mirror of
https://sourceware.org/git/binutils-gdb.git
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1627 lines
46 KiB
C
1627 lines
46 KiB
C
/* Target-dependent code for the Acorn Risc Machine, for GDB, the GNU Debugger.
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Copyright (C) 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1998, 1999
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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 2 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, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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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 "symfile.h"
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#include "gdb_string.h"
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#include "coff/internal.h" /* Internal format of COFF symbols in BFD */
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/*
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The following macros are actually wrong. Neither arm nor thumb can
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or should set the lsb on addr.
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The thumb addresses are mod 2, so (addr & 2) would be a good heuristic
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to use when checking for thumb (see arm_pc_is_thumb() below).
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Unfortunately, something else depends on these (incorrect) macros, so
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fixing them actually breaks gdb. I didn't have time to investigate. Z.R.
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*/
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/* Thumb function addresses are odd (bit 0 is set). Here are some
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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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/* Macros to round N up or down to the next A boundary; A must be
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a power of two. */
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#define ROUND_DOWN(n,a) ((n) & ~((a) - 1))
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#define ROUND_UP(n,a) (((n) + (a) - 1) & ~((a) - 1))
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/* Should call_function allocate stack space for a struct return? */
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/* The system C compiler uses a similar structure return convention to gcc */
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int
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arm_use_struct_convention (gcc_p, type)
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int gcc_p;
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struct type *type;
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{
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return (TYPE_LENGTH (type) > 4);
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}
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int
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arm_frame_chain_valid (chain, thisframe)
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CORE_ADDR chain;
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struct frame_info *thisframe;
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{
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#define LOWEST_PC 0x20 /* the first 0x20 bytes are the trap vectors. */
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return (chain != 0 && (FRAME_SAVED_PC (thisframe) >= LOWEST_PC));
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}
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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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/* Flag set by arm_fix_call_dummy that tells whether the target function
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is a Thumb function. This flag is checked by arm_push_arguments.
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FIXME: Change the PUSH_ARGUMENTS macro (and its use in valops.c) to
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pass the function address as an additional parameter. */
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static int target_is_thumb;
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/* Flag set by arm_fix_call_dummy that tells whether the calling function
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is a Thumb function. This flag is checked by arm_pc_is_thumb
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and arm_call_dummy_breakpoint_offset. */
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static int caller_is_thumb;
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/* Tell if the program counter value in MEMADDR is in a Thumb function. */
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int
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arm_pc_is_thumb (memaddr)
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bfd_vma memaddr;
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{
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struct minimal_symbol * sym;
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CORE_ADDR sp;
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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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/* Thumb function 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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{
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return (MSYMBOL_IS_SPECIAL(sym));
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}
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else
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return 0;
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}
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/* Tell if the program counter value in MEMADDR is in a call dummy that
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is being called from a Thumb function. */
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int
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arm_pc_is_thumb_dummy (memaddr)
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bfd_vma memaddr;
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{
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CORE_ADDR sp = read_sp();
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if (PC_IN_CALL_DUMMY (memaddr, sp, sp+64))
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return caller_is_thumb;
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else
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return 0;
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}
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CORE_ADDR
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arm_addr_bits_remove (val)
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CORE_ADDR val;
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{
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if (arm_pc_is_thumb (val))
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return (val & (arm_apcs_32 ? 0xfffffffe : 0x03fffffe));
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else
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return (val & (arm_apcs_32 ? 0xfffffffc : 0x03fffffc));
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}
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CORE_ADDR
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arm_saved_pc_after_call (frame)
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struct frame_info *frame;
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{
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return ADDR_BITS_REMOVE (read_register (LR_REGNUM));
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}
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/* A typical Thumb prologue looks like this:
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push {r7, lr}
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add sp, sp, #-28
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add r7, sp, #12
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Sometimes the latter instruction may be replaced by:
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mov r7, sp
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*/
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static CORE_ADDR
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thumb_skip_prologue (pc)
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CORE_ADDR pc;
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{
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CORE_ADDR current_pc;
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for (current_pc = pc; current_pc < pc + 20; current_pc += 2)
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{
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unsigned short insn = read_memory_unsigned_integer (current_pc, 2);
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if ( (insn & 0xfe00) != 0xb400 /* push {..., r7, lr} */
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&& (insn & 0xff00) != 0xb000 /* add sp, #simm */
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&& (insn & 0xff00) != 0xaf00 /* add r7, sp, #imm */
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&& insn != 0x466f /* mov r7, sp */
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&& (insn & 0xffc0) != 0x4640) /* mov r0-r7, r8-r15 */
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break;
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}
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return current_pc;
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}
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/* APCS (ARM procedure call standard) defines the following prologue:
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mov ip, sp
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[stmfd sp!, {a1,a2,a3,a4}]
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stmfd sp!, {...,fp,ip,lr,pc}
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[stfe f7, [sp, #-12]!]
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[stfe f6, [sp, #-12]!]
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[stfe f5, [sp, #-12]!]
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[stfe f4, [sp, #-12]!]
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sub fp, ip, #nn // nn == 20 or 4 depending on second ins
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*/
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CORE_ADDR
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arm_skip_prologue (pc)
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CORE_ADDR pc;
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{
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unsigned long inst;
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CORE_ADDR skip_pc;
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CORE_ADDR func_addr, func_end;
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struct symtab_and_line sal;
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/* See what the symbol table says. */
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if (find_pc_partial_function (pc, NULL, & func_addr, & func_end))
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{
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sal = find_pc_line (func_addr, 0);
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if (sal.line != 0 && sal.end < func_end)
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return sal.end;
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}
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/* Check if this is Thumb code. */
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if (arm_pc_is_thumb (pc))
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return thumb_skip_prologue (pc);
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/* Can't find the prologue end in the symbol table, try it the hard way
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by disassembling the instructions. */
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skip_pc = pc;
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inst = read_memory_integer (skip_pc, 4);
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if (inst != 0xe1a0c00d) /* mov ip, sp */
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return pc;
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skip_pc += 4;
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inst = read_memory_integer (skip_pc, 4);
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if ((inst & 0xfffffff0) == 0xe92d0000) /* stmfd sp!,{a1,a2,a3,a4} */
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{
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skip_pc += 4;
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inst = read_memory_integer (skip_pc, 4);
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}
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if ((inst & 0xfffff800) != 0xe92dd800) /* stmfd sp!,{...,fp,ip,lr,pc} */
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return pc;
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skip_pc += 4;
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inst = read_memory_integer (skip_pc, 4);
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/* Any insns after this point may float into the code, if it makes
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for better instruction scheduling, so we skip them only if
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we find them, but still consdier the function to be frame-ful */
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/* We may have either one sfmfd instruction here, or several stfe insns,
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depending on the version of floating point code we support. */
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if ((inst & 0xffbf0fff) == 0xec2d0200) /* sfmfd fn, <cnt>, [sp]! */
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{
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skip_pc += 4;
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inst = read_memory_integer (skip_pc, 4);
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}
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else
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{
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while ((inst & 0xffff8fff) == 0xed6d0103) /* stfe fn, [sp, #-12]! */
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{
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skip_pc += 4;
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inst = read_memory_integer (skip_pc, 4);
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}
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}
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if ((inst & 0xfffff000) == 0xe24cb000) /* sub fp, ip, #nn */
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skip_pc += 4;
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return skip_pc;
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}
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/* Function: thumb_scan_prologue (helper function for arm_scan_prologue)
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This function decodes a Thumb function prologue to determine:
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1) the size of the stack frame
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2) which registers are saved on it
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3) the offsets of saved regs
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4) the offset from the stack pointer to the frame pointer
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This information is stored in the "extra" fields of the frame_info.
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A typical Thumb function prologue might look like this:
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push {r7, lr}
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sub sp, #28,
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add r7, sp, #12
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Which would create this stack frame (offsets relative to FP)
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old SP -> 24 stack parameters
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20 LR
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16 R7
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R7 -> 0 local variables (16 bytes)
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SP -> -12 additional stack space (12 bytes)
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The frame size would thus be 36 bytes, and the frame offset would be
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12 bytes. The frame register is R7. */
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static void
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thumb_scan_prologue (fi)
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struct frame_info * fi;
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{
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CORE_ADDR prologue_start;
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CORE_ADDR prologue_end;
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CORE_ADDR current_pc;
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int saved_reg[16]; /* which register has been copied to register n? */
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int i;
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if (find_pc_partial_function (fi->pc, NULL, & prologue_start, & prologue_end))
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{
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struct symtab_and_line sal = find_pc_line (prologue_start, 0);
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if (sal.line == 0) /* no line info, use current PC */
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prologue_end = fi->pc;
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else if (sal.end < prologue_end) /* next line begins after fn end */
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prologue_end = sal.end; /* (probably means no prologue) */
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}
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else
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prologue_end = prologue_start + 40; /* We're in the boondocks: allow for */
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/* 16 pushes, an add, and "mv fp,sp" */
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prologue_end = min (prologue_end, fi->pc);
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/* Initialize the saved register map. When register H is copied to
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register L, we will put H in saved_reg[L]. */
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for (i = 0; i < 16; i++)
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saved_reg[i] = i;
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/* Search the prologue looking for instructions that set up the
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frame pointer, adjust the stack pointer, and save registers. */
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fi->framesize = 0;
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for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2)
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{
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unsigned short insn;
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int regno;
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int offset;
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insn = read_memory_unsigned_integer (current_pc, 2);
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if ((insn & 0xfe00) == 0xb400) /* push { rlist } */
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{
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/* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says
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whether to save LR (R14). */
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int mask = (insn & 0xff) | ((insn & 0x100) << 6);
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/* Calculate offsets of saved R0-R7 and LR. */
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for (regno = LR_REGNUM; regno >= 0; regno--)
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if (mask & (1 << regno))
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{
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fi->framesize += 4;
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fi->fsr.regs[saved_reg[regno]] = -(fi->framesize);
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saved_reg[regno] = regno; /* reset saved register map */
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}
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}
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else if ((insn & 0xff00) == 0xb000) /* add sp, #simm */
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{
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offset = (insn & 0x7f) << 2; /* get scaled offset */
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if (insn & 0x80) /* is it signed? */
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offset = -offset;
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fi->framesize -= offset;
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}
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else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
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{
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fi->framereg = THUMB_FP_REGNUM;
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fi->frameoffset = (insn & 0xff) << 2; /* get scaled offset */
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}
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else if (insn == 0x466f) /* mov r7, sp */
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{
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fi->framereg = THUMB_FP_REGNUM;
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fi->frameoffset = 0;
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saved_reg[THUMB_FP_REGNUM] = SP_REGNUM;
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}
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else if ((insn & 0xffc0) == 0x4640) /* mov r0-r7, r8-r15 */
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{
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int lo_reg = insn & 7; /* dest. register (r0-r7) */
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int hi_reg = ((insn >> 3) & 7) + 8; /* source register (r8-15) */
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saved_reg[lo_reg] = hi_reg; /* remember hi reg was saved */
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}
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else
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break; /* anything else isn't prologue */
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}
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}
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/* Function: check_prologue_cache
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Check if prologue for this frame's PC has already been scanned.
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If it has, copy the relevant information about that prologue and
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return non-zero. Otherwise do not copy anything and return zero.
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The information saved in the cache includes:
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* the frame register number;
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* the size of the stack frame;
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* the offsets of saved regs (relative to the old SP); and
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* the offset from the stack pointer to the frame pointer
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The cache contains only one entry, since this is adequate
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for the typical sequence of prologue scan requests we get.
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When performing a backtrace, GDB will usually ask to scan
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the same function twice in a row (once to get the frame chain,
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and once to fill in the extra frame information).
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*/
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static struct frame_info prologue_cache;
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static int
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check_prologue_cache (fi)
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struct frame_info * fi;
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{
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int i;
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if (fi->pc == prologue_cache.pc)
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{
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fi->framereg = prologue_cache.framereg;
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fi->framesize = prologue_cache.framesize;
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fi->frameoffset = prologue_cache.frameoffset;
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for (i = 0; i <= NUM_REGS; i++)
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fi->fsr.regs[i] = prologue_cache.fsr.regs[i];
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return 1;
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}
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else
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return 0;
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}
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/* Function: save_prologue_cache
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Copy the prologue information from fi to the prologue cache.
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*/
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static void
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save_prologue_cache (fi)
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struct frame_info * fi;
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{
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int i;
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prologue_cache.pc = fi->pc;
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prologue_cache.framereg = fi->framereg;
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prologue_cache.framesize = fi->framesize;
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prologue_cache.frameoffset = fi->frameoffset;
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for (i = 0; i <= NUM_REGS; i++)
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prologue_cache.fsr.regs[i] = fi->fsr.regs[i];
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}
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/* Function: arm_scan_prologue
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This function decodes an ARM function prologue to determine:
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1) the size of the stack frame
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2) which registers are saved on it
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3) the offsets of saved regs
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4) the offset from the stack pointer to the frame pointer
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This information is stored in the "extra" fields of the frame_info.
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A typical Arm function prologue might look like this:
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mov ip, sp
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stmfd sp!, {fp, ip, lr, pc}
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sub fp, ip, #4
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sub sp, sp, #16
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Which would create this stack frame (offsets relative to FP):
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IP -> 4 (caller's stack)
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FP -> 0 PC (points to address of stmfd instruction + 12 in callee)
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-4 LR (return address in caller)
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-8 IP (copy of caller's SP)
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-12 FP (caller's FP)
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SP -> -28 Local variables
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The frame size would thus be 32 bytes, and the frame offset would be
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28 bytes. */
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static void
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arm_scan_prologue (fi)
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struct frame_info * fi;
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{
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int regno, sp_offset, fp_offset;
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CORE_ADDR prologue_start, prologue_end, current_pc;
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/* Check if this function is already in the cache of frame information. */
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if (check_prologue_cache (fi))
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return;
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/* Assume there is no frame until proven otherwise. */
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fi->framereg = SP_REGNUM;
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fi->framesize = 0;
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fi->frameoffset = 0;
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/* Check for Thumb prologue. */
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if (arm_pc_is_thumb (fi->pc))
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{
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thumb_scan_prologue (fi);
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save_prologue_cache (fi);
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return;
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}
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/* Find the function prologue. If we can't find the function in
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the symbol table, peek in the stack frame to find the PC. */
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if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
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{
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/* Assume the prologue is everything between the first instruction
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in the function and the first source line. */
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struct symtab_and_line sal = find_pc_line (prologue_start, 0);
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if (sal.line == 0) /* no line info, use current PC */
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prologue_end = fi->pc;
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else if (sal.end < prologue_end) /* next line begins after fn end */
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prologue_end = sal.end; /* (probably means no prologue) */
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}
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else
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{
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/* Get address of the stmfd in the prologue of the callee; the saved
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PC is the address of the stmfd + 12. */
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prologue_start = (read_memory_integer (fi->frame, 4) & 0x03fffffc) - 12;
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prologue_end = prologue_start + 40; /* FIXME: should be big enough */
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}
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/* Now search the prologue looking for instructions that set up the
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frame pointer, adjust the stack pointer, and save registers. */
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sp_offset = fp_offset = 0;
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for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 4)
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|
{
|
|
unsigned int insn = read_memory_unsigned_integer (current_pc, 4);
|
|
|
|
if ((insn & 0xffff0000) == 0xe92d0000) /* stmfd sp!, {..., r7, lr} */
|
|
{
|
|
int mask = insn & 0xffff;
|
|
|
|
/* Calculate offsets of saved registers. */
|
|
for (regno = PC_REGNUM; regno >= 0; regno--)
|
|
if (mask & (1 << regno))
|
|
{
|
|
sp_offset -= 4;
|
|
fi->fsr.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->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->fsr.regs[regno] = sp_offset;
|
|
}
|
|
else if (insn == 0xe1a0c00d) /* mov ip, sp */
|
|
continue;
|
|
else
|
|
break; /* not a recognized prologue instruction */
|
|
}
|
|
|
|
/* 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->framesize = -sp_offset;
|
|
fi->frameoffset = fp_offset - sp_offset;
|
|
|
|
save_prologue_cache (fi);
|
|
}
|
|
|
|
|
|
/* Function: find_callers_reg
|
|
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 (fi, regnum)
|
|
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->fsr.regs[regnum] != 0)
|
|
return read_memory_integer (fi->fsr.regs[regnum],
|
|
REGISTER_RAW_SIZE(regnum));
|
|
return read_register (regnum);
|
|
}
|
|
|
|
|
|
/* 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)
|
|
*/
|
|
|
|
CORE_ADDR
|
|
arm_frame_chain (fi)
|
|
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;
|
|
struct frame_info caller_fi;
|
|
int framereg = fi->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. */
|
|
if (arm_pc_is_thumb (caller_pc) != arm_pc_is_thumb (fi->pc))
|
|
{
|
|
memset (& caller_fi, 0, sizeof (caller_fi));
|
|
caller_fi.pc = caller_pc;
|
|
arm_scan_prologue (& caller_fi);
|
|
framereg = caller_fi.framereg;
|
|
}
|
|
|
|
/* 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->framesize;
|
|
}
|
|
|
|
/* Function: init_extra_frame_info
|
|
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. */
|
|
|
|
void
|
|
arm_init_extra_frame_info (fi)
|
|
struct frame_info * fi;
|
|
{
|
|
int reg;
|
|
|
|
if (fi->next)
|
|
fi->pc = FRAME_SAVED_PC (fi->next);
|
|
|
|
memset (fi->fsr.regs, '\000', sizeof fi->fsr.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->framesize = 0;
|
|
fi->frameoffset = 0;
|
|
return;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
arm_scan_prologue (fi);
|
|
|
|
if (!fi->next) /* this is the innermost frame? */
|
|
fi->frame = read_register (fi->framereg);
|
|
else /* not the innermost frame */
|
|
/* If we have an FP, the callee saved it. */
|
|
if (fi->framereg == FP_REGNUM || fi->framereg == THUMB_FP_REGNUM)
|
|
if (fi->next->fsr.regs[fi->framereg] != 0)
|
|
fi->frame = read_memory_integer (fi->next->fsr.regs[fi->framereg],
|
|
4);
|
|
|
|
/* Calculate actual addresses of saved registers using offsets determined
|
|
by arm_scan_prologue. */
|
|
for (reg = 0; reg < NUM_REGS; reg++)
|
|
if (fi->fsr.regs[reg] != 0)
|
|
fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->frameoffset;
|
|
}
|
|
}
|
|
|
|
|
|
/* Function: frame_saved_pc
|
|
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 (fi)
|
|
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
|
|
{
|
|
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 ()
|
|
{
|
|
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_find_saved_regs (fi, regaddr)
|
|
struct frame_info *fi;
|
|
struct frame_saved_regs *regaddr;
|
|
{
|
|
memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs));
|
|
}
|
|
|
|
|
|
void
|
|
arm_push_dummy_frame ()
|
|
{
|
|
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);
|
|
sp = push_word (sp, read_register (PC_REGNUM)); /* FIXME: was PS_REGNUM */
|
|
sp = push_word (sp, old_sp);
|
|
sp = push_word (sp, read_register (FP_REGNUM));
|
|
|
|
for (regnum = 10; regnum >= 0; regnum --)
|
|
sp = push_word (sp, read_register (regnum));
|
|
|
|
write_register (FP_REGNUM, fp);
|
|
write_register (THUMB_FP_REGNUM, fp);
|
|
write_register (SP_REGNUM, sp);
|
|
}
|
|
|
|
/* 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 (dummy, pc, fun, nargs, args, type, gcc_p)
|
|
char * dummy;
|
|
CORE_ADDR pc;
|
|
CORE_ADDR fun;
|
|
int nargs;
|
|
value_ptr * 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 ()
|
|
{
|
|
if (caller_is_thumb)
|
|
return 4;
|
|
else
|
|
return 8;
|
|
}
|
|
|
|
|
|
CORE_ADDR
|
|
arm_push_arguments(nargs, args, sp, struct_return, struct_addr)
|
|
int nargs;
|
|
value_ptr * args;
|
|
CORE_ADDR sp;
|
|
int struct_return;
|
|
CORE_ADDR struct_addr;
|
|
{
|
|
int argreg;
|
|
int float_argreg;
|
|
int argnum;
|
|
int stack_offset;
|
|
struct stack_arg {
|
|
char *val;
|
|
int len;
|
|
int offset;
|
|
};
|
|
struct stack_arg *stack_args =
|
|
(struct stack_arg*)alloca (nargs * sizeof (struct stack_arg));
|
|
int nstack_args = 0;
|
|
|
|
|
|
/* Initialize the integer and float register pointers. */
|
|
argreg = A1_REGNUM;
|
|
float_argreg = F0_REGNUM;
|
|
|
|
/* the struct_return pointer occupies the first parameter-passing reg */
|
|
if (struct_return)
|
|
write_register (argreg++, struct_addr);
|
|
|
|
/* The offset onto the stack at which we will start copying parameters
|
|
(after the registers are used up) begins at 16 in the old ABI.
|
|
This leaves room for the "home" area for register parameters. */
|
|
stack_offset = REGISTER_SIZE * 4;
|
|
|
|
/* Process args from left to right. Store as many as allowed in
|
|
registers, save the rest to be pushed on the stack */
|
|
for(argnum = 0; argnum < nargs; argnum++)
|
|
{
|
|
char * val;
|
|
value_ptr arg = args[argnum];
|
|
struct type * arg_type = check_typedef (VALUE_TYPE (arg));
|
|
struct type * target_type = TYPE_TARGET_TYPE (arg_type);
|
|
int len = TYPE_LENGTH (arg_type);
|
|
enum type_code typecode = TYPE_CODE (arg_type);
|
|
CORE_ADDR regval;
|
|
int newarg;
|
|
|
|
val = (char *) VALUE_CONTENTS (arg);
|
|
|
|
/* If the argument is a pointer to a function, and it's a Thumb
|
|
function, set the low bit of the pointer. */
|
|
if (typecode == TYPE_CODE_PTR
|
|
&& target_type != NULL
|
|
&& TYPE_CODE (target_type) == TYPE_CODE_FUNC)
|
|
{
|
|
regval = extract_address (val, len);
|
|
if (arm_pc_is_thumb (regval))
|
|
store_address (val, len, MAKE_THUMB_ADDR (regval));
|
|
}
|
|
|
|
#define MAPCS_FLOAT 0 /* --mapcs-float not implemented by the compiler yet */
|
|
#if MAPCS_FLOAT
|
|
/* Up to four floating point arguments can be passed in floating
|
|
point registers on ARM (not on Thumb). */
|
|
if (typecode == TYPE_CODE_FLT
|
|
&& float_argreg <= ARM_LAST_FP_ARG_REGNUM
|
|
&& !target_is_thumb)
|
|
{
|
|
/* This is a floating point value that fits entirely
|
|
in a single register. */
|
|
regval = extract_address (val, len);
|
|
write_register (float_argreg++, regval);
|
|
}
|
|
else
|
|
#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)
|
|
{
|
|
if (argreg <= ARM_LAST_ARG_REGNUM)
|
|
{
|
|
int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE;
|
|
regval = extract_address (val, partial_len);
|
|
|
|
/* It's a simple argument being passed in a general
|
|
register. */
|
|
write_register (argreg, regval);
|
|
argreg++;
|
|
len -= partial_len;
|
|
val += partial_len;
|
|
}
|
|
else
|
|
{
|
|
/* keep for later pushing */
|
|
stack_args[nstack_args].val = val;
|
|
stack_args[nstack_args++].len = len;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
/* now do the real stack pushing, process args right to left */
|
|
while(nstack_args--)
|
|
{
|
|
sp -= stack_args[nstack_args].len;
|
|
write_memory(sp, stack_args[nstack_args].val,
|
|
stack_args[nstack_args].len);
|
|
}
|
|
|
|
/* Return adjusted stack pointer. */
|
|
return sp;
|
|
}
|
|
|
|
void
|
|
arm_pop_frame ()
|
|
{
|
|
struct frame_info *frame = get_current_frame();
|
|
int regnum;
|
|
|
|
for (regnum = 0; regnum < NUM_REGS; regnum++)
|
|
if (frame->fsr.regs[regnum] != 0)
|
|
write_register (regnum,
|
|
read_memory_integer (frame->fsr.regs[regnum], 4));
|
|
|
|
write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
|
|
write_register (SP_REGNUM, read_register (frame->framereg));
|
|
|
|
flush_cached_frames ();
|
|
}
|
|
|
|
static void
|
|
print_fpu_flags (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 ()
|
|
{
|
|
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);
|
|
}
|
|
|
|
static char *original_register_names[] =
|
|
{ "a1", "a2", "a3", "a4", /* 0 1 2 3 */
|
|
"v1", "v2", "v3", "v4", /* 4 5 6 7 */
|
|
"v5", "v6", "sl", "fp", /* 8 9 10 11 */
|
|
"ip", "sp", "lr", "pc", /* 12 13 14 15 */
|
|
"f0", "f1", "f2", "f3", /* 16 17 18 19 */
|
|
"f4", "f5", "f6", "f7", /* 20 21 22 23 */
|
|
"fps","ps" } /* 24 25 */;
|
|
|
|
/* These names are the ones which gcc emits, and
|
|
I find them less confusing. Toggle between them
|
|
using the `othernames' command. */
|
|
static char *additional_register_names[] =
|
|
{ "r0", "r1", "r2", "r3", /* 0 1 2 3 */
|
|
"r4", "r5", "r6", "r7", /* 4 5 6 7 */
|
|
"r8", "r9", "sl", "fp", /* 8 9 10 11 */
|
|
"ip", "sp", "lr", "pc", /* 12 13 14 15 */
|
|
"f0", "f1", "f2", "f3", /* 16 17 18 19 */
|
|
"f4", "f5", "f6", "f7", /* 20 21 22 23 */
|
|
"fps","ps" } /* 24 25 */;
|
|
|
|
char **arm_register_names = original_register_names;
|
|
|
|
|
|
static void
|
|
arm_othernames ()
|
|
{
|
|
static int toggle;
|
|
arm_register_names = (toggle
|
|
? additional_register_names
|
|
: original_register_names);
|
|
toggle = !toggle;
|
|
}
|
|
|
|
/* FIXME: Fill in with the 'right thing', see asm
|
|
template in arm-convert.s */
|
|
|
|
void
|
|
convert_from_extended (ptr, dbl)
|
|
void * ptr;
|
|
double * dbl;
|
|
{
|
|
*dbl = *(double*)ptr;
|
|
}
|
|
|
|
void
|
|
convert_to_extended (dbl, ptr)
|
|
void * ptr;
|
|
double * dbl;
|
|
{
|
|
*(double*)ptr = *dbl;
|
|
}
|
|
|
|
static int
|
|
condition_true (cond, status_reg)
|
|
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;
|
|
}
|
|
|
|
#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 (inst, carry, pc_val, status_reg)
|
|
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 (val)
|
|
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 (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 (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)
|
|
: 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;
|
|
}
|
|
|
|
#include "bfd-in2.h"
|
|
#include "libcoff.h"
|
|
|
|
static int
|
|
gdb_print_insn_arm (memaddr, info)
|
|
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 == BIG_ENDIAN)
|
|
return print_insn_big_arm (memaddr, info);
|
|
else
|
|
return print_insn_little_arm (memaddr, info);
|
|
}
|
|
|
|
/* Sequence of bytes for breakpoint instruction. */
|
|
#define ARM_LE_BREAKPOINT {0xFE,0xDE,0xFF,0xE7} /* Recognized illegal opcodes */
|
|
#define ARM_BE_BREAKPOINT {0xE7,0xFF,0xDE,0xFE}
|
|
#define THUMB_LE_BREAKPOINT {0xfe,0xdf}
|
|
#define THUMB_BE_BREAKPOINT {0xdf,0xfe}
|
|
|
|
/* The following has been superseded by BREAKPOINT_FOR_PC, but
|
|
is defined merely to keep mem-break.c happy. */
|
|
#define LITTLE_BREAKPOINT ARM_LE_BREAKPOINT
|
|
#define BIG_BREAKPOINT ARM_BE_BREAKPOINT
|
|
|
|
/* This function implements the BREAKPOINT_FROM_PC macro. It uses the program
|
|
counter value to determine whether a 16- 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 pc
|
|
(if necessary) to point to the actual memory location where the
|
|
breakpoint should be inserted. */
|
|
|
|
unsigned char *
|
|
arm_breakpoint_from_pc (pcptr, lenptr)
|
|
CORE_ADDR * pcptr;
|
|
int * lenptr;
|
|
{
|
|
if (arm_pc_is_thumb (*pcptr) || arm_pc_is_thumb_dummy (*pcptr))
|
|
{
|
|
if (TARGET_BYTE_ORDER == BIG_ENDIAN)
|
|
{
|
|
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 == BIG_ENDIAN)
|
|
{
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
/* Return non-zero if the PC is inside a call thunk (aka stub or trampoline).
|
|
This implements the IN_SOLIB_CALL_TRAMPOLINE macro. */
|
|
|
|
int
|
|
arm_in_call_stub (pc, name)
|
|
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 (pc)
|
|
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 */
|
|
}
|
|
|
|
|
|
void
|
|
_initialize_arm_tdep ()
|
|
{
|
|
tm_print_insn = gdb_print_insn_arm;
|
|
|
|
add_com ("othernames", class_obscure, arm_othernames,
|
|
"Switch to the other set of register names.");
|
|
|
|
/* ??? 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);
|
|
|
|
}
|
|
|
|
/* 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);
|
|
}
|