685 lines
19 KiB
C
685 lines
19 KiB
C
/* Target dependent code for the Motorola 68000 series.
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Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2000, 2001
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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,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "frame.h"
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#include "symtab.h"
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#include "gdbcore.h"
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#include "value.h"
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#include "gdb_string.h"
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#include "inferior.h"
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#include "regcache.h"
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#define P_LINKL_FP 0x480e
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#define P_LINKW_FP 0x4e56
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#define P_PEA_FP 0x4856
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#define P_MOVL_SP_FP 0x2c4f
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#define P_MOVL 0x207c
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#define P_JSR 0x4eb9
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#define P_BSR 0x61ff
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#define P_LEAL 0x43fb
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#define P_MOVML 0x48ef
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#define P_FMOVM 0xf237
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#define P_TRAP 0x4e40
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/* The only reason this is here is the tm-altos.h reference below. It
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was moved back here from tm-m68k.h. FIXME? */
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extern CORE_ADDR
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altos_skip_prologue (CORE_ADDR pc)
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{
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register int op = read_memory_integer (pc, 2);
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if (op == P_LINKW_FP)
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pc += 4; /* Skip link #word */
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else if (op == P_LINKL_FP)
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pc += 6; /* Skip link #long */
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/* Not sure why branches are here. */
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/* From tm-altos.h */
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else if (op == 0060000)
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pc += 4; /* Skip bra #word */
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else if (op == 00600377)
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pc += 6; /* skip bra #long */
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else if ((op & 0177400) == 0060000)
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pc += 2; /* skip bra #char */
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return pc;
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}
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int
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delta68_in_sigtramp (CORE_ADDR pc, char *name)
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{
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if (name != NULL)
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return strcmp (name, "_sigcode") == 0;
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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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delta68_frame_args_address (struct frame_info *frame_info)
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{
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/* we assume here that the only frameless functions are the system calls
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or other functions who do not put anything on the stack. */
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if (frame_info->signal_handler_caller)
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return frame_info->frame + 12;
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else if (frameless_look_for_prologue (frame_info))
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{
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/* Check for an interrupted system call */
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if (frame_info->next && frame_info->next->signal_handler_caller)
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return frame_info->next->frame + 16;
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else
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return frame_info->frame + 4;
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}
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else
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return frame_info->frame;
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}
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CORE_ADDR
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delta68_frame_saved_pc (struct frame_info *frame_info)
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{
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return read_memory_integer (delta68_frame_args_address (frame_info) + 4, 4);
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}
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/* Return number of args passed to a frame.
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Can return -1, meaning no way to tell. */
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int
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isi_frame_num_args (struct frame_info *fi)
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{
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int val;
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CORE_ADDR pc = FRAME_SAVED_PC (fi);
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int insn = 0177777 & read_memory_integer (pc, 2);
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val = 0;
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if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */
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val = read_memory_integer (pc + 2, 2);
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else if ((insn & 0170777) == 0050217 /* addql #N, sp */
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|| (insn & 0170777) == 0050117) /* addqw */
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{
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val = (insn >> 9) & 7;
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if (val == 0)
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val = 8;
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}
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else if (insn == 0157774) /* addal #WW, sp */
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val = read_memory_integer (pc + 2, 4);
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val >>= 2;
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return val;
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}
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int
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delta68_frame_num_args (struct frame_info *fi)
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{
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int val;
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CORE_ADDR pc = FRAME_SAVED_PC (fi);
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int insn = 0177777 & read_memory_integer (pc, 2);
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val = 0;
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if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */
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val = read_memory_integer (pc + 2, 2);
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else if ((insn & 0170777) == 0050217 /* addql #N, sp */
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|| (insn & 0170777) == 0050117) /* addqw */
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{
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val = (insn >> 9) & 7;
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if (val == 0)
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val = 8;
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}
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else if (insn == 0157774) /* addal #WW, sp */
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val = read_memory_integer (pc + 2, 4);
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val >>= 2;
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return val;
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}
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int
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news_frame_num_args (struct frame_info *fi)
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{
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int val;
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CORE_ADDR pc = FRAME_SAVED_PC (fi);
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int insn = 0177777 & read_memory_integer (pc, 2);
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val = 0;
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if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */
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val = read_memory_integer (pc + 2, 2);
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else if ((insn & 0170777) == 0050217 /* addql #N, sp */
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|| (insn & 0170777) == 0050117) /* addqw */
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{
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val = (insn >> 9) & 7;
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if (val == 0)
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val = 8;
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}
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else if (insn == 0157774) /* addal #WW, sp */
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val = read_memory_integer (pc + 2, 4);
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val >>= 2;
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return val;
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}
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/* Push an empty stack frame, to record the current PC, etc. */
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void
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m68k_push_dummy_frame (void)
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{
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register CORE_ADDR sp = read_register (SP_REGNUM);
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register int regnum;
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char raw_buffer[12];
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sp = push_word (sp, read_register (PC_REGNUM));
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sp = push_word (sp, read_register (FP_REGNUM));
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write_register (FP_REGNUM, sp);
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/* Always save the floating-point registers, whether they exist on
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this target or not. */
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for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)
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{
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read_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12);
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sp = push_bytes (sp, raw_buffer, 12);
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}
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for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)
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{
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sp = push_word (sp, read_register (regnum));
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}
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sp = push_word (sp, read_register (PS_REGNUM));
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write_register (SP_REGNUM, sp);
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}
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/* Discard from the stack the innermost frame,
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restoring all saved registers. */
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void
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m68k_pop_frame (void)
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{
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register struct frame_info *frame = get_current_frame ();
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register CORE_ADDR fp;
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register int regnum;
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struct frame_saved_regs fsr;
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char raw_buffer[12];
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fp = FRAME_FP (frame);
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get_frame_saved_regs (frame, &fsr);
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for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)
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{
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if (fsr.regs[regnum])
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{
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read_memory (fsr.regs[regnum], raw_buffer, 12);
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write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12);
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}
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}
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for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)
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{
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if (fsr.regs[regnum])
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{
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write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));
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}
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}
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if (fsr.regs[PS_REGNUM])
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{
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write_register (PS_REGNUM,
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read_memory_integer (fsr.regs[PS_REGNUM], 4));
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}
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write_register (FP_REGNUM, read_memory_integer (fp, 4));
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write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
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write_register (SP_REGNUM, fp + 8);
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flush_cached_frames ();
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}
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/* Given an ip value corresponding to the start of a function,
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return the ip of the first instruction after the function
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prologue. This is the generic m68k support. Machines which
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require something different can override the SKIP_PROLOGUE
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macro to point elsewhere.
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Some instructions which typically may appear in a function
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prologue include:
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A link instruction, word form:
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link.w %a6,&0 4e56 XXXX
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A link instruction, long form:
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link.l %fp,&F%1 480e XXXX XXXX
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A movm instruction to preserve integer regs:
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movm.l &M%1,(4,%sp) 48ef XXXX XXXX
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A fmovm instruction to preserve float regs:
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fmovm &FPM%1,(FPO%1,%sp) f237 XXXX XXXX XXXX XXXX
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Some profiling setup code (FIXME, not recognized yet):
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lea.l (.L3,%pc),%a1 43fb XXXX XXXX XXXX
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bsr _mcount 61ff XXXX XXXX
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*/
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CORE_ADDR
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m68k_skip_prologue (CORE_ADDR ip)
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{
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register CORE_ADDR limit;
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struct symtab_and_line sal;
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register int op;
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/* Find out if there is a known limit for the extent of the prologue.
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If so, ensure we don't go past it. If not, assume "infinity". */
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sal = find_pc_line (ip, 0);
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limit = (sal.end) ? sal.end : (CORE_ADDR) ~0;
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while (ip < limit)
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{
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op = read_memory_integer (ip, 2);
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op &= 0xFFFF;
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if (op == P_LINKW_FP)
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ip += 4; /* Skip link.w */
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else if (op == P_PEA_FP)
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ip += 2; /* Skip pea %fp */
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else if (op == P_MOVL_SP_FP)
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ip += 2; /* Skip move.l %sp, %fp */
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else if (op == P_LINKL_FP)
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ip += 6; /* Skip link.l */
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else if (op == P_MOVML)
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ip += 6; /* Skip movm.l */
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else if (op == P_FMOVM)
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ip += 10; /* Skip fmovm */
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else
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break; /* Found unknown code, bail out. */
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}
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return (ip);
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}
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void
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m68k_find_saved_regs (struct frame_info *frame_info,
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struct frame_saved_regs *saved_regs)
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{
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register int regnum;
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register int regmask;
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register CORE_ADDR next_addr;
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register CORE_ADDR pc;
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/* First possible address for a pc in a call dummy for this frame. */
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CORE_ADDR possible_call_dummy_start =
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(frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 4 - 8 * 12;
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int nextinsn;
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memset (saved_regs, 0, sizeof (*saved_regs));
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if ((frame_info)->pc >= possible_call_dummy_start
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&& (frame_info)->pc <= (frame_info)->frame)
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{
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/* It is a call dummy. We could just stop now, since we know
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what the call dummy saves and where. But this code proceeds
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to parse the "prologue" which is part of the call dummy.
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This is needlessly complex and confusing. FIXME. */
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next_addr = (frame_info)->frame;
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pc = possible_call_dummy_start;
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}
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else
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{
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pc = get_pc_function_start ((frame_info)->pc);
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nextinsn = read_memory_integer (pc, 2);
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if (P_PEA_FP == nextinsn
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&& P_MOVL_SP_FP == read_memory_integer (pc + 2, 2))
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{
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/* pea %fp
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move.l %sp, %fp */
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next_addr = frame_info->frame;
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pc += 4;
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}
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else if (P_LINKL_FP == nextinsn)
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/* link.l %fp */
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/* Find the address above the saved
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regs using the amount of storage from the link instruction. */
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{
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next_addr = (frame_info)->frame + read_memory_integer (pc + 2, 4);
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pc += 6;
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}
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else if (P_LINKW_FP == nextinsn)
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/* link.w %fp */
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/* Find the address above the saved
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regs using the amount of storage from the link instruction. */
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{
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next_addr = (frame_info)->frame + read_memory_integer (pc + 2, 2);
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pc += 4;
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}
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else
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goto lose;
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/* If have an addal #-n, sp next, adjust next_addr. */
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if ((0177777 & read_memory_integer (pc, 2)) == 0157774)
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next_addr += read_memory_integer (pc += 2, 4), pc += 4;
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}
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for (;;)
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{
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nextinsn = 0xffff & read_memory_integer (pc, 2);
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regmask = read_memory_integer (pc + 2, 2);
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/* fmovemx to -(sp) */
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if (0xf227 == nextinsn && (regmask & 0xff00) == 0xe000)
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{
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/* Regmask's low bit is for register fp7, the first pushed */
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for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1)
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if (regmask & 1)
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saved_regs->regs[regnum] = (next_addr -= 12);
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pc += 4;
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}
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/* fmovemx to (fp + displacement) */
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else if (0171056 == nextinsn && (regmask & 0xff00) == 0xf000)
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{
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register CORE_ADDR addr;
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addr = (frame_info)->frame + read_memory_integer (pc + 4, 2);
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/* Regmask's low bit is for register fp7, the first pushed */
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for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1)
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if (regmask & 1)
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{
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saved_regs->regs[regnum] = addr;
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addr += 12;
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}
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pc += 6;
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}
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/* moveml to (sp) */
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else if (0044327 == nextinsn)
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{
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/* Regmask's low bit is for register 0, the first written */
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for (regnum = 0; regnum < 16; regnum++, regmask >>= 1)
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if (regmask & 1)
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{
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saved_regs->regs[regnum] = next_addr;
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next_addr += 4;
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}
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pc += 4;
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}
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/* moveml to (fp + displacement) */
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else if (0044356 == nextinsn)
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{
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register CORE_ADDR addr;
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addr = (frame_info)->frame + read_memory_integer (pc + 4, 2);
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/* Regmask's low bit is for register 0, the first written */
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for (regnum = 0; regnum < 16; regnum++, regmask >>= 1)
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if (regmask & 1)
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{
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saved_regs->regs[regnum] = addr;
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addr += 4;
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}
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pc += 6;
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}
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/* moveml to -(sp) */
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else if (0044347 == nextinsn)
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{
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/* Regmask's low bit is for register 15, the first pushed */
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for (regnum = 16; --regnum >= 0; regmask >>= 1)
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if (regmask & 1)
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saved_regs->regs[regnum] = (next_addr -= 4);
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pc += 4;
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}
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/* movl r,-(sp) */
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else if (0x2f00 == (0xfff0 & nextinsn))
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{
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regnum = 0xf & nextinsn;
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saved_regs->regs[regnum] = (next_addr -= 4);
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pc += 2;
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}
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/* fmovemx to index of sp */
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else if (0xf236 == nextinsn && (regmask & 0xff00) == 0xf000)
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{
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/* Regmask's low bit is for register fp0, the first written */
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for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1)
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if (regmask & 1)
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{
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saved_regs->regs[regnum] = next_addr;
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next_addr += 12;
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}
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pc += 10;
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}
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/* clrw -(sp); movw ccr,-(sp) */
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else if (0x4267 == nextinsn && 0x42e7 == regmask)
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{
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saved_regs->regs[PS_REGNUM] = (next_addr -= 4);
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pc += 4;
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}
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else
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break;
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}
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lose:;
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saved_regs->regs[SP_REGNUM] = (frame_info)->frame + 8;
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saved_regs->regs[FP_REGNUM] = (frame_info)->frame;
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saved_regs->regs[PC_REGNUM] = (frame_info)->frame + 4;
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#ifdef SIG_SP_FP_OFFSET
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/* Adjust saved SP_REGNUM for fake _sigtramp frames. */
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if (frame_info->signal_handler_caller && frame_info->next)
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saved_regs->regs[SP_REGNUM] = frame_info->next->frame + SIG_SP_FP_OFFSET;
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#endif
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}
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#ifdef USE_PROC_FS /* Target dependent support for /proc */
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#include <sys/procfs.h>
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/* Prototypes for supply_gregset etc. */
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#include "gregset.h"
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/* The /proc interface divides the target machine's register set up into
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two different sets, the general register set (gregset) and the floating
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point register set (fpregset). For each set, there is an ioctl to get
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the current register set and another ioctl to set the current values.
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The actual structure passed through the ioctl interface is, of course,
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naturally machine dependent, and is different for each set of registers.
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For the m68k for example, the general register set is typically defined
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by:
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typedef int gregset_t[18];
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#define R_D0 0
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...
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#define R_PS 17
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and the floating point set by:
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typedef struct fpregset {
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int f_pcr;
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int f_psr;
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||
int f_fpiaddr;
|
||
int f_fpregs[8][3]; (8 regs, 96 bits each)
|
||
} fpregset_t;
|
||
|
||
These routines provide the packing and unpacking of gregset_t and
|
||
fpregset_t formatted data.
|
||
|
||
*/
|
||
|
||
/* Atari SVR4 has R_SR but not R_PS */
|
||
|
||
#if !defined (R_PS) && defined (R_SR)
|
||
#define R_PS R_SR
|
||
#endif
|
||
|
||
/* Given a pointer to a general register set in /proc format (gregset_t *),
|
||
unpack the register contents and supply them as gdb's idea of the current
|
||
register values. */
|
||
|
||
void
|
||
supply_gregset (gregset_t *gregsetp)
|
||
{
|
||
register int regi;
|
||
register greg_t *regp = (greg_t *) gregsetp;
|
||
|
||
for (regi = 0; regi < R_PC; regi++)
|
||
{
|
||
supply_register (regi, (char *) (regp + regi));
|
||
}
|
||
supply_register (PS_REGNUM, (char *) (regp + R_PS));
|
||
supply_register (PC_REGNUM, (char *) (regp + R_PC));
|
||
}
|
||
|
||
void
|
||
fill_gregset (gregset_t *gregsetp, int regno)
|
||
{
|
||
register int regi;
|
||
register greg_t *regp = (greg_t *) gregsetp;
|
||
|
||
for (regi = 0; regi < R_PC; regi++)
|
||
{
|
||
if ((regno == -1) || (regno == regi))
|
||
{
|
||
*(regp + regi) = *(int *) ®isters[REGISTER_BYTE (regi)];
|
||
}
|
||
}
|
||
if ((regno == -1) || (regno == PS_REGNUM))
|
||
{
|
||
*(regp + R_PS) = *(int *) ®isters[REGISTER_BYTE (PS_REGNUM)];
|
||
}
|
||
if ((regno == -1) || (regno == PC_REGNUM))
|
||
{
|
||
*(regp + R_PC) = *(int *) ®isters[REGISTER_BYTE (PC_REGNUM)];
|
||
}
|
||
}
|
||
|
||
#if defined (FP0_REGNUM)
|
||
|
||
/* Given a pointer to a floating point register set in /proc format
|
||
(fpregset_t *), unpack the register contents and supply them as gdb's
|
||
idea of the current floating point register values. */
|
||
|
||
void
|
||
supply_fpregset (fpregset_t *fpregsetp)
|
||
{
|
||
register int regi;
|
||
char *from;
|
||
|
||
for (regi = FP0_REGNUM; regi < FPC_REGNUM; regi++)
|
||
{
|
||
from = (char *) &(fpregsetp->f_fpregs[regi - FP0_REGNUM][0]);
|
||
supply_register (regi, from);
|
||
}
|
||
supply_register (FPC_REGNUM, (char *) &(fpregsetp->f_pcr));
|
||
supply_register (FPS_REGNUM, (char *) &(fpregsetp->f_psr));
|
||
supply_register (FPI_REGNUM, (char *) &(fpregsetp->f_fpiaddr));
|
||
}
|
||
|
||
/* Given a pointer to a floating point register set in /proc format
|
||
(fpregset_t *), update the register specified by REGNO from gdb's idea
|
||
of the current floating point register set. If REGNO is -1, update
|
||
them all. */
|
||
|
||
void
|
||
fill_fpregset (fpregset_t *fpregsetp, int regno)
|
||
{
|
||
int regi;
|
||
char *to;
|
||
char *from;
|
||
|
||
for (regi = FP0_REGNUM; regi < FPC_REGNUM; regi++)
|
||
{
|
||
if ((regno == -1) || (regno == regi))
|
||
{
|
||
from = (char *) ®isters[REGISTER_BYTE (regi)];
|
||
to = (char *) &(fpregsetp->f_fpregs[regi - FP0_REGNUM][0]);
|
||
memcpy (to, from, REGISTER_RAW_SIZE (regi));
|
||
}
|
||
}
|
||
if ((regno == -1) || (regno == FPC_REGNUM))
|
||
{
|
||
fpregsetp->f_pcr = *(int *) ®isters[REGISTER_BYTE (FPC_REGNUM)];
|
||
}
|
||
if ((regno == -1) || (regno == FPS_REGNUM))
|
||
{
|
||
fpregsetp->f_psr = *(int *) ®isters[REGISTER_BYTE (FPS_REGNUM)];
|
||
}
|
||
if ((regno == -1) || (regno == FPI_REGNUM))
|
||
{
|
||
fpregsetp->f_fpiaddr = *(int *) ®isters[REGISTER_BYTE (FPI_REGNUM)];
|
||
}
|
||
}
|
||
|
||
#endif /* defined (FP0_REGNUM) */
|
||
|
||
#endif /* USE_PROC_FS */
|
||
|
||
/* Figure out where the longjmp will land. Slurp the args out of the stack.
|
||
We expect the first arg to be a pointer to the jmp_buf structure from which
|
||
we extract the pc (JB_PC) that we will land at. The pc is copied into PC.
|
||
This routine returns true on success. */
|
||
|
||
/* NOTE: cagney/2000-11-08: For this function to be fully multi-arched
|
||
the macro's JB_PC and JB_ELEMENT_SIZE would need to be moved into
|
||
the ``struct gdbarch_tdep'' object and then set on a target ISA/ABI
|
||
dependant basis. */
|
||
|
||
int
|
||
m68k_get_longjmp_target (CORE_ADDR *pc)
|
||
{
|
||
#if defined (JB_PC) && defined (JB_ELEMENT_SIZE)
|
||
char *buf;
|
||
CORE_ADDR sp, jb_addr;
|
||
|
||
buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
|
||
sp = read_register (SP_REGNUM);
|
||
|
||
if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */
|
||
buf, TARGET_PTR_BIT / TARGET_CHAR_BIT))
|
||
return 0;
|
||
|
||
jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
|
||
|
||
if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
|
||
TARGET_PTR_BIT / TARGET_CHAR_BIT))
|
||
return 0;
|
||
|
||
*pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
|
||
|
||
return 1;
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
"m68k_get_longjmp_target: not implemented");
|
||
return 0;
|
||
#endif
|
||
}
|
||
|
||
/* Immediately after a function call, return the saved pc before the frame
|
||
is setup. For sun3's, we check for the common case of being inside of a
|
||
system call, and if so, we know that Sun pushes the call # on the stack
|
||
prior to doing the trap. */
|
||
|
||
CORE_ADDR
|
||
m68k_saved_pc_after_call (struct frame_info *frame)
|
||
{
|
||
#ifdef SYSCALL_TRAP
|
||
int op;
|
||
|
||
op = read_memory_integer (frame->pc - SYSCALL_TRAP_OFFSET, 2);
|
||
|
||
if (op == SYSCALL_TRAP)
|
||
return read_memory_integer (read_register (SP_REGNUM) + 4, 4);
|
||
else
|
||
#endif /* SYSCALL_TRAP */
|
||
return read_memory_integer (read_register (SP_REGNUM), 4);
|
||
}
|
||
|
||
|
||
void
|
||
_initialize_m68k_tdep (void)
|
||
{
|
||
tm_print_insn = print_insn_m68k;
|
||
}
|