2328 lines
70 KiB
C
2328 lines
70 KiB
C
/* Common target dependent code for GDB on ARM systems.
|
||
Copyright 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1998, 1999, 2000,
|
||
2001, 2002 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 2 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, write to the Free Software
|
||
Foundation, Inc., 59 Temple Place - Suite 330,
|
||
Boston, MA 02111-1307, USA. */
|
||
|
||
#include "defs.h"
|
||
#include "frame.h"
|
||
#include "inferior.h"
|
||
#include "gdbcmd.h"
|
||
#include "gdbcore.h"
|
||
#include "symfile.h"
|
||
#include "gdb_string.h"
|
||
#include "coff/internal.h" /* Internal format of COFF symbols in BFD */
|
||
#include "dis-asm.h" /* For register flavors. */
|
||
#include <ctype.h> /* for isupper () */
|
||
#include "regcache.h"
|
||
#include "doublest.h"
|
||
#include "value.h"
|
||
#include "solib-svr4.h"
|
||
|
||
/* Each OS has a different mechanism for accessing the various
|
||
registers stored in the sigcontext structure.
|
||
|
||
SIGCONTEXT_REGISTER_ADDRESS should be defined to the name (or
|
||
function pointer) which may be used to determine the addresses
|
||
of the various saved registers in the sigcontext structure.
|
||
|
||
For the ARM target, there are three parameters to this function.
|
||
The first is the pc value of the frame under consideration, the
|
||
second the stack pointer of this frame, and the last is the
|
||
register number to fetch.
|
||
|
||
If the tm.h file does not define this macro, then it's assumed that
|
||
no mechanism is needed and we define SIGCONTEXT_REGISTER_ADDRESS to
|
||
be 0.
|
||
|
||
When it comes time to multi-arching this code, see the identically
|
||
named machinery in ia64-tdep.c for an example of how it could be
|
||
done. It should not be necessary to modify the code below where
|
||
this macro is used. */
|
||
|
||
#ifdef SIGCONTEXT_REGISTER_ADDRESS
|
||
#ifndef SIGCONTEXT_REGISTER_ADDRESS_P
|
||
#define SIGCONTEXT_REGISTER_ADDRESS_P() 1
|
||
#endif
|
||
#else
|
||
#define SIGCONTEXT_REGISTER_ADDRESS(SP,PC,REG) 0
|
||
#define SIGCONTEXT_REGISTER_ADDRESS_P() 0
|
||
#endif
|
||
|
||
extern void _initialize_arm_tdep (void);
|
||
|
||
/* Number of different reg name sets (options). */
|
||
static int num_flavor_options;
|
||
|
||
/* We have more registers than the disassembler as gdb can print the value
|
||
of special registers as well.
|
||
The general register names are overwritten by whatever is being used by
|
||
the disassembler at the moment. We also adjust the case of cpsr and fps. */
|
||
|
||
/* Initial value: Register names used in ARM's ISA documentation. */
|
||
static char * arm_register_name_strings[] =
|
||
{"r0", "r1", "r2", "r3", /* 0 1 2 3 */
|
||
"r4", "r5", "r6", "r7", /* 4 5 6 7 */
|
||
"r8", "r9", "r10", "r11", /* 8 9 10 11 */
|
||
"r12", "sp", "lr", "pc", /* 12 13 14 15 */
|
||
"f0", "f1", "f2", "f3", /* 16 17 18 19 */
|
||
"f4", "f5", "f6", "f7", /* 20 21 22 23 */
|
||
"fps", "cpsr" }; /* 24 25 */
|
||
static char **arm_register_names = arm_register_name_strings;
|
||
|
||
/* Valid register name flavors. */
|
||
static const char **valid_flavors;
|
||
|
||
/* Disassembly flavor to use. Default to "std" register names. */
|
||
static const char *disassembly_flavor;
|
||
static int current_option; /* Index to that option in the opcodes table. */
|
||
|
||
/* This is used to keep the bfd arch_info in sync with the disassembly
|
||
flavor. */
|
||
static void set_disassembly_flavor_sfunc(char *, int,
|
||
struct cmd_list_element *);
|
||
static void set_disassembly_flavor (void);
|
||
|
||
static void convert_from_extended (void *ptr, void *dbl);
|
||
|
||
/* Define other aspects of the stack frame. We keep the offsets of
|
||
all saved registers, 'cause we need 'em a lot! We also keep the
|
||
current size of the stack frame, and the offset of the frame
|
||
pointer from the stack pointer (for frameless functions, and when
|
||
we're still in the prologue of a function with a frame) */
|
||
|
||
struct frame_extra_info
|
||
{
|
||
int framesize;
|
||
int frameoffset;
|
||
int framereg;
|
||
};
|
||
|
||
/* Addresses for calling Thumb functions have the bit 0 set.
|
||
Here are some macros to test, set, or clear bit 0 of addresses. */
|
||
#define IS_THUMB_ADDR(addr) ((addr) & 1)
|
||
#define MAKE_THUMB_ADDR(addr) ((addr) | 1)
|
||
#define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1)
|
||
|
||
/* 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. */
|
||
|
||
int
|
||
arm_use_struct_convention (int gcc_p, struct type *type)
|
||
{
|
||
int nRc;
|
||
register enum type_code code;
|
||
|
||
/* 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 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) > REGISTER_SIZE)
|
||
{
|
||
return 1;
|
||
}
|
||
|
||
/* 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
|
||
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 (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;
|
||
}
|
||
|
||
int
|
||
arm_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe)
|
||
{
|
||
return (chain != 0 && (FRAME_SAVED_PC (thisframe) >= LOWEST_PC));
|
||
}
|
||
|
||
/* Set to true if the 32-bit mode is in use. */
|
||
|
||
int arm_apcs_32 = 1;
|
||
|
||
/* Flag set by arm_fix_call_dummy that tells whether the target
|
||
function is a Thumb function. This flag is checked by
|
||
arm_push_arguments. FIXME: Change the PUSH_ARGUMENTS macro (and
|
||
its use in valops.c) to pass the function address as an additional
|
||
parameter. */
|
||
|
||
static int target_is_thumb;
|
||
|
||
/* Flag set by arm_fix_call_dummy that tells whether the calling
|
||
function is a Thumb function. This flag is checked by
|
||
arm_pc_is_thumb and arm_call_dummy_breakpoint_offset. */
|
||
|
||
static int caller_is_thumb;
|
||
|
||
/* Determine if the program counter specified in MEMADDR is in a Thumb
|
||
function. */
|
||
|
||
int
|
||
arm_pc_is_thumb (CORE_ADDR memaddr)
|
||
{
|
||
struct minimal_symbol *sym;
|
||
|
||
/* If bit 0 of the address is set, assume this is a Thumb address. */
|
||
if (IS_THUMB_ADDR (memaddr))
|
||
return 1;
|
||
|
||
/* Thumb functions have a "special" bit set in minimal symbols. */
|
||
sym = lookup_minimal_symbol_by_pc (memaddr);
|
||
if (sym)
|
||
{
|
||
return (MSYMBOL_IS_SPECIAL (sym));
|
||
}
|
||
else
|
||
{
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
/* Determine if the program counter specified in MEMADDR is in a call
|
||
dummy being called from a Thumb function. */
|
||
|
||
int
|
||
arm_pc_is_thumb_dummy (CORE_ADDR memaddr)
|
||
{
|
||
CORE_ADDR sp = read_sp ();
|
||
|
||
/* FIXME: Until we switch for the new call dummy macros, this heuristic
|
||
is the best we can do. We are trying to determine if the pc is on
|
||
the stack, which (hopefully) will only happen in a call dummy.
|
||
We hope the current stack pointer is not so far alway from the dummy
|
||
frame location (true if we have not pushed large data structures or
|
||
gone too many levels deep) and that our 1024 is not enough to consider
|
||
code regions as part of the stack (true for most practical purposes) */
|
||
if (PC_IN_CALL_DUMMY (memaddr, sp, sp + 1024))
|
||
return caller_is_thumb;
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
CORE_ADDR
|
||
arm_addr_bits_remove (CORE_ADDR val)
|
||
{
|
||
if (arm_pc_is_thumb (val))
|
||
return (val & (arm_apcs_32 ? 0xfffffffe : 0x03fffffe));
|
||
else
|
||
return (val & (arm_apcs_32 ? 0xfffffffc : 0x03fffffc));
|
||
}
|
||
|
||
CORE_ADDR
|
||
arm_saved_pc_after_call (struct frame_info *frame)
|
||
{
|
||
return ADDR_BITS_REMOVE (read_register (LR_REGNUM));
|
||
}
|
||
|
||
int
|
||
arm_frameless_function_invocation (struct frame_info *fi)
|
||
{
|
||
CORE_ADDR func_start, after_prologue;
|
||
int frameless;
|
||
|
||
func_start = (get_pc_function_start ((fi)->pc) + FUNCTION_START_OFFSET);
|
||
after_prologue = SKIP_PROLOGUE (func_start);
|
||
|
||
/* There are some frameless functions whose first two instructions
|
||
follow the standard APCS form, in which case after_prologue will
|
||
be func_start + 8. */
|
||
|
||
frameless = (after_prologue < func_start + 12);
|
||
return frameless;
|
||
}
|
||
|
||
/* A typical Thumb prologue looks like this:
|
||
push {r7, lr}
|
||
add sp, sp, #-28
|
||
add r7, sp, #12
|
||
Sometimes the latter instruction may be replaced by:
|
||
mov r7, sp
|
||
|
||
or like this:
|
||
push {r7, lr}
|
||
mov r7, sp
|
||
sub sp, #12
|
||
|
||
or, on tpcs, like this:
|
||
sub sp,#16
|
||
push {r7, lr}
|
||
(many instructions)
|
||
mov r7, sp
|
||
sub sp, #12
|
||
|
||
There is always one instruction of three classes:
|
||
1 - push
|
||
2 - setting of r7
|
||
3 - adjusting of sp
|
||
|
||
When we have found at least one of each class we are done with the prolog.
|
||
Note that the "sub sp, #NN" before the push does not count.
|
||
*/
|
||
|
||
static CORE_ADDR
|
||
thumb_skip_prologue (CORE_ADDR pc, CORE_ADDR func_end)
|
||
{
|
||
CORE_ADDR current_pc;
|
||
int findmask = 0; /* findmask:
|
||
bit 0 - push { rlist }
|
||
bit 1 - mov r7, sp OR add r7, sp, #imm (setting of r7)
|
||
bit 2 - sub sp, #simm OR add sp, #simm (adjusting of sp)
|
||
*/
|
||
|
||
for (current_pc = pc; current_pc + 2 < func_end && current_pc < pc + 40; current_pc += 2)
|
||
{
|
||
unsigned short insn = read_memory_unsigned_integer (current_pc, 2);
|
||
|
||
if ((insn & 0xfe00) == 0xb400) /* push { rlist } */
|
||
{
|
||
findmask |= 1; /* push found */
|
||
}
|
||
else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR sub sp, #simm */
|
||
{
|
||
if ((findmask & 1) == 0) /* before push ? */
|
||
continue;
|
||
else
|
||
findmask |= 4; /* add/sub sp found */
|
||
}
|
||
else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
|
||
{
|
||
findmask |= 2; /* setting of r7 found */
|
||
}
|
||
else if (insn == 0x466f) /* mov r7, sp */
|
||
{
|
||
findmask |= 2; /* setting of r7 found */
|
||
}
|
||
else if (findmask == (4+2+1))
|
||
{
|
||
break; /* We have found one of each type of prologue instruction */
|
||
}
|
||
else
|
||
continue; /* something in the prolog that we don't care about or some
|
||
instruction from outside the prolog scheduled here for optimization */
|
||
}
|
||
|
||
return current_pc;
|
||
}
|
||
|
||
/* 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 */
|
||
|
||
CORE_ADDR
|
||
arm_skip_prologue (CORE_ADDR pc)
|
||
{
|
||
unsigned long inst;
|
||
CORE_ADDR skip_pc;
|
||
CORE_ADDR func_addr, func_end;
|
||
char *func_name;
|
||
struct symtab_and_line sal;
|
||
|
||
/* See what the symbol table says. */
|
||
|
||
if (find_pc_partial_function (pc, &func_name, &func_addr, &func_end))
|
||
{
|
||
struct symbol *sym;
|
||
|
||
/* Found a function. */
|
||
sym = lookup_symbol (func_name, NULL, VAR_NAMESPACE, NULL, NULL);
|
||
if (sym && SYMBOL_LANGUAGE (sym) != language_asm)
|
||
{
|
||
/* Don't use this trick for assembly source files. */
|
||
sal = find_pc_line (func_addr, 0);
|
||
if ((sal.line != 0) && (sal.end < func_end))
|
||
return sal.end;
|
||
}
|
||
}
|
||
|
||
/* Check if this is Thumb code. */
|
||
if (arm_pc_is_thumb (pc))
|
||
return thumb_skip_prologue (pc, func_end);
|
||
|
||
/* Can't find the prologue end in the symbol table, try it the hard way
|
||
by disassembling the instructions. */
|
||
skip_pc = pc;
|
||
inst = read_memory_integer (skip_pc, 4);
|
||
if (inst != 0xe1a0c00d) /* mov ip, sp */
|
||
return pc;
|
||
|
||
skip_pc += 4;
|
||
inst = read_memory_integer (skip_pc, 4);
|
||
if ((inst & 0xfffffff0) == 0xe92d0000) /* stmfd sp!,{a1,a2,a3,a4} */
|
||
{
|
||
skip_pc += 4;
|
||
inst = read_memory_integer (skip_pc, 4);
|
||
}
|
||
|
||
if ((inst & 0xfffff800) != 0xe92dd800) /* stmfd sp!,{...,fp,ip,lr,pc} */
|
||
return pc;
|
||
|
||
skip_pc += 4;
|
||
inst = read_memory_integer (skip_pc, 4);
|
||
|
||
/* 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 consdier 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]! */
|
||
{
|
||
skip_pc += 4;
|
||
inst = read_memory_integer (skip_pc, 4);
|
||
}
|
||
else
|
||
{
|
||
while ((inst & 0xffff8fff) == 0xed6d0103) /* stfe fn, [sp, #-12]! */
|
||
{
|
||
skip_pc += 4;
|
||
inst = read_memory_integer (skip_pc, 4);
|
||
}
|
||
}
|
||
|
||
if ((inst & 0xfffff000) == 0xe24cb000) /* sub fp, ip, #nn */
|
||
skip_pc += 4;
|
||
|
||
return skip_pc;
|
||
}
|
||
/* *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
|
||
This information is stored in the "extra" fields of the frame_info.
|
||
|
||
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 frame_info *fi)
|
||
{
|
||
CORE_ADDR prologue_start;
|
||
CORE_ADDR prologue_end;
|
||
CORE_ADDR current_pc;
|
||
int saved_reg[16]; /* which register has been copied to register n? */
|
||
int findmask = 0; /* findmask:
|
||
bit 0 - push { rlist }
|
||
bit 1 - mov r7, sp OR add r7, sp, #imm (setting of r7)
|
||
bit 2 - sub sp, #simm OR add sp, #simm (adjusting of sp)
|
||
*/
|
||
int i;
|
||
|
||
if (find_pc_partial_function (fi->pc, 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 = fi->pc;
|
||
else if (sal.end < prologue_end) /* next line begins after fn end */
|
||
prologue_end = sal.end; /* (probably means no prologue) */
|
||
}
|
||
else
|
||
prologue_end = prologue_start + 40; /* We're in the boondocks: allow for */
|
||
/* 16 pushes, an add, and "mv fp,sp" */
|
||
|
||
prologue_end = min (prologue_end, fi->pc);
|
||
|
||
/* Initialize the saved register map. When register H is copied to
|
||
register L, we will put H in saved_reg[L]. */
|
||
for (i = 0; i < 16; i++)
|
||
saved_reg[i] = i;
|
||
|
||
/* Search the prologue looking for instructions that set up the
|
||
frame pointer, adjust the stack pointer, and save registers.
|
||
Do this until all basic prolog instructions are found. */
|
||
|
||
fi->extra_info->framesize = 0;
|
||
for (current_pc = prologue_start;
|
||
(current_pc < prologue_end) && ((findmask & 7) != 7);
|
||
current_pc += 2)
|
||
{
|
||
unsigned short insn;
|
||
int regno;
|
||
int offset;
|
||
|
||
insn = read_memory_unsigned_integer (current_pc, 2);
|
||
|
||
if ((insn & 0xfe00) == 0xb400) /* push { rlist } */
|
||
{
|
||
int mask;
|
||
findmask |= 1; /* push found */
|
||
/* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says
|
||
whether to save LR (R14). */
|
||
mask = (insn & 0xff) | ((insn & 0x100) << 6);
|
||
|
||
/* Calculate offsets of saved R0-R7 and LR. */
|
||
for (regno = LR_REGNUM; regno >= 0; regno--)
|
||
if (mask & (1 << regno))
|
||
{
|
||
fi->extra_info->framesize += 4;
|
||
fi->saved_regs[saved_reg[regno]] =
|
||
-(fi->extra_info->framesize);
|
||
saved_reg[regno] = regno; /* reset saved register map */
|
||
}
|
||
}
|
||
else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR sub sp, #simm */
|
||
{
|
||
if ((findmask & 1) == 0) /* before push ? */
|
||
continue;
|
||
else
|
||
findmask |= 4; /* add/sub sp found */
|
||
|
||
offset = (insn & 0x7f) << 2; /* get scaled offset */
|
||
if (insn & 0x80) /* is it signed? (==subtracting) */
|
||
{
|
||
fi->extra_info->frameoffset += offset;
|
||
offset = -offset;
|
||
}
|
||
fi->extra_info->framesize -= offset;
|
||
}
|
||
else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
|
||
{
|
||
findmask |= 2; /* setting of r7 found */
|
||
fi->extra_info->framereg = THUMB_FP_REGNUM;
|
||
/* get scaled offset */
|
||
fi->extra_info->frameoffset = (insn & 0xff) << 2;
|
||
}
|
||
else if (insn == 0x466f) /* mov r7, sp */
|
||
{
|
||
findmask |= 2; /* setting of r7 found */
|
||
fi->extra_info->framereg = THUMB_FP_REGNUM;
|
||
fi->extra_info->frameoffset = 0;
|
||
saved_reg[THUMB_FP_REGNUM] = SP_REGNUM;
|
||
}
|
||
else if ((insn & 0xffc0) == 0x4640) /* mov r0-r7, r8-r15 */
|
||
{
|
||
int lo_reg = insn & 7; /* dest. register (r0-r7) */
|
||
int hi_reg = ((insn >> 3) & 7) + 8; /* source register (r8-15) */
|
||
saved_reg[lo_reg] = hi_reg; /* remember hi reg was saved */
|
||
}
|
||
else
|
||
continue; /* something in the prolog that we don't care about or some
|
||
instruction from outside the prolog scheduled here for optimization */
|
||
}
|
||
}
|
||
|
||
/* Check if prologue for this frame's PC has already been scanned. If
|
||
it has, copy the relevant information about that prologue and
|
||
return non-zero. Otherwise do not copy anything and return zero.
|
||
|
||
The information saved in the cache includes:
|
||
* the frame register number;
|
||
* the size of the stack frame;
|
||
* the offsets of saved regs (relative to the old SP); and
|
||
* the offset from the stack pointer to the frame pointer
|
||
|
||
The cache contains only one entry, since this is adequate for the
|
||
typical sequence of prologue scan requests we get. When performing
|
||
a backtrace, GDB will usually ask to scan the same function twice
|
||
in a row (once to get the frame chain, and once to fill in the
|
||
extra frame information). */
|
||
|
||
static struct frame_info prologue_cache;
|
||
|
||
static int
|
||
check_prologue_cache (struct frame_info *fi)
|
||
{
|
||
int i;
|
||
|
||
if (fi->pc == prologue_cache.pc)
|
||
{
|
||
fi->extra_info->framereg = prologue_cache.extra_info->framereg;
|
||
fi->extra_info->framesize = prologue_cache.extra_info->framesize;
|
||
fi->extra_info->frameoffset = prologue_cache.extra_info->frameoffset;
|
||
for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++)
|
||
fi->saved_regs[i] = prologue_cache.saved_regs[i];
|
||
return 1;
|
||
}
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Copy the prologue information from fi to the prologue cache. */
|
||
|
||
static void
|
||
save_prologue_cache (struct frame_info *fi)
|
||
{
|
||
int i;
|
||
|
||
prologue_cache.pc = fi->pc;
|
||
prologue_cache.extra_info->framereg = fi->extra_info->framereg;
|
||
prologue_cache.extra_info->framesize = fi->extra_info->framesize;
|
||
prologue_cache.extra_info->frameoffset = fi->extra_info->frameoffset;
|
||
|
||
for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++)
|
||
prologue_cache.saved_regs[i] = fi->saved_regs[i];
|
||
}
|
||
|
||
|
||
/* 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 *fi)
|
||
{
|
||
int regno, sp_offset, fp_offset;
|
||
LONGEST return_value;
|
||
CORE_ADDR prologue_start, prologue_end, current_pc;
|
||
|
||
/* Check if this function is already in the cache of frame information. */
|
||
if (check_prologue_cache (fi))
|
||
return;
|
||
|
||
/* Assume there is no frame until proven otherwise. */
|
||
fi->extra_info->framereg = SP_REGNUM;
|
||
fi->extra_info->framesize = 0;
|
||
fi->extra_info->frameoffset = 0;
|
||
|
||
/* Check for Thumb prologue. */
|
||
if (arm_pc_is_thumb (fi->pc))
|
||
{
|
||
thumb_scan_prologue (fi);
|
||
save_prologue_cache (fi);
|
||
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 (fi->pc, 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 = fi->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
|
||
{
|
||
/* Get address of the stmfd in the prologue of the callee; the saved
|
||
PC is the address of the stmfd + 8. */
|
||
if (!safe_read_memory_integer (fi->frame, 4, &return_value))
|
||
return;
|
||
else
|
||
{
|
||
prologue_start = ADDR_BITS_REMOVE (return_value) - 8;
|
||
prologue_end = prologue_start + 64; /* See above. */
|
||
}
|
||
}
|
||
|
||
/* 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 ad"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] */
|
||
|
||
sp_offset = fp_offset = 0;
|
||
|
||
if (read_memory_unsigned_integer (prologue_start, 4)
|
||
== 0xe1a0c00d) /* mov ip, sp */
|
||
current_pc = prologue_start + 4;
|
||
else
|
||
current_pc = prologue_start;
|
||
|
||
for (; current_pc < prologue_end; current_pc += 4)
|
||
{
|
||
unsigned int insn = read_memory_unsigned_integer (current_pc, 4);
|
||
|
||
if ((insn & 0xffff0000) == 0xe92d0000)
|
||
/* stmfd sp!, {..., fp, ip, lr, pc}
|
||
or
|
||
stmfd sp!, {a1, a2, a3, a4} */
|
||
{
|
||
int mask = insn & 0xffff;
|
||
|
||
/* Calculate offsets of saved registers. */
|
||
for (regno = PC_REGNUM; regno >= 0; regno--)
|
||
if (mask & (1 << regno))
|
||
{
|
||
sp_offset -= 4;
|
||
fi->saved_regs[regno] = sp_offset;
|
||
}
|
||
}
|
||
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));
|
||
fp_offset = -imm;
|
||
fi->extra_info->framereg = FP_REGNUM;
|
||
}
|
||
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));
|
||
sp_offset -= imm;
|
||
}
|
||
else if ((insn & 0xffff7fff) == 0xed6d0103) /* stfe f?, [sp, -#c]! */
|
||
{
|
||
sp_offset -= 12;
|
||
regno = F0_REGNUM + ((insn >> 12) & 0x07);
|
||
fi->saved_regs[regno] = sp_offset;
|
||
}
|
||
else if ((insn & 0xffbf0fff) == 0xec2d0200) /* sfmfd f0, 4, [sp!] */
|
||
{
|
||
int n_saved_fp_regs;
|
||
unsigned int fp_start_reg, fp_bound_reg;
|
||
|
||
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 = 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++)
|
||
{
|
||
sp_offset -= 12;
|
||
fi->saved_regs[fp_start_reg++] = sp_offset;
|
||
}
|
||
}
|
||
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 negative of the offset (from the original SP)
|
||
of the last thing thing we pushed on the stack. The frame offset is
|
||
[new FP] - [new SP]. */
|
||
fi->extra_info->framesize = -sp_offset;
|
||
if (fi->extra_info->framereg == FP_REGNUM)
|
||
fi->extra_info->frameoffset = fp_offset - sp_offset;
|
||
else
|
||
fi->extra_info->frameoffset = 0;
|
||
|
||
save_prologue_cache (fi);
|
||
}
|
||
|
||
/* Find REGNUM on the stack. Otherwise, it's in an active register.
|
||
One thing we might want to do here is to check REGNUM against the
|
||
clobber mask, and somehow flag it as invalid if it isn't saved on
|
||
the stack somewhere. This would provide a graceful failure mode
|
||
when trying to get the value of caller-saves registers for an inner
|
||
frame. */
|
||
|
||
static CORE_ADDR
|
||
arm_find_callers_reg (struct frame_info *fi, int regnum)
|
||
{
|
||
for (; fi; fi = fi->next)
|
||
|
||
#if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
|
||
return generic_read_register_dummy (fi->pc, fi->frame, regnum);
|
||
else
|
||
#endif
|
||
if (fi->saved_regs[regnum] != 0)
|
||
return read_memory_integer (fi->saved_regs[regnum],
|
||
REGISTER_RAW_SIZE (regnum));
|
||
return read_register (regnum);
|
||
}
|
||
/* *INDENT-OFF* */
|
||
/* Function: frame_chain
|
||
Given a GDB frame, determine the address of the calling function's frame.
|
||
This will be used to create a new GDB frame struct, and then
|
||
INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
|
||
For ARM, we save the frame size when we initialize the frame_info.
|
||
|
||
The original definition of this function was a macro in tm-arm.h:
|
||
{ In the case of the ARM, the frame's nominal address is the FP value,
|
||
and 12 bytes before comes the saved previous FP value as a 4-byte word. }
|
||
|
||
#define FRAME_CHAIN(thisframe) \
|
||
((thisframe)->pc >= LOWEST_PC ? \
|
||
read_memory_integer ((thisframe)->frame - 12, 4) :\
|
||
0)
|
||
*/
|
||
/* *INDENT-ON* */
|
||
|
||
CORE_ADDR
|
||
arm_frame_chain (struct frame_info *fi)
|
||
{
|
||
#if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */
|
||
CORE_ADDR fn_start, callers_pc, fp;
|
||
|
||
/* is this a dummy frame? */
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
|
||
return fi->frame; /* dummy frame same as caller's frame */
|
||
|
||
/* is caller-of-this a dummy frame? */
|
||
callers_pc = FRAME_SAVED_PC (fi); /* find out who called us: */
|
||
fp = arm_find_callers_reg (fi, FP_REGNUM);
|
||
if (PC_IN_CALL_DUMMY (callers_pc, fp, fp))
|
||
return fp; /* dummy frame's frame may bear no relation to ours */
|
||
|
||
if (find_pc_partial_function (fi->pc, 0, &fn_start, 0))
|
||
if (fn_start == entry_point_address ())
|
||
return 0; /* in _start fn, don't chain further */
|
||
#endif
|
||
CORE_ADDR caller_pc, fn_start;
|
||
int framereg = fi->extra_info->framereg;
|
||
|
||
if (fi->pc < LOWEST_PC)
|
||
return 0;
|
||
|
||
/* If the caller is the startup code, we're at the end of the chain. */
|
||
caller_pc = FRAME_SAVED_PC (fi);
|
||
if (find_pc_partial_function (caller_pc, 0, &fn_start, 0))
|
||
if (fn_start == entry_point_address ())
|
||
return 0;
|
||
|
||
/* If the caller is Thumb and the caller is ARM, or vice versa,
|
||
the frame register of the caller is different from ours.
|
||
So we must scan the prologue of the caller to determine its
|
||
frame register number. */
|
||
/* XXX Fixme, we should try to do this without creating a temporary
|
||
caller_fi. */
|
||
if (arm_pc_is_thumb (caller_pc) != arm_pc_is_thumb (fi->pc))
|
||
{
|
||
struct frame_info caller_fi;
|
||
struct cleanup *old_chain;
|
||
|
||
/* Create a temporary frame suitable for scanning the caller's
|
||
prologue. (Ugh.) */
|
||
memset (&caller_fi, 0, sizeof (caller_fi));
|
||
caller_fi.extra_info = (struct frame_extra_info *)
|
||
xcalloc (1, sizeof (struct frame_extra_info));
|
||
old_chain = make_cleanup (xfree, caller_fi.extra_info);
|
||
caller_fi.saved_regs = (CORE_ADDR *)
|
||
xcalloc (1, SIZEOF_FRAME_SAVED_REGS);
|
||
make_cleanup (xfree, caller_fi.saved_regs);
|
||
|
||
/* Now, scan the prologue and obtain the frame register. */
|
||
caller_fi.pc = caller_pc;
|
||
arm_scan_prologue (&caller_fi);
|
||
framereg = caller_fi.extra_info->framereg;
|
||
|
||
/* Deallocate the storage associated with the temporary frame
|
||
created above. */
|
||
do_cleanups (old_chain);
|
||
}
|
||
|
||
/* If the caller used a frame register, return its value.
|
||
Otherwise, return the caller's stack pointer. */
|
||
if (framereg == FP_REGNUM || framereg == THUMB_FP_REGNUM)
|
||
return arm_find_callers_reg (fi, framereg);
|
||
else
|
||
return fi->frame + fi->extra_info->framesize;
|
||
}
|
||
|
||
/* This function actually figures out the frame address for a given pc
|
||
and sp. This is tricky because we sometimes don't use an explicit
|
||
frame pointer, and the previous stack pointer isn't necessarily
|
||
recorded on the stack. The only reliable way to get this info is
|
||
to examine the prologue. FROMLEAF is a little confusing, it means
|
||
this is the next frame up the chain AFTER a frameless function. If
|
||
this is true, then the frame value for this frame is still in the
|
||
fp register. */
|
||
|
||
void
|
||
arm_init_extra_frame_info (int fromleaf, struct frame_info *fi)
|
||
{
|
||
int reg;
|
||
CORE_ADDR sp;
|
||
|
||
if (fi->saved_regs == NULL)
|
||
frame_saved_regs_zalloc (fi);
|
||
|
||
fi->extra_info = (struct frame_extra_info *)
|
||
frame_obstack_alloc (sizeof (struct frame_extra_info));
|
||
|
||
fi->extra_info->framesize = 0;
|
||
fi->extra_info->frameoffset = 0;
|
||
fi->extra_info->framereg = 0;
|
||
|
||
if (fi->next)
|
||
fi->pc = FRAME_SAVED_PC (fi->next);
|
||
|
||
memset (fi->saved_regs, '\000', sizeof fi->saved_regs);
|
||
|
||
#if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
|
||
{
|
||
/* We need to setup fi->frame here because run_stack_dummy gets it wrong
|
||
by assuming it's always FP. */
|
||
fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM);
|
||
fi->extra_info->framesize = 0;
|
||
fi->extra_info->frameoffset = 0;
|
||
return;
|
||
}
|
||
else
|
||
#endif
|
||
|
||
/* Compute stack pointer for this frame. We use this value for both the
|
||
sigtramp and call dummy cases. */
|
||
if (!fi->next)
|
||
sp = read_sp();
|
||
else
|
||
sp = (fi->next->frame - fi->next->extra_info->frameoffset
|
||
+ fi->next->extra_info->framesize);
|
||
|
||
/* Determine whether or not we're in a sigtramp frame.
|
||
Unfortunately, it isn't sufficient to test
|
||
fi->signal_handler_caller because this value is sometimes set
|
||
after invoking INIT_EXTRA_FRAME_INFO. So we test *both*
|
||
fi->signal_handler_caller and IN_SIGTRAMP to determine if we need
|
||
to use the sigcontext addresses for the saved registers.
|
||
|
||
Note: If an ARM IN_SIGTRAMP method ever needs to compare against
|
||
the name of the function, the code below will have to be changed
|
||
to first fetch the name of the function and then pass this name
|
||
to IN_SIGTRAMP. */
|
||
|
||
if (SIGCONTEXT_REGISTER_ADDRESS_P ()
|
||
&& (fi->signal_handler_caller || IN_SIGTRAMP (fi->pc, (char *)0)))
|
||
{
|
||
for (reg = 0; reg < NUM_REGS; reg++)
|
||
fi->saved_regs[reg] = SIGCONTEXT_REGISTER_ADDRESS (sp, fi->pc, reg);
|
||
|
||
/* FIXME: What about thumb mode? */
|
||
fi->extra_info->framereg = SP_REGNUM;
|
||
fi->frame =
|
||
read_memory_integer (fi->saved_regs[fi->extra_info->framereg],
|
||
REGISTER_RAW_SIZE (fi->extra_info->framereg));
|
||
fi->extra_info->framesize = 0;
|
||
fi->extra_info->frameoffset = 0;
|
||
|
||
}
|
||
else if (PC_IN_CALL_DUMMY (fi->pc, sp, fi->frame))
|
||
{
|
||
CORE_ADDR rp;
|
||
CORE_ADDR callers_sp;
|
||
|
||
/* Set rp point at the high end of the saved registers. */
|
||
rp = fi->frame - REGISTER_SIZE;
|
||
|
||
/* Fill in addresses of saved registers. */
|
||
fi->saved_regs[PS_REGNUM] = rp;
|
||
rp -= REGISTER_RAW_SIZE (PS_REGNUM);
|
||
for (reg = PC_REGNUM; reg >= 0; reg--)
|
||
{
|
||
fi->saved_regs[reg] = rp;
|
||
rp -= REGISTER_RAW_SIZE (reg);
|
||
}
|
||
|
||
callers_sp = read_memory_integer (fi->saved_regs[SP_REGNUM],
|
||
REGISTER_RAW_SIZE (SP_REGNUM));
|
||
fi->extra_info->framereg = FP_REGNUM;
|
||
fi->extra_info->framesize = callers_sp - sp;
|
||
fi->extra_info->frameoffset = fi->frame - sp;
|
||
}
|
||
else
|
||
{
|
||
arm_scan_prologue (fi);
|
||
|
||
if (!fi->next)
|
||
/* this is the innermost frame? */
|
||
fi->frame = read_register (fi->extra_info->framereg);
|
||
else if (fi->extra_info->framereg == FP_REGNUM
|
||
|| fi->extra_info->framereg == THUMB_FP_REGNUM)
|
||
{
|
||
/* not the innermost frame */
|
||
/* If we have an FP, the callee saved it. */
|
||
if (fi->next->saved_regs[fi->extra_info->framereg] != 0)
|
||
fi->frame =
|
||
read_memory_integer (fi->next
|
||
->saved_regs[fi->extra_info->framereg], 4);
|
||
else if (fromleaf)
|
||
/* If we were called by a frameless fn. then our frame is
|
||
still in the frame pointer register on the board... */
|
||
fi->frame = read_fp ();
|
||
}
|
||
|
||
/* Calculate actual addresses of saved registers using offsets
|
||
determined by arm_scan_prologue. */
|
||
for (reg = 0; reg < NUM_REGS; reg++)
|
||
if (fi->saved_regs[reg] != 0)
|
||
fi->saved_regs[reg] += (fi->frame + fi->extra_info->framesize
|
||
- fi->extra_info->frameoffset);
|
||
}
|
||
}
|
||
|
||
|
||
/* Find the caller of this frame. We do this by seeing if LR_REGNUM
|
||
is saved in the stack anywhere, otherwise we get it from the
|
||
registers.
|
||
|
||
The old definition of this function was a macro:
|
||
#define FRAME_SAVED_PC(FRAME) \
|
||
ADDR_BITS_REMOVE (read_memory_integer ((FRAME)->frame - 4, 4)) */
|
||
|
||
CORE_ADDR
|
||
arm_frame_saved_pc (struct frame_info *fi)
|
||
{
|
||
#if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
|
||
return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM);
|
||
else
|
||
#endif
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame - fi->extra_info->frameoffset,
|
||
fi->frame))
|
||
{
|
||
return read_memory_integer (fi->saved_regs[PC_REGNUM],
|
||
REGISTER_RAW_SIZE (PC_REGNUM));
|
||
}
|
||
else
|
||
{
|
||
CORE_ADDR pc = arm_find_callers_reg (fi, LR_REGNUM);
|
||
return IS_THUMB_ADDR (pc) ? UNMAKE_THUMB_ADDR (pc) : pc;
|
||
}
|
||
}
|
||
|
||
/* Return the frame address. On ARM, it is R11; on Thumb it is R7.
|
||
Examine the Program Status Register to decide which state we're in. */
|
||
|
||
CORE_ADDR
|
||
arm_target_read_fp (void)
|
||
{
|
||
if (read_register (PS_REGNUM) & 0x20) /* Bit 5 is Thumb state bit */
|
||
return read_register (THUMB_FP_REGNUM); /* R7 if Thumb */
|
||
else
|
||
return read_register (FP_REGNUM); /* R11 if ARM */
|
||
}
|
||
|
||
/* Calculate the frame offsets of the saved registers (ARM version). */
|
||
|
||
void
|
||
arm_frame_init_saved_regs (struct frame_info *fip)
|
||
{
|
||
|
||
if (fip->saved_regs)
|
||
return;
|
||
|
||
arm_init_extra_frame_info (0, fip);
|
||
}
|
||
|
||
void
|
||
arm_push_dummy_frame (void)
|
||
{
|
||
CORE_ADDR old_sp = read_register (SP_REGNUM);
|
||
CORE_ADDR sp = old_sp;
|
||
CORE_ADDR fp, prologue_start;
|
||
int regnum;
|
||
|
||
/* Push the two dummy prologue instructions in reverse order,
|
||
so that they'll be in the correct low-to-high order in memory. */
|
||
/* sub fp, ip, #4 */
|
||
sp = push_word (sp, 0xe24cb004);
|
||
/* stmdb sp!, {r0-r10, fp, ip, lr, pc} */
|
||
prologue_start = sp = push_word (sp, 0xe92ddfff);
|
||
|
||
/* Push a pointer to the dummy prologue + 12, because when stm
|
||
instruction stores the PC, it stores the address of the stm
|
||
instruction itself plus 12. */
|
||
fp = sp = push_word (sp, prologue_start + 12);
|
||
|
||
/* Push the processor status. */
|
||
sp = push_word (sp, read_register (PS_REGNUM));
|
||
|
||
/* Push all 16 registers starting with r15. */
|
||
for (regnum = PC_REGNUM; regnum >= 0; regnum--)
|
||
sp = push_word (sp, read_register (regnum));
|
||
|
||
/* Update fp (for both Thumb and ARM) and sp. */
|
||
write_register (FP_REGNUM, fp);
|
||
write_register (THUMB_FP_REGNUM, fp);
|
||
write_register (SP_REGNUM, sp);
|
||
}
|
||
|
||
/* CALL_DUMMY_WORDS:
|
||
This sequence of words is the instructions
|
||
|
||
mov lr,pc
|
||
mov pc,r4
|
||
illegal
|
||
|
||
Note this is 12 bytes. */
|
||
|
||
LONGEST arm_call_dummy_words[] =
|
||
{
|
||
0xe1a0e00f, 0xe1a0f004, 0xe7ffdefe
|
||
};
|
||
|
||
/* Fix up the call dummy, based on whether the processor is currently
|
||
in Thumb or ARM mode, and whether the target function is Thumb or
|
||
ARM. There are three different situations requiring three
|
||
different dummies:
|
||
|
||
* ARM calling ARM: uses the call dummy in tm-arm.h, which has already
|
||
been copied into the dummy parameter to this function.
|
||
* ARM calling Thumb: uses the call dummy in tm-arm.h, but with the
|
||
"mov pc,r4" instruction patched to be a "bx r4" instead.
|
||
* Thumb calling anything: uses the Thumb dummy defined below, which
|
||
works for calling both ARM and Thumb functions.
|
||
|
||
All three call dummies expect to receive the target function
|
||
address in R4, with the low bit set if it's a Thumb function. */
|
||
|
||
void
|
||
arm_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
|
||
struct value **args, struct type *type, int gcc_p)
|
||
{
|
||
static short thumb_dummy[4] =
|
||
{
|
||
0xf000, 0xf801, /* bl label */
|
||
0xdf18, /* swi 24 */
|
||
0x4720, /* label: bx r4 */
|
||
};
|
||
static unsigned long arm_bx_r4 = 0xe12fff14; /* bx r4 instruction */
|
||
|
||
/* Set flag indicating whether the current PC is in a Thumb function. */
|
||
caller_is_thumb = arm_pc_is_thumb (read_pc ());
|
||
|
||
/* If the target function is Thumb, set the low bit of the function
|
||
address. And if the CPU is currently in ARM mode, patch the
|
||
second instruction of call dummy to use a BX instruction to
|
||
switch to Thumb mode. */
|
||
target_is_thumb = arm_pc_is_thumb (fun);
|
||
if (target_is_thumb)
|
||
{
|
||
fun |= 1;
|
||
if (!caller_is_thumb)
|
||
store_unsigned_integer (dummy + 4, sizeof (arm_bx_r4), arm_bx_r4);
|
||
}
|
||
|
||
/* If the CPU is currently in Thumb mode, use the Thumb call dummy
|
||
instead of the ARM one that's already been copied. This will
|
||
work for both Thumb and ARM target functions. */
|
||
if (caller_is_thumb)
|
||
{
|
||
int i;
|
||
char *p = dummy;
|
||
int len = sizeof (thumb_dummy) / sizeof (thumb_dummy[0]);
|
||
|
||
for (i = 0; i < len; i++)
|
||
{
|
||
store_unsigned_integer (p, sizeof (thumb_dummy[0]), thumb_dummy[i]);
|
||
p += sizeof (thumb_dummy[0]);
|
||
}
|
||
}
|
||
|
||
/* Put the target address in r4; the call dummy will copy this to
|
||
the PC. */
|
||
write_register (4, fun);
|
||
}
|
||
|
||
/* Return the offset in the call dummy of the instruction that needs
|
||
to have a breakpoint placed on it. This is the offset of the 'swi
|
||
24' instruction, which is no longer actually used, but simply acts
|
||
as a place-holder now.
|
||
|
||
This implements the CALL_DUMMY_BREAK_OFFSET macro. */
|
||
|
||
int
|
||
arm_call_dummy_breakpoint_offset (void)
|
||
{
|
||
if (caller_is_thumb)
|
||
return 4;
|
||
else
|
||
return 8;
|
||
}
|
||
|
||
/* Note: ScottB
|
||
|
||
This function does not support passing parameters using the FPA
|
||
variant of the APCS. It passes any floating point arguments in the
|
||
general registers and/or on the stack. */
|
||
|
||
CORE_ADDR
|
||
arm_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
|
||
int struct_return, CORE_ADDR struct_addr)
|
||
{
|
||
char *fp;
|
||
int argnum, argreg, nstack_size;
|
||
|
||
/* 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_size = -4 * REGISTER_SIZE; /* Some arguments go into A1-A4. */
|
||
if (struct_return) /* The struct address goes in A1. */
|
||
nstack_size += REGISTER_SIZE;
|
||
|
||
/* Walk through the arguments and add their size to nstack_size. */
|
||
for (argnum = 0; argnum < nargs; argnum++)
|
||
{
|
||
int len;
|
||
struct type *arg_type;
|
||
|
||
arg_type = check_typedef (VALUE_TYPE (args[argnum]));
|
||
len = TYPE_LENGTH (arg_type);
|
||
|
||
/* ANSI C code passes float arguments as integers, K&R code
|
||
passes float arguments as doubles. Correct for this here. */
|
||
if (TYPE_CODE_FLT == TYPE_CODE (arg_type) && REGISTER_SIZE == len)
|
||
nstack_size += FP_REGISTER_VIRTUAL_SIZE;
|
||
else
|
||
nstack_size += len;
|
||
}
|
||
|
||
/* Allocate room on the stack, and initialize our stack frame
|
||
pointer. */
|
||
fp = NULL;
|
||
if (nstack_size > 0)
|
||
{
|
||
sp -= nstack_size;
|
||
fp = (char *) sp;
|
||
}
|
||
|
||
/* Initialize the integer argument register pointer. */
|
||
argreg = A1_REGNUM;
|
||
|
||
/* The struct_return pointer occupies the first parameter passing
|
||
register. */
|
||
if (struct_return)
|
||
write_register (argreg++, struct_addr);
|
||
|
||
/* Process arguments from left to right. Store as many as allowed
|
||
in the parameter passing registers (A1-A4), and save the rest on
|
||
the temporary stack. */
|
||
for (argnum = 0; argnum < nargs; argnum++)
|
||
{
|
||
int len;
|
||
char *val;
|
||
CORE_ADDR regval;
|
||
enum type_code typecode;
|
||
struct type *arg_type, *target_type;
|
||
|
||
arg_type = check_typedef (VALUE_TYPE (args[argnum]));
|
||
target_type = TYPE_TARGET_TYPE (arg_type);
|
||
len = TYPE_LENGTH (arg_type);
|
||
typecode = TYPE_CODE (arg_type);
|
||
val = (char *) VALUE_CONTENTS (args[argnum]);
|
||
|
||
/* ANSI C code passes float arguments as integers, K&R code
|
||
passes float arguments as doubles. The .stabs record for
|
||
for ANSI prototype floating point arguments records the
|
||
type as FP_INTEGER, while a K&R style (no prototype)
|
||
.stabs records the type as FP_FLOAT. In this latter case
|
||
the compiler converts the float arguments to double before
|
||
calling the function. */
|
||
if (TYPE_CODE_FLT == typecode && REGISTER_SIZE == len)
|
||
{
|
||
DOUBLEST dblval;
|
||
dblval = extract_floating (val, len);
|
||
len = TARGET_DOUBLE_BIT / TARGET_CHAR_BIT;
|
||
val = alloca (len);
|
||
store_floating (val, len, dblval);
|
||
}
|
||
#if 1
|
||
/* I don't know why this code was disable. The only logical use
|
||
for a function pointer is to call that function, so setting
|
||
the mode bit is perfectly fine. FN */
|
||
/* If the argument is a pointer to a function, and it is a Thumb
|
||
function, set the low bit of the pointer. */
|
||
if (TYPE_CODE_PTR == typecode
|
||
&& NULL != target_type
|
||
&& TYPE_CODE_FUNC == TYPE_CODE (target_type))
|
||
{
|
||
CORE_ADDR regval = extract_address (val, len);
|
||
if (arm_pc_is_thumb (regval))
|
||
store_address (val, len, MAKE_THUMB_ADDR (regval));
|
||
}
|
||
#endif
|
||
/* 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 < REGISTER_SIZE ? len : REGISTER_SIZE;
|
||
|
||
if (argreg <= ARM_LAST_ARG_REGNUM)
|
||
{
|
||
/* It's an argument being passed in a general register. */
|
||
regval = extract_address (val, partial_len);
|
||
write_register (argreg++, regval);
|
||
}
|
||
else
|
||
{
|
||
/* Push the arguments onto the stack. */
|
||
write_memory ((CORE_ADDR) fp, val, REGISTER_SIZE);
|
||
fp += REGISTER_SIZE;
|
||
}
|
||
|
||
len -= partial_len;
|
||
val += partial_len;
|
||
}
|
||
}
|
||
|
||
/* Return adjusted stack pointer. */
|
||
return sp;
|
||
}
|
||
|
||
/* Pop the current frame. So long as the frame info has been initialized
|
||
properly (see arm_init_extra_frame_info), this code works for dummy frames
|
||
as well as regular frames. I.e, there's no need to have a special case
|
||
for dummy frames. */
|
||
void
|
||
arm_pop_frame (void)
|
||
{
|
||
int regnum;
|
||
struct frame_info *frame = get_current_frame ();
|
||
CORE_ADDR old_SP = (frame->frame - frame->extra_info->frameoffset
|
||
+ frame->extra_info->framesize);
|
||
|
||
for (regnum = 0; regnum < NUM_REGS; regnum++)
|
||
if (frame->saved_regs[regnum] != 0)
|
||
write_register (regnum,
|
||
read_memory_integer (frame->saved_regs[regnum],
|
||
REGISTER_RAW_SIZE (regnum)));
|
||
|
||
write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
|
||
write_register (SP_REGNUM, old_SP);
|
||
|
||
flush_cached_frames ();
|
||
}
|
||
|
||
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');
|
||
}
|
||
|
||
void
|
||
arm_float_info (void)
|
||
{
|
||
register unsigned long status = read_register (FPS_REGNUM);
|
||
int type;
|
||
|
||
type = (status >> 24) & 127;
|
||
printf ("%s FPU type %d\n",
|
||
(status & (1 << 31)) ? "Hardware" : "Software",
|
||
type);
|
||
fputs ("mask: ", stdout);
|
||
print_fpu_flags (status >> 16);
|
||
fputs ("flags: ", stdout);
|
||
print_fpu_flags (status);
|
||
}
|
||
|
||
struct type *
|
||
arm_register_type (int regnum)
|
||
{
|
||
if (regnum >= F0_REGNUM && regnum < F0_REGNUM + NUM_FREGS)
|
||
{
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
return builtin_type_arm_ext_big;
|
||
else
|
||
return builtin_type_arm_ext_littlebyte_bigword;
|
||
}
|
||
else
|
||
return builtin_type_int32;
|
||
}
|
||
|
||
/* 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 (void *ptr, void *dbl)
|
||
{
|
||
DOUBLEST d;
|
||
if (TARGET_BYTE_ORDER == 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 (TARGET_DOUBLE_FORMAT, &d, dbl);
|
||
}
|
||
|
||
void
|
||
convert_to_extended (void *dbl, void *ptr)
|
||
{
|
||
DOUBLEST d;
|
||
floatformat_to_doublest (TARGET_DOUBLE_FORMAT, ptr, &d);
|
||
if (TARGET_BYTE_ORDER == 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 (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 : read_register (rs)) & 0xFF;
|
||
}
|
||
else
|
||
shift = bits (inst, 7, 11);
|
||
|
||
res = (rm == 15
|
||
? ((pc_val | (ARM_PC_32 ? 0 : status_reg))
|
||
+ (bit (inst, 4) ? 12 : 8))
|
||
: read_register (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;
|
||
}
|
||
|
||
static CORE_ADDR
|
||
thumb_get_next_pc (CORE_ADDR pc)
|
||
{
|
||
unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */
|
||
unsigned short inst1 = read_memory_integer (pc, 2);
|
||
CORE_ADDR nextpc = pc + 2; /* default is next instruction */
|
||
unsigned long offset;
|
||
|
||
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)) * REGISTER_SIZE;
|
||
sp = read_register (SP_REGNUM);
|
||
nextpc = (CORE_ADDR) read_memory_integer (sp + offset, 4);
|
||
nextpc = ADDR_BITS_REMOVE (nextpc);
|
||
if (nextpc == pc)
|
||
error ("Infinite loop detected");
|
||
}
|
||
else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */
|
||
{
|
||
unsigned long status = read_register (PS_REGNUM);
|
||
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 & 0xf800) == 0xf000) /* long branch with link */
|
||
{
|
||
unsigned short inst2 = read_memory_integer (pc + 2, 2);
|
||
offset = (sbits (inst1, 0, 10) << 12) + (bits (inst2, 0, 10) << 1);
|
||
nextpc = pc_val + offset;
|
||
}
|
||
|
||
return nextpc;
|
||
}
|
||
|
||
CORE_ADDR
|
||
arm_get_next_pc (CORE_ADDR pc)
|
||
{
|
||
unsigned long pc_val;
|
||
unsigned long this_instr;
|
||
unsigned long status;
|
||
CORE_ADDR nextpc;
|
||
|
||
if (arm_pc_is_thumb (pc))
|
||
return thumb_get_next_pc (pc);
|
||
|
||
pc_val = (unsigned long) pc;
|
||
this_instr = read_memory_integer (pc, 4);
|
||
status = read_register (PS_REGNUM);
|
||
nextpc = (CORE_ADDR) (pc_val + 4); /* Default case */
|
||
|
||
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 ("Illegal update to pc in instruction");
|
||
|
||
/* Multiply into PC */
|
||
c = (status & FLAG_C) ? 1 : 0;
|
||
rn = bits (this_instr, 16, 19);
|
||
operand1 = (rn == 15) ? pc_val + 8 : read_register (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 (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;
|
||
}
|
||
nextpc = (CORE_ADDR) ADDR_BITS_REMOVE (result);
|
||
|
||
if (nextpc == pc)
|
||
error ("Infinite loop detected");
|
||
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 ("Illegal update to pc in instruction");
|
||
|
||
/* byte write to PC */
|
||
rn = bits (this_instr, 16, 19);
|
||
base = (rn == 15) ? pc_val + 8 : read_register (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 (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);
|
||
|
||
nextpc = ADDR_BITS_REMOVE (nextpc);
|
||
|
||
if (nextpc == pc)
|
||
error ("Infinite loop detected");
|
||
}
|
||
}
|
||
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 =
|
||
read_register (bits (this_instr, 16, 19));
|
||
nextpc =
|
||
(CORE_ADDR) read_memory_integer ((CORE_ADDR) (rn_val
|
||
+ offset),
|
||
4);
|
||
}
|
||
nextpc = ADDR_BITS_REMOVE (nextpc);
|
||
if (nextpc == pc)
|
||
error ("Infinite loop detected");
|
||
}
|
||
}
|
||
break;
|
||
|
||
case 0xb: /* branch & link */
|
||
case 0xa: /* branch */
|
||
{
|
||
nextpc = BranchDest (pc, this_instr);
|
||
|
||
nextpc = ADDR_BITS_REMOVE (nextpc);
|
||
if (nextpc == pc)
|
||
error ("Infinite loop detected");
|
||
break;
|
||
}
|
||
|
||
case 0xc:
|
||
case 0xd:
|
||
case 0xe: /* coproc ops */
|
||
case 0xf: /* SWI */
|
||
break;
|
||
|
||
default:
|
||
fprintf (stderr, "Bad bit-field extraction\n");
|
||
return (pc);
|
||
}
|
||
}
|
||
|
||
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.
|
||
|
||
single_step is also called just after the inferior stops. If we had
|
||
set up a simulated single-step, we undo our damage. */
|
||
|
||
void
|
||
arm_software_single_step (ignore, insert_bpt)
|
||
int ignore; /* Signal, not needed */
|
||
int insert_bpt;
|
||
{
|
||
static int next_pc; /* State between setting and unsetting. */
|
||
static char break_mem[BREAKPOINT_MAX]; /* Temporary storage for mem@bpt */
|
||
|
||
if (insert_bpt)
|
||
{
|
||
next_pc = arm_get_next_pc (read_register (PC_REGNUM));
|
||
target_insert_breakpoint (next_pc, break_mem);
|
||
}
|
||
else
|
||
target_remove_breakpoint (next_pc, break_mem);
|
||
}
|
||
|
||
#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 (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
return print_insn_big_arm (memaddr, info);
|
||
else
|
||
return print_insn_little_arm (memaddr, info);
|
||
}
|
||
|
||
/* This function implements the BREAKPOINT_FROM_PC macro. It 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. */
|
||
|
||
unsigned char *
|
||
arm_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
|
||
{
|
||
if (arm_pc_is_thumb (*pcptr) || arm_pc_is_thumb_dummy (*pcptr))
|
||
{
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
{
|
||
static char thumb_breakpoint[] = THUMB_BE_BREAKPOINT;
|
||
*pcptr = UNMAKE_THUMB_ADDR (*pcptr);
|
||
*lenptr = sizeof (thumb_breakpoint);
|
||
return thumb_breakpoint;
|
||
}
|
||
else
|
||
{
|
||
static char thumb_breakpoint[] = THUMB_LE_BREAKPOINT;
|
||
*pcptr = UNMAKE_THUMB_ADDR (*pcptr);
|
||
*lenptr = sizeof (thumb_breakpoint);
|
||
return thumb_breakpoint;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
|
||
{
|
||
static char arm_breakpoint[] = ARM_BE_BREAKPOINT;
|
||
*lenptr = sizeof (arm_breakpoint);
|
||
return arm_breakpoint;
|
||
}
|
||
else
|
||
{
|
||
static char arm_breakpoint[] = ARM_LE_BREAKPOINT;
|
||
*lenptr = sizeof (arm_breakpoint);
|
||
return arm_breakpoint;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
void
|
||
arm_extract_return_value (struct type *type,
|
||
char regbuf[REGISTER_BYTES],
|
||
char *valbuf)
|
||
{
|
||
if (TYPE_CODE_FLT == TYPE_CODE (type))
|
||
convert_from_extended (®buf[REGISTER_BYTE (F0_REGNUM)], valbuf);
|
||
else
|
||
memcpy (valbuf, ®buf[REGISTER_BYTE (A1_REGNUM)], TYPE_LENGTH (type));
|
||
}
|
||
|
||
/* Return non-zero if the PC is inside a thumb call thunk. */
|
||
|
||
int
|
||
arm_in_call_stub (CORE_ADDR pc, char *name)
|
||
{
|
||
CORE_ADDR start_addr;
|
||
|
||
/* Find the starting address of the function containing the PC. If
|
||
the caller didn't give us a name, look it up at the same time. */
|
||
if (find_pc_partial_function (pc, name ? NULL : &name, &start_addr, NULL) == 0)
|
||
return 0;
|
||
|
||
return strncmp (name, "_call_via_r", 11) == 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
|
||
_called_via_xx, where x is the register name. The possible names
|
||
are r0-r9, sl, fp, ip, sp, and lr. */
|
||
|
||
CORE_ADDR
|
||
arm_skip_stub (CORE_ADDR pc)
|
||
{
|
||
char *name;
|
||
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;
|
||
|
||
/* Call thunks always start with "_call_via_". */
|
||
if (strncmp (name, "_call_via_", 10) == 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;
|
||
|
||
for (regno = 0; regno <= 14; regno++)
|
||
if (strcmp (&name[10], table[regno]) == 0)
|
||
return read_register (regno);
|
||
}
|
||
|
||
return 0; /* not a stub */
|
||
}
|
||
|
||
/* If the user changes the register disassembly flavor used for info register
|
||
and other commands, we have to also switch the flavor used in opcodes
|
||
for disassembly output.
|
||
This function is run in the set disassembly_flavor command, and does that. */
|
||
|
||
static void
|
||
set_disassembly_flavor_sfunc (char *args, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
set_disassembly_flavor ();
|
||
}
|
||
|
||
/* Return the ARM register name corresponding to register I. */
|
||
char *
|
||
arm_register_name(int i)
|
||
{
|
||
return arm_register_names[i];
|
||
}
|
||
|
||
static void
|
||
set_disassembly_flavor (void)
|
||
{
|
||
const char *setname, *setdesc, **regnames;
|
||
int numregs, j;
|
||
|
||
/* Find the flavor that the user wants in the opcodes table. */
|
||
int current = 0;
|
||
numregs = get_arm_regnames (current, &setname, &setdesc, ®names);
|
||
while ((disassembly_flavor != setname)
|
||
&& (current < num_flavor_options))
|
||
get_arm_regnames (++current, &setname, &setdesc, ®names);
|
||
current_option = current;
|
||
|
||
/* Fill our copy. */
|
||
for (j = 0; j < numregs; j++)
|
||
arm_register_names[j] = (char *) regnames[j];
|
||
|
||
/* Adjust case. */
|
||
if (isupper (*regnames[PC_REGNUM]))
|
||
{
|
||
arm_register_names[FPS_REGNUM] = "FPS";
|
||
arm_register_names[PS_REGNUM] = "CPSR";
|
||
}
|
||
else
|
||
{
|
||
arm_register_names[FPS_REGNUM] = "fps";
|
||
arm_register_names[PS_REGNUM] = "cpsr";
|
||
}
|
||
|
||
/* Synchronize the disassembler. */
|
||
set_arm_regname_option (current);
|
||
}
|
||
|
||
/* arm_othernames implements the "othernames" command. This is kind
|
||
of hacky, and I prefer the set-show disassembly-flavor which is
|
||
also used for the x86 gdb. I will keep this around, however, in
|
||
case anyone is actually using it. */
|
||
|
||
static void
|
||
arm_othernames (char *names, int n)
|
||
{
|
||
/* Circle through the various flavors. */
|
||
current_option = (current_option + 1) % num_flavor_options;
|
||
|
||
disassembly_flavor = valid_flavors[current_option];
|
||
set_disassembly_flavor ();
|
||
}
|
||
|
||
/* Fetch, and possibly build, an appropriate link_map_offsets structure
|
||
for ARM linux targets using the struct offsets defined in <link.h>.
|
||
Note, however, that link.h is not actually referred to in this file.
|
||
Instead, the relevant structs offsets were obtained from examining
|
||
link.h. (We can't refer to link.h from this file because the host
|
||
system won't necessarily have it, or if it does, the structs which
|
||
it defines will refer to the host system, not the target.) */
|
||
|
||
struct link_map_offsets *
|
||
arm_linux_svr4_fetch_link_map_offsets (void)
|
||
{
|
||
static struct link_map_offsets lmo;
|
||
static struct link_map_offsets *lmp = 0;
|
||
|
||
if (lmp == 0)
|
||
{
|
||
lmp = &lmo;
|
||
|
||
lmo.r_debug_size = 8; /* Actual size is 20, but this is all we
|
||
need. */
|
||
|
||
lmo.r_map_offset = 4;
|
||
lmo.r_map_size = 4;
|
||
|
||
lmo.link_map_size = 20; /* Actual size is 552, but this is all we
|
||
need. */
|
||
|
||
lmo.l_addr_offset = 0;
|
||
lmo.l_addr_size = 4;
|
||
|
||
lmo.l_name_offset = 4;
|
||
lmo.l_name_size = 4;
|
||
|
||
lmo.l_next_offset = 12;
|
||
lmo.l_next_size = 4;
|
||
|
||
lmo.l_prev_offset = 16;
|
||
lmo.l_prev_size = 4;
|
||
}
|
||
|
||
return lmp;
|
||
}
|
||
|
||
void
|
||
_initialize_arm_tdep (void)
|
||
{
|
||
struct ui_file *stb;
|
||
long length;
|
||
struct cmd_list_element *new_cmd;
|
||
const char *setname;
|
||
const char *setdesc;
|
||
const char **regnames;
|
||
int numregs, i, j;
|
||
static char *helptext;
|
||
|
||
tm_print_insn = gdb_print_insn_arm;
|
||
|
||
/* Get the number of possible sets of register names defined in opcodes. */
|
||
num_flavor_options = get_arm_regname_num_options ();
|
||
|
||
/* Sync the opcode insn printer with our register viewer: */
|
||
parse_arm_disassembler_option ("reg-names-std");
|
||
|
||
/* Begin creating the help text. */
|
||
stb = mem_fileopen ();
|
||
fprintf_unfiltered (stb, "Set the disassembly flavor.\n\
|
||
The valid values are:\n");
|
||
|
||
/* Initialize the array that will be passed to add_set_enum_cmd(). */
|
||
valid_flavors = xmalloc ((num_flavor_options + 1) * sizeof (char *));
|
||
for (i = 0; i < num_flavor_options; i++)
|
||
{
|
||
numregs = get_arm_regnames (i, &setname, &setdesc, ®names);
|
||
valid_flavors[i] = setname;
|
||
fprintf_unfiltered (stb, "%s - %s\n", setname,
|
||
setdesc);
|
||
/* Copy the default names (if found) and synchronize disassembler. */
|
||
if (!strcmp (setname, "std"))
|
||
{
|
||
disassembly_flavor = setname;
|
||
current_option = i;
|
||
for (j = 0; j < numregs; j++)
|
||
arm_register_names[j] = (char *) regnames[j];
|
||
set_arm_regname_option (i);
|
||
}
|
||
}
|
||
/* Mark the end of valid options. */
|
||
valid_flavors[num_flavor_options] = NULL;
|
||
|
||
/* Finish the creation of the help text. */
|
||
fprintf_unfiltered (stb, "The default is \"std\".");
|
||
helptext = ui_file_xstrdup (stb, &length);
|
||
ui_file_delete (stb);
|
||
|
||
/* Add the disassembly-flavor command */
|
||
new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class,
|
||
valid_flavors,
|
||
&disassembly_flavor,
|
||
helptext,
|
||
&setlist);
|
||
new_cmd->function.sfunc = set_disassembly_flavor_sfunc;
|
||
add_show_from_set (new_cmd, &showlist);
|
||
|
||
/* ??? Maybe this should be a boolean. */
|
||
add_show_from_set (add_set_cmd ("apcs32", no_class,
|
||
var_zinteger, (char *) &arm_apcs_32,
|
||
"Set usage of ARM 32-bit mode.\n", &setlist),
|
||
&showlist);
|
||
|
||
/* Add the deprecated "othernames" command */
|
||
|
||
add_com ("othernames", class_obscure, arm_othernames,
|
||
"Switch to the next set of register names.");
|
||
|
||
/* Fill in the prologue_cache fields. */
|
||
prologue_cache.extra_info = (struct frame_extra_info *)
|
||
xcalloc (1, sizeof (struct frame_extra_info));
|
||
prologue_cache.saved_regs = (CORE_ADDR *)
|
||
xcalloc (1, SIZEOF_FRAME_SAVED_REGS);
|
||
}
|
||
|
||
/* Test whether the coff symbol specific value corresponds to a Thumb
|
||
function. */
|
||
|
||
int
|
||
coff_sym_is_thumb (int val)
|
||
{
|
||
return (val == C_THUMBEXT ||
|
||
val == C_THUMBSTAT ||
|
||
val == C_THUMBEXTFUNC ||
|
||
val == C_THUMBSTATFUNC ||
|
||
val == C_THUMBLABEL);
|
||
}
|