256 lines
5.8 KiB
C
256 lines
5.8 KiB
C
/* Target-machine dependent code for Hitachi Super-H, for GDB.
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Copyright (C) 1993 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
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/*
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Contributed by Steve Chamberlain
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sac@cygnus.com
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*/
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#include "defs.h"
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#include "frame.h"
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#include "obstack.h"
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#include "symtab.h"
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#include "gdbtypes.h"
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#include "gdbcmd.h"
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#include "value.h"
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#include "dis-asm.h"
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#include "../opcodes/sh-opc.h"
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/* Prologue looks like
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[mov.l <regs>,@-r15]...
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[sts.l pr,@-r15]
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[mov.l r14,@-r15]
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[mov r15,r14]
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*/
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#define IS_STS(x) ((x) == 0x4f22)
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#define IS_PUSH(x) (((x) & 0xff0f) == 0x2f06)
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#define GET_PUSHED_REG(x) (((x) >> 4) & 0xf)
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#define IS_MOV_SP_FP(x) ((x) == 0x6ef3)
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#define IS_ADD_SP(x) (((x) & 0xff00) == 0x7f00)
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/* Skip any prologue before the guts of a function */
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CORE_ADDR
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sh_skip_prologue (start_pc)
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CORE_ADDR start_pc;
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{
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int w;
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w = read_memory_integer (start_pc, 2);
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while (IS_STS (w)
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|| IS_PUSH (w)
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|| IS_MOV_SP_FP (w))
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{
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start_pc += 2;
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w = read_memory_integer (start_pc, 2);
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}
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return start_pc;
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}
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/* Disassemble an instruction */
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int
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print_insn (memaddr, stream)
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CORE_ADDR memaddr;
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FILE *stream;
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{
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disassemble_info info;
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GDB_INIT_DISASSEMBLE_INFO (info, stream);
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return print_insn_sh (memaddr, &info);
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}
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/* Given a GDB frame, determine the address of the calling function's frame.
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This will be used to create a new GDB frame struct, and then
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INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
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For us, the frame address is its stack pointer value, so we look up
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the function prologue to determine the caller's sp value, and return it. */
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FRAME_ADDR
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sh_frame_chain (thisframe)
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FRAME thisframe;
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{
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if (!inside_entry_file (thisframe->pc))
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return (read_memory_integer (FRAME_FP (thisframe), 4));
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else
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return 0;
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}
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/* Put here the code to store, into a struct frame_saved_regs,
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the addresses of the saved registers of frame described by FRAME_INFO.
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This includes special registers such as pc and fp saved in special
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ways in the stack frame. sp is even more special:
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the address we return for it IS the sp for the next frame. */
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void
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frame_find_saved_regs (fi, fsr)
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struct frame_info *fi;
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struct frame_saved_regs *fsr;
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{
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int where[NUM_REGS];
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int rn;
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int have_fp = 0;
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int depth;
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int pc;
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int opc;
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int insn;
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opc = pc = get_pc_function_start (fi->pc);
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insn = read_memory_integer (pc, 2);
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for (rn = 0; rn < NUM_REGS; rn++)
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where[rn] = -1;
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depth = 0;
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/* Loop around examining the prologue insns, but give up
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after 15 of them, since we're getting silly then */
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while (pc < opc + 15 * 2)
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{
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/* See where the registers will be saved to */
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if (IS_PUSH (insn))
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{
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pc += 2;
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rn = GET_PUSHED_REG (insn);
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where[rn] = depth;
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insn = read_memory_integer (pc, 2);
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depth += 4;
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}
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else if (IS_STS (insn))
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{
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pc += 2;
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where[PR_REGNUM] = depth;
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insn = read_memory_integer (pc, 2);
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depth += 4;
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}
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else if (IS_ADD_SP (insn))
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{
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pc += 2;
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depth += -((char) (insn & 0xff));
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insn = read_memory_integer (pc, 2);
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}
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else
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break;
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}
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/* Now we know how deep things are, we can work out their addresses */
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for (rn = 0; rn < NUM_REGS; rn++)
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{
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if (where[rn] >= 0)
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{
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if (rn == FP_REGNUM)
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have_fp = 1;
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fsr->regs[rn] = fi->frame - where[rn] + depth - 4;
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}
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else
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{
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fsr->regs[rn] = 0;
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}
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}
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if (have_fp)
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{
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fsr->regs[SP_REGNUM] = read_memory_integer (fsr->regs[FP_REGNUM], 4);
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}
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else
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{
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fsr->regs[SP_REGNUM] = fi->frame - 4;
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}
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/* Work out the return pc - either from the saved pr or the pr
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value */
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if (fsr->regs[PR_REGNUM])
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{
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fi->return_pc = read_memory_integer (fsr->regs[PR_REGNUM], 4) + 4;
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}
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else
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{
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fi->return_pc = read_register (PR_REGNUM) + 4;
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}
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}
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/* initialize the extra info saved in a FRAME */
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void
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init_extra_frame_info (fromleaf, fi)
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int fromleaf;
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struct frame_info *fi;
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{
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struct frame_saved_regs dummy;
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frame_find_saved_regs (fi, &dummy);
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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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pop_frame ()
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{
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register FRAME 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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struct frame_info *fi;
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fi = get_frame_info (frame);
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fp = fi->frame;
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get_frame_saved_regs (fi, &fsr);
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/* Copy regs from where they were saved in the frame */
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for (regnum = 0; regnum < NUM_REGS; 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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write_register (PC_REGNUM, fi->return_pc);
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write_register (SP_REGNUM, fp + 4);
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flush_cached_frames ();
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set_current_frame (create_new_frame (read_register (FP_REGNUM),
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read_pc ()));
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}
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_initialize_sh_tdep ()
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{
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extern int sim_memory_size;
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/* FIXME, there should be a way to make a CORE_ADDR variable settable. */
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add_show_from_set
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(add_set_cmd ("memory_size", class_support, var_uinteger,
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(char *) &sim_memory_size,
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"Set simulated memory size of simulator target.", &setlist),
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&showlist);
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}
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