binutils-gdb/gdb/arm-wince-tdep.c

166 lines
4.9 KiB
C

/* Target-dependent code for Windows CE running on ARM processors,
for GDB.
Copyright (C) 2007-2018 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "osabi.h"
#include "gdbcore.h"
#include "target.h"
#include "frame.h"
#include "arch/arm.h"
#include "arm-tdep.h"
#include "windows-tdep.h"
static const gdb_byte arm_wince_le_breakpoint[] = { 0x10, 0x00, 0x00, 0xe6 };
static const gdb_byte arm_wince_thumb_le_breakpoint[] = { 0xfe, 0xdf };
/* Description of the longjmp buffer. */
#define ARM_WINCE_JB_ELEMENT_SIZE INT_REGISTER_SIZE
#define ARM_WINCE_JB_PC 10
static CORE_ADDR
arm_pe_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
ULONGEST indirect;
struct bound_minimal_symbol indsym;
const char *symname;
CORE_ADDR next_pc;
/* The format of an ARM DLL trampoline is:
ldr ip, [pc]
ldr pc, [ip]
.dw __imp_<func>
*/
if (pc == 0
|| read_memory_unsigned_integer (pc + 0, 4, byte_order) != 0xe59fc000
|| read_memory_unsigned_integer (pc + 4, 4, byte_order) != 0xe59cf000)
return 0;
indirect = read_memory_unsigned_integer (pc + 8, 4, byte_order);
if (indirect == 0)
return 0;
indsym = lookup_minimal_symbol_by_pc (indirect);
if (indsym.minsym == NULL)
return 0;
symname = MSYMBOL_LINKAGE_NAME (indsym.minsym);
if (symname == NULL || !startswith (symname, "__imp_"))
return 0;
next_pc = read_memory_unsigned_integer (indirect, 4, byte_order);
if (next_pc != 0)
return next_pc;
/* Check with the default arm gdbarch_skip_trampoline. */
return arm_skip_stub (frame, pc);
}
/* GCC emits a call to __gccmain in the prologue of main.
The function below examines the code pointed at by PC and checks to
see if it corresponds to a call to __gccmain. If so, it returns
the address of the instruction following that call. Otherwise, it
simply returns PC. */
static CORE_ADDR
arm_wince_skip_main_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
ULONGEST this_instr;
this_instr = read_memory_unsigned_integer (pc, 4, byte_order);
/* bl offset <__gccmain> */
if ((this_instr & 0xfff00000) == 0xeb000000)
{
#define sign_extend(V, N) \
(((long) (V) ^ (1L << ((N) - 1))) - (1L << ((N) - 1)))
long offset = sign_extend (this_instr & 0x000fffff, 23) << 2;
CORE_ADDR call_dest = (pc + 8 + offset) & 0xffffffffU;
struct bound_minimal_symbol s = lookup_minimal_symbol_by_pc (call_dest);
if (s.minsym != NULL
&& MSYMBOL_LINKAGE_NAME (s.minsym) != NULL
&& strcmp (MSYMBOL_LINKAGE_NAME (s.minsym), "__gccmain") == 0)
pc += 4;
}
return pc;
}
static void
arm_wince_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
windows_init_abi (info, gdbarch);
tdep->arm_breakpoint = arm_wince_le_breakpoint;
tdep->arm_breakpoint_size = sizeof (arm_wince_le_breakpoint);
tdep->thumb_breakpoint = arm_wince_thumb_le_breakpoint;
tdep->thumb_breakpoint_size = sizeof (arm_wince_thumb_le_breakpoint);
tdep->struct_return = pcc_struct_return;
tdep->fp_model = ARM_FLOAT_SOFT_VFP;
tdep->jb_pc = ARM_WINCE_JB_PC;
tdep->jb_elt_size = ARM_WINCE_JB_ELEMENT_SIZE;
/* On ARM WinCE char defaults to signed. */
set_gdbarch_char_signed (gdbarch, 1);
/* Shared library handling. */
set_gdbarch_skip_trampoline_code (gdbarch, arm_pe_skip_trampoline_code);
/* Single stepping. */
set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
/* Skip call to __gccmain that gcc places in main. */
set_gdbarch_skip_main_prologue (gdbarch, arm_wince_skip_main_prologue);
}
static enum gdb_osabi
arm_wince_osabi_sniffer (bfd *abfd)
{
const char *target_name = bfd_get_target (abfd);
if (strcmp (target_name, "pei-arm-wince-little") == 0)
return GDB_OSABI_WINCE;
return GDB_OSABI_UNKNOWN;
}
void
_initialize_arm_wince_tdep (void)
{
gdbarch_register_osabi_sniffer (bfd_arch_arm, bfd_target_coff_flavour,
arm_wince_osabi_sniffer);
gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_WINCE,
arm_wince_init_abi);
}