);
|
||
else switch (((insn & 0x10) >> 4) | ((insn & 0xe000000) >> 24))
|
||
{
|
||
case 0x0: case 0x1: case 0x2: case 0x3:
|
||
err = decode_dp_misc (gdbarch, insn, regs, dsc);
|
||
break;
|
||
|
||
case 0x4: case 0x5: case 0x6:
|
||
err = decode_ld_st_word_ubyte (gdbarch, insn, regs, dsc);
|
||
break;
|
||
|
||
case 0x7:
|
||
err = decode_media (gdbarch, insn, dsc);
|
||
break;
|
||
|
||
case 0x8: case 0x9: case 0xa: case 0xb:
|
||
err = decode_b_bl_ldmstm (gdbarch, insn, regs, dsc);
|
||
break;
|
||
|
||
case 0xc: case 0xd: case 0xe: case 0xf:
|
||
err = decode_svc_copro (gdbarch, insn, to, regs, dsc);
|
||
break;
|
||
}
|
||
|
||
if (err)
|
||
internal_error (__FILE__, __LINE__,
|
||
_("arm_process_displaced_insn: Instruction decode error"));
|
||
}
|
||
|
||
/* Actually set up the scratch space for a displaced instruction. */
|
||
|
||
void
|
||
arm_displaced_init_closure (struct gdbarch *gdbarch, CORE_ADDR from,
|
||
CORE_ADDR to, struct displaced_step_closure *dsc)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
unsigned int i;
|
||
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
|
||
|
||
/* Poke modified instruction(s). */
|
||
for (i = 0; i < dsc->numinsns; i++)
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: writing insn %.8lx at "
|
||
"%.8lx\n", (unsigned long) dsc->modinsn[i],
|
||
(unsigned long) to + i * 4);
|
||
write_memory_unsigned_integer (to + i * 4, 4, byte_order_for_code,
|
||
dsc->modinsn[i]);
|
||
}
|
||
|
||
/* Put breakpoint afterwards. */
|
||
write_memory (to + dsc->numinsns * 4, tdep->arm_breakpoint,
|
||
tdep->arm_breakpoint_size);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ",
|
||
paddress (gdbarch, from), paddress (gdbarch, to));
|
||
}
|
||
|
||
/* Entry point for copying an instruction into scratch space for displaced
|
||
stepping. */
|
||
|
||
struct displaced_step_closure *
|
||
arm_displaced_step_copy_insn (struct gdbarch *gdbarch,
|
||
CORE_ADDR from, CORE_ADDR to,
|
||
struct regcache *regs)
|
||
{
|
||
struct displaced_step_closure *dsc
|
||
= xmalloc (sizeof (struct displaced_step_closure));
|
||
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
|
||
uint32_t insn = read_memory_unsigned_integer (from, 4, byte_order_for_code);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
|
||
"at %.8lx\n", (unsigned long) insn,
|
||
(unsigned long) from);
|
||
|
||
arm_process_displaced_insn (gdbarch, insn, from, to, regs, dsc);
|
||
arm_displaced_init_closure (gdbarch, from, to, dsc);
|
||
|
||
return dsc;
|
||
}
|
||
|
||
/* Entry point for cleaning things up after a displaced instruction has been
|
||
single-stepped. */
|
||
|
||
void
|
||
arm_displaced_step_fixup (struct gdbarch *gdbarch,
|
||
struct displaced_step_closure *dsc,
|
||
CORE_ADDR from, CORE_ADDR to,
|
||
struct regcache *regs)
|
||
{
|
||
if (dsc->cleanup)
|
||
dsc->cleanup (gdbarch, regs, dsc);
|
||
|
||
if (!dsc->wrote_to_pc)
|
||
regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, dsc->insn_addr + 4);
|
||
}
|
||
|
||
#include "bfd-in2.h"
|
||
#include "libcoff.h"
|
||
|
||
static int
|
||
gdb_print_insn_arm (bfd_vma memaddr, disassemble_info *info)
|
||
{
|
||
if (arm_pc_is_thumb (memaddr))
|
||
{
|
||
static asymbol *asym;
|
||
static combined_entry_type ce;
|
||
static struct coff_symbol_struct csym;
|
||
static struct bfd fake_bfd;
|
||
static bfd_target fake_target;
|
||
|
||
if (csym.native == NULL)
|
||
{
|
||
/* Create a fake symbol vector containing a Thumb symbol.
|
||
This is solely so that the code in print_insn_little_arm()
|
||
and print_insn_big_arm() in opcodes/arm-dis.c will detect
|
||
the presence of a Thumb symbol and switch to decoding
|
||
Thumb instructions. */
|
||
|
||
fake_target.flavour = bfd_target_coff_flavour;
|
||
fake_bfd.xvec = &fake_target;
|
||
ce.u.syment.n_sclass = C_THUMBEXTFUNC;
|
||
csym.native = &ce;
|
||
csym.symbol.the_bfd = &fake_bfd;
|
||
csym.symbol.name = "fake";
|
||
asym = (asymbol *) & csym;
|
||
}
|
||
|
||
memaddr = UNMAKE_THUMB_ADDR (memaddr);
|
||
info->symbols = &asym;
|
||
}
|
||
else
|
||
info->symbols = NULL;
|
||
|
||
if (info->endian == BFD_ENDIAN_BIG)
|
||
return print_insn_big_arm (memaddr, info);
|
||
else
|
||
return print_insn_little_arm (memaddr, info);
|
||
}
|
||
|
||
/* The following define instruction sequences that will cause ARM
|
||
cpu's to take an undefined instruction trap. These are used to
|
||
signal a breakpoint to GDB.
|
||
|
||
The newer ARMv4T cpu's are capable of operating in ARM or Thumb
|
||
modes. A different instruction is required for each mode. The ARM
|
||
cpu's can also be big or little endian. Thus four different
|
||
instructions are needed to support all cases.
|
||
|
||
Note: ARMv4 defines several new instructions that will take the
|
||
undefined instruction trap. ARM7TDMI is nominally ARMv4T, but does
|
||
not in fact add the new instructions. The new undefined
|
||
instructions in ARMv4 are all instructions that had no defined
|
||
behaviour in earlier chips. There is no guarantee that they will
|
||
raise an exception, but may be treated as NOP's. In practice, it
|
||
may only safe to rely on instructions matching:
|
||
|
||
3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
|
||
1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
|
||
C C C C 0 1 1 x x x x x x x x x x x x x x x x x x x x 1 x x x x
|
||
|
||
Even this may only true if the condition predicate is true. The
|
||
following use a condition predicate of ALWAYS so it is always TRUE.
|
||
|
||
There are other ways of forcing a breakpoint. GNU/Linux, RISC iX,
|
||
and NetBSD all use a software interrupt rather than an undefined
|
||
instruction to force a trap. This can be handled by by the
|
||
abi-specific code during establishment of the gdbarch vector. */
|
||
|
||
#define ARM_LE_BREAKPOINT {0xFE,0xDE,0xFF,0xE7}
|
||
#define ARM_BE_BREAKPOINT {0xE7,0xFF,0xDE,0xFE}
|
||
#define THUMB_LE_BREAKPOINT {0xbe,0xbe}
|
||
#define THUMB_BE_BREAKPOINT {0xbe,0xbe}
|
||
|
||
static const char arm_default_arm_le_breakpoint[] = ARM_LE_BREAKPOINT;
|
||
static const char arm_default_arm_be_breakpoint[] = ARM_BE_BREAKPOINT;
|
||
static const char arm_default_thumb_le_breakpoint[] = THUMB_LE_BREAKPOINT;
|
||
static const char arm_default_thumb_be_breakpoint[] = THUMB_BE_BREAKPOINT;
|
||
|
||
/* Determine the type and size of breakpoint to insert at PCPTR. Uses
|
||
the program counter value to determine whether a 16-bit or 32-bit
|
||
breakpoint should be used. It returns a pointer to a string of
|
||
bytes that encode a breakpoint instruction, stores the length of
|
||
the string to *lenptr, and adjusts the program counter (if
|
||
necessary) to point to the actual memory location where the
|
||
breakpoint should be inserted. */
|
||
|
||
static const unsigned char *
|
||
arm_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr, int *lenptr)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
|
||
|
||
if (arm_pc_is_thumb (*pcptr))
|
||
{
|
||
*pcptr = UNMAKE_THUMB_ADDR (*pcptr);
|
||
|
||
/* If we have a separate 32-bit breakpoint instruction for Thumb-2,
|
||
check whether we are replacing a 32-bit instruction. */
|
||
if (tdep->thumb2_breakpoint != NULL)
|
||
{
|
||
gdb_byte buf[2];
|
||
if (target_read_memory (*pcptr, buf, 2) == 0)
|
||
{
|
||
unsigned short inst1;
|
||
inst1 = extract_unsigned_integer (buf, 2, byte_order_for_code);
|
||
if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
|
||
{
|
||
*lenptr = tdep->thumb2_breakpoint_size;
|
||
return tdep->thumb2_breakpoint;
|
||
}
|
||
}
|
||
}
|
||
|
||
*lenptr = tdep->thumb_breakpoint_size;
|
||
return tdep->thumb_breakpoint;
|
||
}
|
||
else
|
||
{
|
||
*lenptr = tdep->arm_breakpoint_size;
|
||
return tdep->arm_breakpoint;
|
||
}
|
||
}
|
||
|
||
static void
|
||
arm_remote_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr,
|
||
int *kindptr)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
arm_breakpoint_from_pc (gdbarch, pcptr, kindptr);
|
||
|
||
if (arm_pc_is_thumb (*pcptr) && *kindptr == 4)
|
||
/* The documented magic value for a 32-bit Thumb-2 breakpoint, so
|
||
that this is not confused with a 32-bit ARM breakpoint. */
|
||
*kindptr = 3;
|
||
}
|
||
|
||
/* Extract from an array REGBUF containing the (raw) register state a
|
||
function return value of type TYPE, and copy that, in virtual
|
||
format, into VALBUF. */
|
||
|
||
static void
|
||
arm_extract_return_value (struct type *type, struct regcache *regs,
|
||
gdb_byte *valbuf)
|
||
{
|
||
struct gdbarch *gdbarch = get_regcache_arch (regs);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
|
||
if (TYPE_CODE_FLT == TYPE_CODE (type))
|
||
{
|
||
switch (gdbarch_tdep (gdbarch)->fp_model)
|
||
{
|
||
case ARM_FLOAT_FPA:
|
||
{
|
||
/* The value is in register F0 in internal format. We need to
|
||
extract the raw value and then convert it to the desired
|
||
internal type. */
|
||
bfd_byte tmpbuf[FP_REGISTER_SIZE];
|
||
|
||
regcache_cooked_read (regs, ARM_F0_REGNUM, tmpbuf);
|
||
convert_from_extended (floatformat_from_type (type), tmpbuf,
|
||
valbuf, gdbarch_byte_order (gdbarch));
|
||
}
|
||
break;
|
||
|
||
case ARM_FLOAT_SOFT_FPA:
|
||
case ARM_FLOAT_SOFT_VFP:
|
||
/* ARM_FLOAT_VFP can arise if this is a variadic function so
|
||
not using the VFP ABI code. */
|
||
case ARM_FLOAT_VFP:
|
||
regcache_cooked_read (regs, ARM_A1_REGNUM, valbuf);
|
||
if (TYPE_LENGTH (type) > 4)
|
||
regcache_cooked_read (regs, ARM_A1_REGNUM + 1,
|
||
valbuf + INT_REGISTER_SIZE);
|
||
break;
|
||
|
||
default:
|
||
internal_error
|
||
(__FILE__, __LINE__,
|
||
_("arm_extract_return_value: Floating point model not supported"));
|
||
break;
|
||
}
|
||
}
|
||
else if (TYPE_CODE (type) == TYPE_CODE_INT
|
||
|| TYPE_CODE (type) == TYPE_CODE_CHAR
|
||
|| TYPE_CODE (type) == TYPE_CODE_BOOL
|
||
|| TYPE_CODE (type) == TYPE_CODE_PTR
|
||
|| TYPE_CODE (type) == TYPE_CODE_REF
|
||
|| TYPE_CODE (type) == TYPE_CODE_ENUM)
|
||
{
|
||
/* If the the type is a plain integer, then the access is
|
||
straight-forward. Otherwise we have to play around a bit more. */
|
||
int len = TYPE_LENGTH (type);
|
||
int regno = ARM_A1_REGNUM;
|
||
ULONGEST tmp;
|
||
|
||
while (len > 0)
|
||
{
|
||
/* By using store_unsigned_integer we avoid having to do
|
||
anything special for small big-endian values. */
|
||
regcache_cooked_read_unsigned (regs, regno++, &tmp);
|
||
store_unsigned_integer (valbuf,
|
||
(len > INT_REGISTER_SIZE
|
||
? INT_REGISTER_SIZE : len),
|
||
byte_order, tmp);
|
||
len -= INT_REGISTER_SIZE;
|
||
valbuf += INT_REGISTER_SIZE;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* For a structure or union the behaviour is as if the value had
|
||
been stored to word-aligned memory and then loaded into
|
||
registers with 32-bit load instruction(s). */
|
||
int len = TYPE_LENGTH (type);
|
||
int regno = ARM_A1_REGNUM;
|
||
bfd_byte tmpbuf[INT_REGISTER_SIZE];
|
||
|
||
while (len > 0)
|
||
{
|
||
regcache_cooked_read (regs, regno++, tmpbuf);
|
||
memcpy (valbuf, tmpbuf,
|
||
len > INT_REGISTER_SIZE ? INT_REGISTER_SIZE : len);
|
||
len -= INT_REGISTER_SIZE;
|
||
valbuf += INT_REGISTER_SIZE;
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
/* Will a function return an aggregate type in memory or in a
|
||
register? Return 0 if an aggregate type can be returned in a
|
||
register, 1 if it must be returned in memory. */
|
||
|
||
static int
|
||
arm_return_in_memory (struct gdbarch *gdbarch, struct type *type)
|
||
{
|
||
int nRc;
|
||
enum type_code code;
|
||
|
||
CHECK_TYPEDEF (type);
|
||
|
||
/* In the ARM ABI, "integer" like aggregate types are returned in
|
||
registers. For an aggregate type to be integer like, its size
|
||
must be less than or equal to INT_REGISTER_SIZE and the
|
||
offset of each addressable subfield must be zero. Note that bit
|
||
fields are not addressable, and all addressable subfields of
|
||
unions always start at offset zero.
|
||
|
||
This function is based on the behaviour of GCC 2.95.1.
|
||
See: gcc/arm.c: arm_return_in_memory() for details.
|
||
|
||
Note: All versions of GCC before GCC 2.95.2 do not set up the
|
||
parameters correctly for a function returning the following
|
||
structure: struct { float f;}; This should be returned in memory,
|
||
not a register. Richard Earnshaw sent me a patch, but I do not
|
||
know of any way to detect if a function like the above has been
|
||
compiled with the correct calling convention. */
|
||
|
||
/* All aggregate types that won't fit in a register must be returned
|
||
in memory. */
|
||
if (TYPE_LENGTH (type) > INT_REGISTER_SIZE)
|
||
{
|
||
return 1;
|
||
}
|
||
|
||
/* The AAPCS says all aggregates not larger than a word are returned
|
||
in a register. */
|
||
if (gdbarch_tdep (gdbarch)->arm_abi != ARM_ABI_APCS)
|
||
return 0;
|
||
|
||
/* The only aggregate types that can be returned in a register are
|
||
structs and unions. Arrays must be returned in memory. */
|
||
code = TYPE_CODE (type);
|
||
if ((TYPE_CODE_STRUCT != code) && (TYPE_CODE_UNION != code))
|
||
{
|
||
return 1;
|
||
}
|
||
|
||
/* Assume all other aggregate types can be returned in a register.
|
||
Run a check for structures, unions and arrays. */
|
||
nRc = 0;
|
||
|
||
if ((TYPE_CODE_STRUCT == code) || (TYPE_CODE_UNION == code))
|
||
{
|
||
int i;
|
||
/* Need to check if this struct/union is "integer" like. For
|
||
this to be true, its size must be less than or equal to
|
||
INT_REGISTER_SIZE and the offset of each addressable
|
||
subfield must be zero. Note that bit fields are not
|
||
addressable, and unions always start at offset zero. If any
|
||
of the subfields is a floating point type, the struct/union
|
||
cannot be an integer type. */
|
||
|
||
/* For each field in the object, check:
|
||
1) Is it FP? --> yes, nRc = 1;
|
||
2) Is it addressable (bitpos != 0) and
|
||
not packed (bitsize == 0)?
|
||
--> yes, nRc = 1
|
||
*/
|
||
|
||
for (i = 0; i < TYPE_NFIELDS (type); i++)
|
||
{
|
||
enum type_code field_type_code;
|
||
field_type_code = TYPE_CODE (check_typedef (TYPE_FIELD_TYPE (type, i)));
|
||
|
||
/* Is it a floating point type field? */
|
||
if (field_type_code == TYPE_CODE_FLT)
|
||
{
|
||
nRc = 1;
|
||
break;
|
||
}
|
||
|
||
/* If bitpos != 0, then we have to care about it. */
|
||
if (TYPE_FIELD_BITPOS (type, i) != 0)
|
||
{
|
||
/* Bitfields are not addressable. If the field bitsize is
|
||
zero, then the field is not packed. Hence it cannot be
|
||
a bitfield or any other packed type. */
|
||
if (TYPE_FIELD_BITSIZE (type, i) == 0)
|
||
{
|
||
nRc = 1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
return nRc;
|
||
}
|
||
|
||
/* Write into appropriate registers a function return value of type
|
||
TYPE, given in virtual format. */
|
||
|
||
static void
|
||
arm_store_return_value (struct type *type, struct regcache *regs,
|
||
const gdb_byte *valbuf)
|
||
{
|
||
struct gdbarch *gdbarch = get_regcache_arch (regs);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
|
||
if (TYPE_CODE (type) == TYPE_CODE_FLT)
|
||
{
|
||
char buf[MAX_REGISTER_SIZE];
|
||
|
||
switch (gdbarch_tdep (gdbarch)->fp_model)
|
||
{
|
||
case ARM_FLOAT_FPA:
|
||
|
||
convert_to_extended (floatformat_from_type (type), buf, valbuf,
|
||
gdbarch_byte_order (gdbarch));
|
||
regcache_cooked_write (regs, ARM_F0_REGNUM, buf);
|
||
break;
|
||
|
||
case ARM_FLOAT_SOFT_FPA:
|
||
case ARM_FLOAT_SOFT_VFP:
|
||
/* ARM_FLOAT_VFP can arise if this is a variadic function so
|
||
not using the VFP ABI code. */
|
||
case ARM_FLOAT_VFP:
|
||
regcache_cooked_write (regs, ARM_A1_REGNUM, valbuf);
|
||
if (TYPE_LENGTH (type) > 4)
|
||
regcache_cooked_write (regs, ARM_A1_REGNUM + 1,
|
||
valbuf + INT_REGISTER_SIZE);
|
||
break;
|
||
|
||
default:
|
||
internal_error
|
||
(__FILE__, __LINE__,
|
||
_("arm_store_return_value: Floating point model not supported"));
|
||
break;
|
||
}
|
||
}
|
||
else if (TYPE_CODE (type) == TYPE_CODE_INT
|
||
|| TYPE_CODE (type) == TYPE_CODE_CHAR
|
||
|| TYPE_CODE (type) == TYPE_CODE_BOOL
|
||
|| TYPE_CODE (type) == TYPE_CODE_PTR
|
||
|| TYPE_CODE (type) == TYPE_CODE_REF
|
||
|| TYPE_CODE (type) == TYPE_CODE_ENUM)
|
||
{
|
||
if (TYPE_LENGTH (type) <= 4)
|
||
{
|
||
/* Values of one word or less are zero/sign-extended and
|
||
returned in r0. */
|
||
bfd_byte tmpbuf[INT_REGISTER_SIZE];
|
||
LONGEST val = unpack_long (type, valbuf);
|
||
|
||
store_signed_integer (tmpbuf, INT_REGISTER_SIZE, byte_order, val);
|
||
regcache_cooked_write (regs, ARM_A1_REGNUM, tmpbuf);
|
||
}
|
||
else
|
||
{
|
||
/* Integral values greater than one word are stored in consecutive
|
||
registers starting with r0. This will always be a multiple of
|
||
the regiser size. */
|
||
int len = TYPE_LENGTH (type);
|
||
int regno = ARM_A1_REGNUM;
|
||
|
||
while (len > 0)
|
||
{
|
||
regcache_cooked_write (regs, regno++, valbuf);
|
||
len -= INT_REGISTER_SIZE;
|
||
valbuf += INT_REGISTER_SIZE;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* For a structure or union the behaviour is as if the value had
|
||
been stored to word-aligned memory and then loaded into
|
||
registers with 32-bit load instruction(s). */
|
||
int len = TYPE_LENGTH (type);
|
||
int regno = ARM_A1_REGNUM;
|
||
bfd_byte tmpbuf[INT_REGISTER_SIZE];
|
||
|
||
while (len > 0)
|
||
{
|
||
memcpy (tmpbuf, valbuf,
|
||
len > INT_REGISTER_SIZE ? INT_REGISTER_SIZE : len);
|
||
regcache_cooked_write (regs, regno++, tmpbuf);
|
||
len -= INT_REGISTER_SIZE;
|
||
valbuf += INT_REGISTER_SIZE;
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
/* Handle function return values. */
|
||
|
||
static enum return_value_convention
|
||
arm_return_value (struct gdbarch *gdbarch, struct type *func_type,
|
||
struct type *valtype, struct regcache *regcache,
|
||
gdb_byte *readbuf, const gdb_byte *writebuf)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
enum arm_vfp_cprc_base_type vfp_base_type;
|
||
int vfp_base_count;
|
||
|
||
if (arm_vfp_abi_for_function (gdbarch, func_type)
|
||
&& arm_vfp_call_candidate (valtype, &vfp_base_type, &vfp_base_count))
|
||
{
|
||
int reg_char = arm_vfp_cprc_reg_char (vfp_base_type);
|
||
int unit_length = arm_vfp_cprc_unit_length (vfp_base_type);
|
||
int i;
|
||
for (i = 0; i < vfp_base_count; i++)
|
||
{
|
||
if (reg_char == 'q')
|
||
{
|
||
if (writebuf)
|
||
arm_neon_quad_write (gdbarch, regcache, i,
|
||
writebuf + i * unit_length);
|
||
|
||
if (readbuf)
|
||
arm_neon_quad_read (gdbarch, regcache, i,
|
||
readbuf + i * unit_length);
|
||
}
|
||
else
|
||
{
|
||
char name_buf[4];
|
||
int regnum;
|
||
|
||
sprintf (name_buf, "%c%d", reg_char, i);
|
||
regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
|
||
strlen (name_buf));
|
||
if (writebuf)
|
||
regcache_cooked_write (regcache, regnum,
|
||
writebuf + i * unit_length);
|
||
if (readbuf)
|
||
regcache_cooked_read (regcache, regnum,
|
||
readbuf + i * unit_length);
|
||
}
|
||
}
|
||
return RETURN_VALUE_REGISTER_CONVENTION;
|
||
}
|
||
|
||
if (TYPE_CODE (valtype) == TYPE_CODE_STRUCT
|
||
|| TYPE_CODE (valtype) == TYPE_CODE_UNION
|
||
|| TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
|
||
{
|
||
if (tdep->struct_return == pcc_struct_return
|
||
|| arm_return_in_memory (gdbarch, valtype))
|
||
return RETURN_VALUE_STRUCT_CONVENTION;
|
||
}
|
||
|
||
if (writebuf)
|
||
arm_store_return_value (valtype, regcache, writebuf);
|
||
|
||
if (readbuf)
|
||
arm_extract_return_value (valtype, regcache, readbuf);
|
||
|
||
return RETURN_VALUE_REGISTER_CONVENTION;
|
||
}
|
||
|
||
|
||
static int
|
||
arm_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
CORE_ADDR jb_addr;
|
||
char buf[INT_REGISTER_SIZE];
|
||
|
||
jb_addr = get_frame_register_unsigned (frame, ARM_A1_REGNUM);
|
||
|
||
if (target_read_memory (jb_addr + tdep->jb_pc * tdep->jb_elt_size, buf,
|
||
INT_REGISTER_SIZE))
|
||
return 0;
|
||
|
||
*pc = extract_unsigned_integer (buf, INT_REGISTER_SIZE, byte_order);
|
||
return 1;
|
||
}
|
||
|
||
/* Recognize GCC and GNU ld's trampolines. If we are in a trampoline,
|
||
return the target PC. Otherwise return 0. */
|
||
|
||
CORE_ADDR
|
||
arm_skip_stub (struct frame_info *frame, CORE_ADDR pc)
|
||
{
|
||
char *name;
|
||
int namelen;
|
||
CORE_ADDR start_addr;
|
||
|
||
/* Find the starting address and name of the function containing the PC. */
|
||
if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0)
|
||
return 0;
|
||
|
||
/* If PC is in a Thumb call or return stub, return the address of the
|
||
target PC, which is in a register. The thunk functions are called
|
||
_call_via_xx, where x is the register name. The possible names
|
||
are r0-r9, sl, fp, ip, sp, and lr. ARM RealView has similar
|
||
functions, named __ARM_call_via_r[0-7]. */
|
||
if (strncmp (name, "_call_via_", 10) == 0
|
||
|| strncmp (name, "__ARM_call_via_", strlen ("__ARM_call_via_")) == 0)
|
||
{
|
||
/* Use the name suffix to determine which register contains the
|
||
target PC. */
|
||
static char *table[15] =
|
||
{"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
|
||
"r8", "r9", "sl", "fp", "ip", "sp", "lr"
|
||
};
|
||
int regno;
|
||
int offset = strlen (name) - 2;
|
||
|
||
for (regno = 0; regno <= 14; regno++)
|
||
if (strcmp (&name[offset], table[regno]) == 0)
|
||
return get_frame_register_unsigned (frame, regno);
|
||
}
|
||
|
||
/* GNU ld generates __foo_from_arm or __foo_from_thumb for
|
||
non-interworking calls to foo. We could decode the stubs
|
||
to find the target but it's easier to use the symbol table. */
|
||
namelen = strlen (name);
|
||
if (name[0] == '_' && name[1] == '_'
|
||
&& ((namelen > 2 + strlen ("_from_thumb")
|
||
&& strncmp (name + namelen - strlen ("_from_thumb"), "_from_thumb",
|
||
strlen ("_from_thumb")) == 0)
|
||
|| (namelen > 2 + strlen ("_from_arm")
|
||
&& strncmp (name + namelen - strlen ("_from_arm"), "_from_arm",
|
||
strlen ("_from_arm")) == 0)))
|
||
{
|
||
char *target_name;
|
||
int target_len = namelen - 2;
|
||
struct minimal_symbol *minsym;
|
||
struct objfile *objfile;
|
||
struct obj_section *sec;
|
||
|
||
if (name[namelen - 1] == 'b')
|
||
target_len -= strlen ("_from_thumb");
|
||
else
|
||
target_len -= strlen ("_from_arm");
|
||
|
||
target_name = alloca (target_len + 1);
|
||
memcpy (target_name, name + 2, target_len);
|
||
target_name[target_len] = '\0';
|
||
|
||
sec = find_pc_section (pc);
|
||
objfile = (sec == NULL) ? NULL : sec->objfile;
|
||
minsym = lookup_minimal_symbol (target_name, NULL, objfile);
|
||
if (minsym != NULL)
|
||
return SYMBOL_VALUE_ADDRESS (minsym);
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
return 0; /* not a stub */
|
||
}
|
||
|
||
static void
|
||
set_arm_command (char *args, int from_tty)
|
||
{
|
||
printf_unfiltered (_("\
|
||
\"set arm\" must be followed by an apporpriate subcommand.\n"));
|
||
help_list (setarmcmdlist, "set arm ", all_commands, gdb_stdout);
|
||
}
|
||
|
||
static void
|
||
show_arm_command (char *args, int from_tty)
|
||
{
|
||
cmd_show_list (showarmcmdlist, from_tty, "");
|
||
}
|
||
|
||
static void
|
||
arm_update_current_architecture (void)
|
||
{
|
||
struct gdbarch_info info;
|
||
|
||
/* If the current architecture is not ARM, we have nothing to do. */
|
||
if (gdbarch_bfd_arch_info (target_gdbarch)->arch != bfd_arch_arm)
|
||
return;
|
||
|
||
/* Update the architecture. */
|
||
gdbarch_info_init (&info);
|
||
|
||
if (!gdbarch_update_p (info))
|
||
internal_error (__FILE__, __LINE__, "could not update architecture");
|
||
}
|
||
|
||
static void
|
||
set_fp_model_sfunc (char *args, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
enum arm_float_model fp_model;
|
||
|
||
for (fp_model = ARM_FLOAT_AUTO; fp_model != ARM_FLOAT_LAST; fp_model++)
|
||
if (strcmp (current_fp_model, fp_model_strings[fp_model]) == 0)
|
||
{
|
||
arm_fp_model = fp_model;
|
||
break;
|
||
}
|
||
|
||
if (fp_model == ARM_FLOAT_LAST)
|
||
internal_error (__FILE__, __LINE__, _("Invalid fp model accepted: %s."),
|
||
current_fp_model);
|
||
|
||
arm_update_current_architecture ();
|
||
}
|
||
|
||
static void
|
||
show_fp_model (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (target_gdbarch);
|
||
|
||
if (arm_fp_model == ARM_FLOAT_AUTO
|
||
&& gdbarch_bfd_arch_info (target_gdbarch)->arch == bfd_arch_arm)
|
||
fprintf_filtered (file, _("\
|
||
The current ARM floating point model is \"auto\" (currently \"%s\").\n"),
|
||
fp_model_strings[tdep->fp_model]);
|
||
else
|
||
fprintf_filtered (file, _("\
|
||
The current ARM floating point model is \"%s\".\n"),
|
||
fp_model_strings[arm_fp_model]);
|
||
}
|
||
|
||
static void
|
||
arm_set_abi (char *args, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
enum arm_abi_kind arm_abi;
|
||
|
||
for (arm_abi = ARM_ABI_AUTO; arm_abi != ARM_ABI_LAST; arm_abi++)
|
||
if (strcmp (arm_abi_string, arm_abi_strings[arm_abi]) == 0)
|
||
{
|
||
arm_abi_global = arm_abi;
|
||
break;
|
||
}
|
||
|
||
if (arm_abi == ARM_ABI_LAST)
|
||
internal_error (__FILE__, __LINE__, _("Invalid ABI accepted: %s."),
|
||
arm_abi_string);
|
||
|
||
arm_update_current_architecture ();
|
||
}
|
||
|
||
static void
|
||
arm_show_abi (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (target_gdbarch);
|
||
|
||
if (arm_abi_global == ARM_ABI_AUTO
|
||
&& gdbarch_bfd_arch_info (target_gdbarch)->arch == bfd_arch_arm)
|
||
fprintf_filtered (file, _("\
|
||
The current ARM ABI is \"auto\" (currently \"%s\").\n"),
|
||
arm_abi_strings[tdep->arm_abi]);
|
||
else
|
||
fprintf_filtered (file, _("The current ARM ABI is \"%s\".\n"),
|
||
arm_abi_string);
|
||
}
|
||
|
||
static void
|
||
arm_show_fallback_mode (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (target_gdbarch);
|
||
|
||
fprintf_filtered (file, _("\
|
||
The current execution mode assumed (when symbols are unavailable) is \"%s\".\n"),
|
||
arm_fallback_mode_string);
|
||
}
|
||
|
||
static void
|
||
arm_show_force_mode (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (target_gdbarch);
|
||
|
||
fprintf_filtered (file, _("\
|
||
The current execution mode assumed (even when symbols are available) is \"%s\".\n"),
|
||
arm_force_mode_string);
|
||
}
|
||
|
||
/* If the user changes the register disassembly style used for info
|
||
register and other commands, we have to also switch the style used
|
||
in opcodes for disassembly output. This function is run in the "set
|
||
arm disassembly" command, and does that. */
|
||
|
||
static void
|
||
set_disassembly_style_sfunc (char *args, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
set_disassembly_style ();
|
||
}
|
||
|
||
/* Return the ARM register name corresponding to register I. */
|
||
static const char *
|
||
arm_register_name (struct gdbarch *gdbarch, int i)
|
||
{
|
||
const int num_regs = gdbarch_num_regs (gdbarch);
|
||
|
||
if (gdbarch_tdep (gdbarch)->have_vfp_pseudos
|
||
&& i >= num_regs && i < num_regs + 32)
|
||
{
|
||
static const char *const vfp_pseudo_names[] = {
|
||
"s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7",
|
||
"s8", "s9", "s10", "s11", "s12", "s13", "s14", "s15",
|
||
"s16", "s17", "s18", "s19", "s20", "s21", "s22", "s23",
|
||
"s24", "s25", "s26", "s27", "s28", "s29", "s30", "s31",
|
||
};
|
||
|
||
return vfp_pseudo_names[i - num_regs];
|
||
}
|
||
|
||
if (gdbarch_tdep (gdbarch)->have_neon_pseudos
|
||
&& i >= num_regs + 32 && i < num_regs + 32 + 16)
|
||
{
|
||
static const char *const neon_pseudo_names[] = {
|
||
"q0", "q1", "q2", "q3", "q4", "q5", "q6", "q7",
|
||
"q8", "q9", "q10", "q11", "q12", "q13", "q14", "q15",
|
||
};
|
||
|
||
return neon_pseudo_names[i - num_regs - 32];
|
||
}
|
||
|
||
if (i >= ARRAY_SIZE (arm_register_names))
|
||
/* These registers are only supported on targets which supply
|
||
an XML description. */
|
||
return "";
|
||
|
||
return arm_register_names[i];
|
||
}
|
||
|
||
static void
|
||
set_disassembly_style (void)
|
||
{
|
||
int current;
|
||
|
||
/* Find the style that the user wants. */
|
||
for (current = 0; current < num_disassembly_options; current++)
|
||
if (disassembly_style == valid_disassembly_styles[current])
|
||
break;
|
||
gdb_assert (current < num_disassembly_options);
|
||
|
||
/* Synchronize the disassembler. */
|
||
set_arm_regname_option (current);
|
||
}
|
||
|
||
/* Test whether the coff symbol specific value corresponds to a Thumb
|
||
function. */
|
||
|
||
static int
|
||
coff_sym_is_thumb (int val)
|
||
{
|
||
return (val == C_THUMBEXT
|
||
|| val == C_THUMBSTAT
|
||
|| val == C_THUMBEXTFUNC
|
||
|| val == C_THUMBSTATFUNC
|
||
|| val == C_THUMBLABEL);
|
||
}
|
||
|
||
/* arm_coff_make_msymbol_special()
|
||
arm_elf_make_msymbol_special()
|
||
|
||
These functions test whether the COFF or ELF symbol corresponds to
|
||
an address in thumb code, and set a "special" bit in a minimal
|
||
symbol to indicate that it does. */
|
||
|
||
static void
|
||
arm_elf_make_msymbol_special(asymbol *sym, struct minimal_symbol *msym)
|
||
{
|
||
/* Thumb symbols are of type STT_LOPROC, (synonymous with
|
||
STT_ARM_TFUNC). */
|
||
if (ELF_ST_TYPE (((elf_symbol_type *)sym)->internal_elf_sym.st_info)
|
||
== STT_LOPROC)
|
||
MSYMBOL_SET_SPECIAL (msym);
|
||
}
|
||
|
||
static void
|
||
arm_coff_make_msymbol_special(int val, struct minimal_symbol *msym)
|
||
{
|
||
if (coff_sym_is_thumb (val))
|
||
MSYMBOL_SET_SPECIAL (msym);
|
||
}
|
||
|
||
static void
|
||
arm_objfile_data_free (struct objfile *objfile, void *arg)
|
||
{
|
||
struct arm_per_objfile *data = arg;
|
||
unsigned int i;
|
||
|
||
for (i = 0; i < objfile->obfd->section_count; i++)
|
||
VEC_free (arm_mapping_symbol_s, data->section_maps[i]);
|
||
}
|
||
|
||
static void
|
||
arm_record_special_symbol (struct gdbarch *gdbarch, struct objfile *objfile,
|
||
asymbol *sym)
|
||
{
|
||
const char *name = bfd_asymbol_name (sym);
|
||
struct arm_per_objfile *data;
|
||
VEC(arm_mapping_symbol_s) **map_p;
|
||
struct arm_mapping_symbol new_map_sym;
|
||
|
||
gdb_assert (name[0] == '$');
|
||
if (name[1] != 'a' && name[1] != 't' && name[1] != 'd')
|
||
return;
|
||
|
||
data = objfile_data (objfile, arm_objfile_data_key);
|
||
if (data == NULL)
|
||
{
|
||
data = OBSTACK_ZALLOC (&objfile->objfile_obstack,
|
||
struct arm_per_objfile);
|
||
set_objfile_data (objfile, arm_objfile_data_key, data);
|
||
data->section_maps = OBSTACK_CALLOC (&objfile->objfile_obstack,
|
||
objfile->obfd->section_count,
|
||
VEC(arm_mapping_symbol_s) *);
|
||
}
|
||
map_p = &data->section_maps[bfd_get_section (sym)->index];
|
||
|
||
new_map_sym.value = sym->value;
|
||
new_map_sym.type = name[1];
|
||
|
||
/* Assume that most mapping symbols appear in order of increasing
|
||
value. If they were randomly distributed, it would be faster to
|
||
always push here and then sort at first use. */
|
||
if (!VEC_empty (arm_mapping_symbol_s, *map_p))
|
||
{
|
||
struct arm_mapping_symbol *prev_map_sym;
|
||
|
||
prev_map_sym = VEC_last (arm_mapping_symbol_s, *map_p);
|
||
if (prev_map_sym->value >= sym->value)
|
||
{
|
||
unsigned int idx;
|
||
idx = VEC_lower_bound (arm_mapping_symbol_s, *map_p, &new_map_sym,
|
||
arm_compare_mapping_symbols);
|
||
VEC_safe_insert (arm_mapping_symbol_s, *map_p, idx, &new_map_sym);
|
||
return;
|
||
}
|
||
}
|
||
|
||
VEC_safe_push (arm_mapping_symbol_s, *map_p, &new_map_sym);
|
||
}
|
||
|
||
static void
|
||
arm_write_pc (struct regcache *regcache, CORE_ADDR pc)
|
||
{
|
||
regcache_cooked_write_unsigned (regcache, ARM_PC_REGNUM, pc);
|
||
|
||
/* If necessary, set the T bit. */
|
||
if (arm_apcs_32)
|
||
{
|
||
ULONGEST val;
|
||
regcache_cooked_read_unsigned (regcache, ARM_PS_REGNUM, &val);
|
||
if (arm_pc_is_thumb (pc))
|
||
regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM, val | CPSR_T);
|
||
else
|
||
regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM,
|
||
val & ~(ULONGEST) CPSR_T);
|
||
}
|
||
}
|
||
|
||
/* Read the contents of a NEON quad register, by reading from two
|
||
double registers. This is used to implement the quad pseudo
|
||
registers, and for argument passing in case the quad registers are
|
||
missing; vectors are passed in quad registers when using the VFP
|
||
ABI, even if a NEON unit is not present. REGNUM is the index of
|
||
the quad register, in [0, 15]. */
|
||
|
||
static void
|
||
arm_neon_quad_read (struct gdbarch *gdbarch, struct regcache *regcache,
|
||
int regnum, gdb_byte *buf)
|
||
{
|
||
char name_buf[4];
|
||
gdb_byte reg_buf[8];
|
||
int offset, double_regnum;
|
||
|
||
sprintf (name_buf, "d%d", regnum << 1);
|
||
double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
|
||
strlen (name_buf));
|
||
|
||
/* d0 is always the least significant half of q0. */
|
||
if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
|
||
offset = 8;
|
||
else
|
||
offset = 0;
|
||
|
||
regcache_raw_read (regcache, double_regnum, reg_buf);
|
||
memcpy (buf + offset, reg_buf, 8);
|
||
|
||
offset = 8 - offset;
|
||
regcache_raw_read (regcache, double_regnum + 1, reg_buf);
|
||
memcpy (buf + offset, reg_buf, 8);
|
||
}
|
||
|
||
static void
|
||
arm_pseudo_read (struct gdbarch *gdbarch, struct regcache *regcache,
|
||
int regnum, gdb_byte *buf)
|
||
{
|
||
const int num_regs = gdbarch_num_regs (gdbarch);
|
||
char name_buf[4];
|
||
gdb_byte reg_buf[8];
|
||
int offset, double_regnum;
|
||
|
||
gdb_assert (regnum >= num_regs);
|
||
regnum -= num_regs;
|
||
|
||
if (gdbarch_tdep (gdbarch)->have_neon_pseudos && regnum >= 32 && regnum < 48)
|
||
/* Quad-precision register. */
|
||
arm_neon_quad_read (gdbarch, regcache, regnum - 32, buf);
|
||
else
|
||
{
|
||
/* Single-precision register. */
|
||
gdb_assert (regnum < 32);
|
||
|
||
/* s0 is always the least significant half of d0. */
|
||
if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
|
||
offset = (regnum & 1) ? 0 : 4;
|
||
else
|
||
offset = (regnum & 1) ? 4 : 0;
|
||
|
||
sprintf (name_buf, "d%d", regnum >> 1);
|
||
double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
|
||
strlen (name_buf));
|
||
|
||
regcache_raw_read (regcache, double_regnum, reg_buf);
|
||
memcpy (buf, reg_buf + offset, 4);
|
||
}
|
||
}
|
||
|
||
/* Store the contents of BUF to a NEON quad register, by writing to
|
||
two double registers. This is used to implement the quad pseudo
|
||
registers, and for argument passing in case the quad registers are
|
||
missing; vectors are passed in quad registers when using the VFP
|
||
ABI, even if a NEON unit is not present. REGNUM is the index
|
||
of the quad register, in [0, 15]. */
|
||
|
||
static void
|
||
arm_neon_quad_write (struct gdbarch *gdbarch, struct regcache *regcache,
|
||
int regnum, const gdb_byte *buf)
|
||
{
|
||
char name_buf[4];
|
||
gdb_byte reg_buf[8];
|
||
int offset, double_regnum;
|
||
|
||
sprintf (name_buf, "d%d", regnum << 1);
|
||
double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
|
||
strlen (name_buf));
|
||
|
||
/* d0 is always the least significant half of q0. */
|
||
if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
|
||
offset = 8;
|
||
else
|
||
offset = 0;
|
||
|
||
regcache_raw_write (regcache, double_regnum, buf + offset);
|
||
offset = 8 - offset;
|
||
regcache_raw_write (regcache, double_regnum + 1, buf + offset);
|
||
}
|
||
|
||
static void
|
||
arm_pseudo_write (struct gdbarch *gdbarch, struct regcache *regcache,
|
||
int regnum, const gdb_byte *buf)
|
||
{
|
||
const int num_regs = gdbarch_num_regs (gdbarch);
|
||
char name_buf[4];
|
||
gdb_byte reg_buf[8];
|
||
int offset, double_regnum;
|
||
|
||
gdb_assert (regnum >= num_regs);
|
||
regnum -= num_regs;
|
||
|
||
if (gdbarch_tdep (gdbarch)->have_neon_pseudos && regnum >= 32 && regnum < 48)
|
||
/* Quad-precision register. */
|
||
arm_neon_quad_write (gdbarch, regcache, regnum - 32, buf);
|
||
else
|
||
{
|
||
/* Single-precision register. */
|
||
gdb_assert (regnum < 32);
|
||
|
||
/* s0 is always the least significant half of d0. */
|
||
if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
|
||
offset = (regnum & 1) ? 0 : 4;
|
||
else
|
||
offset = (regnum & 1) ? 4 : 0;
|
||
|
||
sprintf (name_buf, "d%d", regnum >> 1);
|
||
double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
|
||
strlen (name_buf));
|
||
|
||
regcache_raw_read (regcache, double_regnum, reg_buf);
|
||
memcpy (reg_buf + offset, buf, 4);
|
||
regcache_raw_write (regcache, double_regnum, reg_buf);
|
||
}
|
||
}
|
||
|
||
static struct value *
|
||
value_of_arm_user_reg (struct frame_info *frame, const void *baton)
|
||
{
|
||
const int *reg_p = baton;
|
||
return value_of_register (*reg_p, frame);
|
||
}
|
||
|
||
static enum gdb_osabi
|
||
arm_elf_osabi_sniffer (bfd *abfd)
|
||
{
|
||
unsigned int elfosabi;
|
||
enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
|
||
|
||
elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
|
||
|
||
if (elfosabi == ELFOSABI_ARM)
|
||
/* GNU tools use this value. Check note sections in this case,
|
||
as well. */
|
||
bfd_map_over_sections (abfd,
|
||
generic_elf_osabi_sniff_abi_tag_sections,
|
||
&osabi);
|
||
|
||
/* Anything else will be handled by the generic ELF sniffer. */
|
||
return osabi;
|
||
}
|
||
|
||
|
||
/* Initialize the current architecture based on INFO. If possible,
|
||
re-use an architecture from ARCHES, which is a list of
|
||
architectures already created during this debugging session.
|
||
|
||
Called e.g. at program startup, when reading a core file, and when
|
||
reading a binary file. */
|
||
|
||
static struct gdbarch *
|
||
arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
|
||
{
|
||
struct gdbarch_tdep *tdep;
|
||
struct gdbarch *gdbarch;
|
||
struct gdbarch_list *best_arch;
|
||
enum arm_abi_kind arm_abi = arm_abi_global;
|
||
enum arm_float_model fp_model = arm_fp_model;
|
||
struct tdesc_arch_data *tdesc_data = NULL;
|
||
int i;
|
||
int have_vfp_registers = 0, have_vfp_pseudos = 0, have_neon_pseudos = 0;
|
||
int have_neon = 0;
|
||
int have_fpa_registers = 1;
|
||
|
||
/* Check any target description for validity. */
|
||
if (tdesc_has_registers (info.target_desc))
|
||
{
|
||
/* For most registers we require GDB's default names; but also allow
|
||
the numeric names for sp / lr / pc, as a convenience. */
|
||
static const char *const arm_sp_names[] = { "r13", "sp", NULL };
|
||
static const char *const arm_lr_names[] = { "r14", "lr", NULL };
|
||
static const char *const arm_pc_names[] = { "r15", "pc", NULL };
|
||
|
||
const struct tdesc_feature *feature;
|
||
int valid_p;
|
||
|
||
feature = tdesc_find_feature (info.target_desc,
|
||
"org.gnu.gdb.arm.core");
|
||
if (feature == NULL)
|
||
return NULL;
|
||
|
||
tdesc_data = tdesc_data_alloc ();
|
||
|
||
valid_p = 1;
|
||
for (i = 0; i < ARM_SP_REGNUM; i++)
|
||
valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
|
||
arm_register_names[i]);
|
||
valid_p &= tdesc_numbered_register_choices (feature, tdesc_data,
|
||
ARM_SP_REGNUM,
|
||
arm_sp_names);
|
||
valid_p &= tdesc_numbered_register_choices (feature, tdesc_data,
|
||
ARM_LR_REGNUM,
|
||
arm_lr_names);
|
||
valid_p &= tdesc_numbered_register_choices (feature, tdesc_data,
|
||
ARM_PC_REGNUM,
|
||
arm_pc_names);
|
||
valid_p &= tdesc_numbered_register (feature, tdesc_data,
|
||
ARM_PS_REGNUM, "cpsr");
|
||
|
||
if (!valid_p)
|
||
{
|
||
tdesc_data_cleanup (tdesc_data);
|
||
return NULL;
|
||
}
|
||
|
||
feature = tdesc_find_feature (info.target_desc,
|
||
"org.gnu.gdb.arm.fpa");
|
||
if (feature != NULL)
|
||
{
|
||
valid_p = 1;
|
||
for (i = ARM_F0_REGNUM; i <= ARM_FPS_REGNUM; i++)
|
||
valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
|
||
arm_register_names[i]);
|
||
if (!valid_p)
|
||
{
|
||
tdesc_data_cleanup (tdesc_data);
|
||
return NULL;
|
||
}
|
||
}
|
||
else
|
||
have_fpa_registers = 0;
|
||
|
||
feature = tdesc_find_feature (info.target_desc,
|
||
"org.gnu.gdb.xscale.iwmmxt");
|
||
if (feature != NULL)
|
||
{
|
||
static const char *const iwmmxt_names[] = {
|
||
"wR0", "wR1", "wR2", "wR3", "wR4", "wR5", "wR6", "wR7",
|
||
"wR8", "wR9", "wR10", "wR11", "wR12", "wR13", "wR14", "wR15",
|
||
"wCID", "wCon", "wCSSF", "wCASF", "", "", "", "",
|
||
"wCGR0", "wCGR1", "wCGR2", "wCGR3", "", "", "", "",
|
||
};
|
||
|
||
valid_p = 1;
|
||
for (i = ARM_WR0_REGNUM; i <= ARM_WR15_REGNUM; i++)
|
||
valid_p
|
||
&= tdesc_numbered_register (feature, tdesc_data, i,
|
||
iwmmxt_names[i - ARM_WR0_REGNUM]);
|
||
|
||
/* Check for the control registers, but do not fail if they
|
||
are missing. */
|
||
for (i = ARM_WC0_REGNUM; i <= ARM_WCASF_REGNUM; i++)
|
||
tdesc_numbered_register (feature, tdesc_data, i,
|
||
iwmmxt_names[i - ARM_WR0_REGNUM]);
|
||
|
||
for (i = ARM_WCGR0_REGNUM; i <= ARM_WCGR3_REGNUM; i++)
|
||
valid_p
|
||
&= tdesc_numbered_register (feature, tdesc_data, i,
|
||
iwmmxt_names[i - ARM_WR0_REGNUM]);
|
||
|
||
if (!valid_p)
|
||
{
|
||
tdesc_data_cleanup (tdesc_data);
|
||
return NULL;
|
||
}
|
||
}
|
||
|
||
/* If we have a VFP unit, check whether the single precision registers
|
||
are present. If not, then we will synthesize them as pseudo
|
||
registers. */
|
||
feature = tdesc_find_feature (info.target_desc,
|
||
"org.gnu.gdb.arm.vfp");
|
||
if (feature != NULL)
|
||
{
|
||
static const char *const vfp_double_names[] = {
|
||
"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7",
|
||
"d8", "d9", "d10", "d11", "d12", "d13", "d14", "d15",
|
||
"d16", "d17", "d18", "d19", "d20", "d21", "d22", "d23",
|
||
"d24", "d25", "d26", "d27", "d28", "d29", "d30", "d31",
|
||
};
|
||
|
||
/* Require the double precision registers. There must be either
|
||
16 or 32. */
|
||
valid_p = 1;
|
||
for (i = 0; i < 32; i++)
|
||
{
|
||
valid_p &= tdesc_numbered_register (feature, tdesc_data,
|
||
ARM_D0_REGNUM + i,
|
||
vfp_double_names[i]);
|
||
if (!valid_p)
|
||
break;
|
||
}
|
||
|
||
if (!valid_p && i != 16)
|
||
{
|
||
tdesc_data_cleanup (tdesc_data);
|
||
return NULL;
|
||
}
|
||
|
||
if (tdesc_unnumbered_register (feature, "s0") == 0)
|
||
have_vfp_pseudos = 1;
|
||
|
||
have_vfp_registers = 1;
|
||
|
||
/* If we have VFP, also check for NEON. The architecture allows
|
||
NEON without VFP (integer vector operations only), but GDB
|
||
does not support that. */
|
||
feature = tdesc_find_feature (info.target_desc,
|
||
"org.gnu.gdb.arm.neon");
|
||
if (feature != NULL)
|
||
{
|
||
/* NEON requires 32 double-precision registers. */
|
||
if (i != 32)
|
||
{
|
||
tdesc_data_cleanup (tdesc_data);
|
||
return NULL;
|
||
}
|
||
|
||
/* If there are quad registers defined by the stub, use
|
||
their type; otherwise (normally) provide them with
|
||
the default type. */
|
||
if (tdesc_unnumbered_register (feature, "q0") == 0)
|
||
have_neon_pseudos = 1;
|
||
|
||
have_neon = 1;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* If we have an object to base this architecture on, try to determine
|
||
its ABI. */
|
||
|
||
if (arm_abi == ARM_ABI_AUTO && info.abfd != NULL)
|
||
{
|
||
int ei_osabi, e_flags;
|
||
|
||
switch (bfd_get_flavour (info.abfd))
|
||
{
|
||
case bfd_target_aout_flavour:
|
||
/* Assume it's an old APCS-style ABI. */
|
||
arm_abi = ARM_ABI_APCS;
|
||
break;
|
||
|
||
case bfd_target_coff_flavour:
|
||
/* Assume it's an old APCS-style ABI. */
|
||
/* XXX WinCE? */
|
||
arm_abi = ARM_ABI_APCS;
|
||
break;
|
||
|
||
case bfd_target_elf_flavour:
|
||
ei_osabi = elf_elfheader (info.abfd)->e_ident[EI_OSABI];
|
||
e_flags = elf_elfheader (info.abfd)->e_flags;
|
||
|
||
if (ei_osabi == ELFOSABI_ARM)
|
||
{
|
||
/* GNU tools used to use this value, but do not for EABI
|
||
objects. There's nowhere to tag an EABI version
|
||
anyway, so assume APCS. */
|
||
arm_abi = ARM_ABI_APCS;
|
||
}
|
||
else if (ei_osabi == ELFOSABI_NONE)
|
||
{
|
||
int eabi_ver = EF_ARM_EABI_VERSION (e_flags);
|
||
|
||
switch (eabi_ver)
|
||
{
|
||
case EF_ARM_EABI_UNKNOWN:
|
||
/* Assume GNU tools. */
|
||
arm_abi = ARM_ABI_APCS;
|
||
break;
|
||
|
||
case EF_ARM_EABI_VER4:
|
||
case EF_ARM_EABI_VER5:
|
||
arm_abi = ARM_ABI_AAPCS;
|
||
/* EABI binaries default to VFP float ordering.
|
||
They may also contain build attributes that can
|
||
be used to identify if the VFP argument-passing
|
||
ABI is in use. */
|
||
if (fp_model == ARM_FLOAT_AUTO)
|
||
{
|
||
#ifdef HAVE_ELF
|
||
switch (bfd_elf_get_obj_attr_int (info.abfd,
|
||
OBJ_ATTR_PROC,
|
||
Tag_ABI_VFP_args))
|
||
{
|
||
case 0:
|
||
/* "The user intended FP parameter/result
|
||
passing to conform to AAPCS, base
|
||
variant". */
|
||
fp_model = ARM_FLOAT_SOFT_VFP;
|
||
break;
|
||
case 1:
|
||
/* "The user intended FP parameter/result
|
||
passing to conform to AAPCS, VFP
|
||
variant". */
|
||
fp_model = ARM_FLOAT_VFP;
|
||
break;
|
||
case 2:
|
||
/* "The user intended FP parameter/result
|
||
passing to conform to tool chain-specific
|
||
conventions" - we don't know any such
|
||
conventions, so leave it as "auto". */
|
||
break;
|
||
default:
|
||
/* Attribute value not mentioned in the
|
||
October 2008 ABI, so leave it as
|
||
"auto". */
|
||
break;
|
||
}
|
||
#else
|
||
fp_model = ARM_FLOAT_SOFT_VFP;
|
||
#endif
|
||
}
|
||
break;
|
||
|
||
default:
|
||
/* Leave it as "auto". */
|
||
warning (_("unknown ARM EABI version 0x%x"), eabi_ver);
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (fp_model == ARM_FLOAT_AUTO)
|
||
{
|
||
int e_flags = elf_elfheader (info.abfd)->e_flags;
|
||
|
||
switch (e_flags & (EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT))
|
||
{
|
||
case 0:
|
||
/* Leave it as "auto". Strictly speaking this case
|
||
means FPA, but almost nobody uses that now, and
|
||
many toolchains fail to set the appropriate bits
|
||
for the floating-point model they use. */
|
||
break;
|
||
case EF_ARM_SOFT_FLOAT:
|
||
fp_model = ARM_FLOAT_SOFT_FPA;
|
||
break;
|
||
case EF_ARM_VFP_FLOAT:
|
||
fp_model = ARM_FLOAT_VFP;
|
||
break;
|
||
case EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT:
|
||
fp_model = ARM_FLOAT_SOFT_VFP;
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (e_flags & EF_ARM_BE8)
|
||
info.byte_order_for_code = BFD_ENDIAN_LITTLE;
|
||
|
||
break;
|
||
|
||
default:
|
||
/* Leave it as "auto". */
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* If there is already a candidate, use it. */
|
||
for (best_arch = gdbarch_list_lookup_by_info (arches, &info);
|
||
best_arch != NULL;
|
||
best_arch = gdbarch_list_lookup_by_info (best_arch->next, &info))
|
||
{
|
||
if (arm_abi != ARM_ABI_AUTO
|
||
&& arm_abi != gdbarch_tdep (best_arch->gdbarch)->arm_abi)
|
||
continue;
|
||
|
||
if (fp_model != ARM_FLOAT_AUTO
|
||
&& fp_model != gdbarch_tdep (best_arch->gdbarch)->fp_model)
|
||
continue;
|
||
|
||
/* There are various other properties in tdep that we do not
|
||
need to check here: those derived from a target description,
|
||
since gdbarches with a different target description are
|
||
automatically disqualified. */
|
||
|
||
/* Found a match. */
|
||
break;
|
||
}
|
||
|
||
if (best_arch != NULL)
|
||
{
|
||
if (tdesc_data != NULL)
|
||
tdesc_data_cleanup (tdesc_data);
|
||
return best_arch->gdbarch;
|
||
}
|
||
|
||
tdep = xcalloc (1, sizeof (struct gdbarch_tdep));
|
||
gdbarch = gdbarch_alloc (&info, tdep);
|
||
|
||
/* Record additional information about the architecture we are defining.
|
||
These are gdbarch discriminators, like the OSABI. */
|
||
tdep->arm_abi = arm_abi;
|
||
tdep->fp_model = fp_model;
|
||
tdep->have_fpa_registers = have_fpa_registers;
|
||
tdep->have_vfp_registers = have_vfp_registers;
|
||
tdep->have_vfp_pseudos = have_vfp_pseudos;
|
||
tdep->have_neon_pseudos = have_neon_pseudos;
|
||
tdep->have_neon = have_neon;
|
||
|
||
/* Breakpoints. */
|
||
switch (info.byte_order_for_code)
|
||
{
|
||
case BFD_ENDIAN_BIG:
|
||
tdep->arm_breakpoint = arm_default_arm_be_breakpoint;
|
||
tdep->arm_breakpoint_size = sizeof (arm_default_arm_be_breakpoint);
|
||
tdep->thumb_breakpoint = arm_default_thumb_be_breakpoint;
|
||
tdep->thumb_breakpoint_size = sizeof (arm_default_thumb_be_breakpoint);
|
||
|
||
break;
|
||
|
||
case BFD_ENDIAN_LITTLE:
|
||
tdep->arm_breakpoint = arm_default_arm_le_breakpoint;
|
||
tdep->arm_breakpoint_size = sizeof (arm_default_arm_le_breakpoint);
|
||
tdep->thumb_breakpoint = arm_default_thumb_le_breakpoint;
|
||
tdep->thumb_breakpoint_size = sizeof (arm_default_thumb_le_breakpoint);
|
||
|
||
break;
|
||
|
||
default:
|
||
internal_error (__FILE__, __LINE__,
|
||
_("arm_gdbarch_init: bad byte order for float format"));
|
||
}
|
||
|
||
/* On ARM targets char defaults to unsigned. */
|
||
set_gdbarch_char_signed (gdbarch, 0);
|
||
|
||
/* Note: for displaced stepping, this includes the breakpoint, and one word
|
||
of additional scratch space. This setting isn't used for anything beside
|
||
displaced stepping at present. */
|
||
set_gdbarch_max_insn_length (gdbarch, 4 * DISPLACED_MODIFIED_INSNS);
|
||
|
||
/* This should be low enough for everything. */
|
||
tdep->lowest_pc = 0x20;
|
||
tdep->jb_pc = -1; /* Longjump support not enabled by default. */
|
||
|
||
/* The default, for both APCS and AAPCS, is to return small
|
||
structures in registers. */
|
||
tdep->struct_return = reg_struct_return;
|
||
|
||
set_gdbarch_push_dummy_call (gdbarch, arm_push_dummy_call);
|
||
set_gdbarch_frame_align (gdbarch, arm_frame_align);
|
||
|
||
set_gdbarch_write_pc (gdbarch, arm_write_pc);
|
||
|
||
/* Frame handling. */
|
||
set_gdbarch_dummy_id (gdbarch, arm_dummy_id);
|
||
set_gdbarch_unwind_pc (gdbarch, arm_unwind_pc);
|
||
set_gdbarch_unwind_sp (gdbarch, arm_unwind_sp);
|
||
|
||
frame_base_set_default (gdbarch, &arm_normal_base);
|
||
|
||
/* Address manipulation. */
|
||
set_gdbarch_smash_text_address (gdbarch, arm_smash_text_address);
|
||
set_gdbarch_addr_bits_remove (gdbarch, arm_addr_bits_remove);
|
||
|
||
/* Advance PC across function entry code. */
|
||
set_gdbarch_skip_prologue (gdbarch, arm_skip_prologue);
|
||
|
||
/* Skip trampolines. */
|
||
set_gdbarch_skip_trampoline_code (gdbarch, arm_skip_stub);
|
||
|
||
/* The stack grows downward. */
|
||
set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
|
||
|
||
/* Breakpoint manipulation. */
|
||
set_gdbarch_breakpoint_from_pc (gdbarch, arm_breakpoint_from_pc);
|
||
set_gdbarch_remote_breakpoint_from_pc (gdbarch,
|
||
arm_remote_breakpoint_from_pc);
|
||
|
||
/* Information about registers, etc. */
|
||
set_gdbarch_deprecated_fp_regnum (gdbarch, ARM_FP_REGNUM); /* ??? */
|
||
set_gdbarch_sp_regnum (gdbarch, ARM_SP_REGNUM);
|
||
set_gdbarch_pc_regnum (gdbarch, ARM_PC_REGNUM);
|
||
set_gdbarch_num_regs (gdbarch, ARM_NUM_REGS);
|
||
set_gdbarch_register_type (gdbarch, arm_register_type);
|
||
|
||
/* This "info float" is FPA-specific. Use the generic version if we
|
||
do not have FPA. */
|
||
if (gdbarch_tdep (gdbarch)->have_fpa_registers)
|
||
set_gdbarch_print_float_info (gdbarch, arm_print_float_info);
|
||
|
||
/* Internal <-> external register number maps. */
|
||
set_gdbarch_dwarf2_reg_to_regnum (gdbarch, arm_dwarf_reg_to_regnum);
|
||
set_gdbarch_register_sim_regno (gdbarch, arm_register_sim_regno);
|
||
|
||
set_gdbarch_register_name (gdbarch, arm_register_name);
|
||
|
||
/* Returning results. */
|
||
set_gdbarch_return_value (gdbarch, arm_return_value);
|
||
|
||
/* Disassembly. */
|
||
set_gdbarch_print_insn (gdbarch, gdb_print_insn_arm);
|
||
|
||
/* Minsymbol frobbing. */
|
||
set_gdbarch_elf_make_msymbol_special (gdbarch, arm_elf_make_msymbol_special);
|
||
set_gdbarch_coff_make_msymbol_special (gdbarch,
|
||
arm_coff_make_msymbol_special);
|
||
set_gdbarch_record_special_symbol (gdbarch, arm_record_special_symbol);
|
||
|
||
/* Thumb-2 IT block support. */
|
||
set_gdbarch_adjust_breakpoint_address (gdbarch,
|
||
arm_adjust_breakpoint_address);
|
||
|
||
/* Virtual tables. */
|
||
set_gdbarch_vbit_in_delta (gdbarch, 1);
|
||
|
||
/* Hook in the ABI-specific overrides, if they have been registered. */
|
||
gdbarch_init_osabi (info, gdbarch);
|
||
|
||
dwarf2_frame_set_init_reg (gdbarch, arm_dwarf2_frame_init_reg);
|
||
|
||
/* Add some default predicates. */
|
||
frame_unwind_append_unwinder (gdbarch, &arm_stub_unwind);
|
||
dwarf2_append_unwinders (gdbarch);
|
||
frame_unwind_append_unwinder (gdbarch, &arm_prologue_unwind);
|
||
|
||
/* Now we have tuned the configuration, set a few final things,
|
||
based on what the OS ABI has told us. */
|
||
|
||
/* If the ABI is not otherwise marked, assume the old GNU APCS. EABI
|
||
binaries are always marked. */
|
||
if (tdep->arm_abi == ARM_ABI_AUTO)
|
||
tdep->arm_abi = ARM_ABI_APCS;
|
||
|
||
/* We used to default to FPA for generic ARM, but almost nobody
|
||
uses that now, and we now provide a way for the user to force
|
||
the model. So default to the most useful variant. */
|
||
if (tdep->fp_model == ARM_FLOAT_AUTO)
|
||
tdep->fp_model = ARM_FLOAT_SOFT_FPA;
|
||
|
||
if (tdep->jb_pc >= 0)
|
||
set_gdbarch_get_longjmp_target (gdbarch, arm_get_longjmp_target);
|
||
|
||
/* Floating point sizes and format. */
|
||
set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
|
||
if (tdep->fp_model == ARM_FLOAT_SOFT_FPA || tdep->fp_model == ARM_FLOAT_FPA)
|
||
{
|
||
set_gdbarch_double_format
|
||
(gdbarch, floatformats_ieee_double_littlebyte_bigword);
|
||
set_gdbarch_long_double_format
|
||
(gdbarch, floatformats_ieee_double_littlebyte_bigword);
|
||
}
|
||
else
|
||
{
|
||
set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
|
||
set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
|
||
}
|
||
|
||
if (have_vfp_pseudos)
|
||
{
|
||
/* NOTE: These are the only pseudo registers used by
|
||
the ARM target at the moment. If more are added, a
|
||
little more care in numbering will be needed. */
|
||
|
||
int num_pseudos = 32;
|
||
if (have_neon_pseudos)
|
||
num_pseudos += 16;
|
||
set_gdbarch_num_pseudo_regs (gdbarch, num_pseudos);
|
||
set_gdbarch_pseudo_register_read (gdbarch, arm_pseudo_read);
|
||
set_gdbarch_pseudo_register_write (gdbarch, arm_pseudo_write);
|
||
}
|
||
|
||
if (tdesc_data)
|
||
{
|
||
set_tdesc_pseudo_register_name (gdbarch, arm_register_name);
|
||
|
||
tdesc_use_registers (gdbarch, info.target_desc, tdesc_data);
|
||
|
||
/* Override tdesc_register_type to adjust the types of VFP
|
||
registers for NEON. */
|
||
set_gdbarch_register_type (gdbarch, arm_register_type);
|
||
}
|
||
|
||
/* Add standard register aliases. We add aliases even for those
|
||
nanes which are used by the current architecture - it's simpler,
|
||
and does no harm, since nothing ever lists user registers. */
|
||
for (i = 0; i < ARRAY_SIZE (arm_register_aliases); i++)
|
||
user_reg_add (gdbarch, arm_register_aliases[i].name,
|
||
value_of_arm_user_reg, &arm_register_aliases[i].regnum);
|
||
|
||
return gdbarch;
|
||
}
|
||
|
||
static void
|
||
arm_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
if (tdep == NULL)
|
||
return;
|
||
|
||
fprintf_unfiltered (file, _("arm_dump_tdep: Lowest pc = 0x%lx"),
|
||
(unsigned long) tdep->lowest_pc);
|
||
}
|
||
|
||
extern initialize_file_ftype _initialize_arm_tdep; /* -Wmissing-prototypes */
|
||
|
||
void
|
||
_initialize_arm_tdep (void)
|
||
{
|
||
struct ui_file *stb;
|
||
long length;
|
||
struct cmd_list_element *new_set, *new_show;
|
||
const char *setname;
|
||
const char *setdesc;
|
||
const char *const *regnames;
|
||
int numregs, i, j;
|
||
static char *helptext;
|
||
char regdesc[1024], *rdptr = regdesc;
|
||
size_t rest = sizeof (regdesc);
|
||
|
||
gdbarch_register (bfd_arch_arm, arm_gdbarch_init, arm_dump_tdep);
|
||
|
||
arm_objfile_data_key
|
||
= register_objfile_data_with_cleanup (NULL, arm_objfile_data_free);
|
||
|
||
/* Register an ELF OS ABI sniffer for ARM binaries. */
|
||
gdbarch_register_osabi_sniffer (bfd_arch_arm,
|
||
bfd_target_elf_flavour,
|
||
arm_elf_osabi_sniffer);
|
||
|
||
/* Get the number of possible sets of register names defined in opcodes. */
|
||
num_disassembly_options = get_arm_regname_num_options ();
|
||
|
||
/* Add root prefix command for all "set arm"/"show arm" commands. */
|
||
add_prefix_cmd ("arm", no_class, set_arm_command,
|
||
_("Various ARM-specific commands."),
|
||
&setarmcmdlist, "set arm ", 0, &setlist);
|
||
|
||
add_prefix_cmd ("arm", no_class, show_arm_command,
|
||
_("Various ARM-specific commands."),
|
||
&showarmcmdlist, "show arm ", 0, &showlist);
|
||
|
||
/* Sync the opcode insn printer with our register viewer. */
|
||
parse_arm_disassembler_option ("reg-names-std");
|
||
|
||
/* Initialize the array that will be passed to
|
||
add_setshow_enum_cmd(). */
|
||
valid_disassembly_styles
|
||
= xmalloc ((num_disassembly_options + 1) * sizeof (char *));
|
||
for (i = 0; i < num_disassembly_options; i++)
|
||
{
|
||
numregs = get_arm_regnames (i, &setname, &setdesc, ®names);
|
||
valid_disassembly_styles[i] = setname;
|
||
length = snprintf (rdptr, rest, "%s - %s\n", setname, setdesc);
|
||
rdptr += length;
|
||
rest -= length;
|
||
/* When we find the default names, tell the disassembler to use
|
||
them. */
|
||
if (!strcmp (setname, "std"))
|
||
{
|
||
disassembly_style = setname;
|
||
set_arm_regname_option (i);
|
||
}
|
||
}
|
||
/* Mark the end of valid options. */
|
||
valid_disassembly_styles[num_disassembly_options] = NULL;
|
||
|
||
/* Create the help text. */
|
||
stb = mem_fileopen ();
|
||
fprintf_unfiltered (stb, "%s%s%s",
|
||
_("The valid values are:\n"),
|
||
regdesc,
|
||
_("The default is \"std\"."));
|
||
helptext = ui_file_xstrdup (stb, NULL);
|
||
ui_file_delete (stb);
|
||
|
||
add_setshow_enum_cmd("disassembler", no_class,
|
||
valid_disassembly_styles, &disassembly_style,
|
||
_("Set the disassembly style."),
|
||
_("Show the disassembly style."),
|
||
helptext,
|
||
set_disassembly_style_sfunc,
|
||
NULL, /* FIXME: i18n: The disassembly style is \"%s\". */
|
||
&setarmcmdlist, &showarmcmdlist);
|
||
|
||
add_setshow_boolean_cmd ("apcs32", no_class, &arm_apcs_32,
|
||
_("Set usage of ARM 32-bit mode."),
|
||
_("Show usage of ARM 32-bit mode."),
|
||
_("When off, a 26-bit PC will be used."),
|
||
NULL,
|
||
NULL, /* FIXME: i18n: Usage of ARM 32-bit mode is %s. */
|
||
&setarmcmdlist, &showarmcmdlist);
|
||
|
||
/* Add a command to allow the user to force the FPU model. */
|
||
add_setshow_enum_cmd ("fpu", no_class, fp_model_strings, ¤t_fp_model,
|
||
_("Set the floating point type."),
|
||
_("Show the floating point type."),
|
||
_("auto - Determine the FP typefrom the OS-ABI.\n\
|
||
softfpa - Software FP, mixed-endian doubles on little-endian ARMs.\n\
|
||
fpa - FPA co-processor (GCC compiled).\n\
|
||
softvfp - Software FP with pure-endian doubles.\n\
|
||
vfp - VFP co-processor."),
|
||
set_fp_model_sfunc, show_fp_model,
|
||
&setarmcmdlist, &showarmcmdlist);
|
||
|
||
/* Add a command to allow the user to force the ABI. */
|
||
add_setshow_enum_cmd ("abi", class_support, arm_abi_strings, &arm_abi_string,
|
||
_("Set the ABI."),
|
||
_("Show the ABI."),
|
||
NULL, arm_set_abi, arm_show_abi,
|
||
&setarmcmdlist, &showarmcmdlist);
|
||
|
||
/* Add two commands to allow the user to force the assumed
|
||
execution mode. */
|
||
add_setshow_enum_cmd ("fallback-mode", class_support,
|
||
arm_mode_strings, &arm_fallback_mode_string,
|
||
_("Set the mode assumed when symbols are unavailable."),
|
||
_("Show the mode assumed when symbols are unavailable."),
|
||
NULL, NULL, arm_show_fallback_mode,
|
||
&setarmcmdlist, &showarmcmdlist);
|
||
add_setshow_enum_cmd ("force-mode", class_support,
|
||
arm_mode_strings, &arm_force_mode_string,
|
||
_("Set the mode assumed even when symbols are available."),
|
||
_("Show the mode assumed even when symbols are available."),
|
||
NULL, NULL, arm_show_force_mode,
|
||
&setarmcmdlist, &showarmcmdlist);
|
||
|
||
/* Debugging flag. */
|
||
add_setshow_boolean_cmd ("arm", class_maintenance, &arm_debug,
|
||
_("Set ARM debugging."),
|
||
_("Show ARM debugging."),
|
||
_("When on, arm-specific debugging is enabled."),
|
||
NULL,
|
||
NULL, /* FIXME: i18n: "ARM debugging is %s. */
|
||
&setdebuglist, &showdebuglist);
|
||
}
|