295 lines
6.6 KiB
C
295 lines
6.6 KiB
C
/* Print GOULD RISC instructions for GDB, the GNU debugger.
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Copyright (C) 1986, 1987, 1989 Free Software Foundation, Inc.
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This file is part of GDB.
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GDB 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 1, or (at your option)
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any later version.
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GDB 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 GDB; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#ifndef lint
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static char rcsid[] = "$Id: gld-pinsn.c,v 1.2 1993/08/02 17:39:44 mycroft Exp $";
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#endif /* not lint */
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#include <stdio.h>
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#include <a.out.h>
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#include "defs.h"
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#include "param.h"
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#include "symtab.h"
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#include "frame.h"
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#include "opcode.h"
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/* GOULD RISC instructions are never longer than this many bytes. */
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#define MAXLEN 4
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/* Number of elements in the opcode table. */
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#define NOPCODES (sizeof gld_opcodes / sizeof gld_opcodes[0])
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/* Print the GOULD instruction at address MEMADDR in debugged memory,
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on STREAM. Returns length of the instruction, in bytes. */
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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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unsigned char buffer[MAXLEN];
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register int i;
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register char *d;
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register int bestmask;
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unsigned best;
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int temp, index, bestlen;
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read_memory (memaddr, buffer, MAXLEN);
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bestmask = 0;
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index = -1;
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best = 0xffffffff;
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for (i = 0; i < NOPCODES; i++)
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{
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register unsigned int opcode = gld_opcodes[i].opcode;
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register unsigned int mask = gld_opcodes[i].mask;
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register unsigned int len = gld_opcodes[i].length;
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register unsigned int test;
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/* Get possible opcode bytes into integer */
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test = buffer[0] << 24;
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test |= buffer[1] << 16;
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test |= buffer[2] << 8;
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test |= buffer[3];
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/* Mask with opcode and see if match */
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if ((opcode & mask) == (test & mask))
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{
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/* See if second or third match */
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if (index >= 0)
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{
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/* Take new one if it looks good */
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if (bestlen == MAXLEN && len == MAXLEN)
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{
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/* See if lower bits matched */
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if (((bestmask & 3) == 0) &&
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((mask & 3) != 0))
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{
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bestmask = mask;
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bestlen = len;
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best = test;
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index = i;
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}
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}
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}
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else
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{
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/* First match, save it */
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bestmask = mask;
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bestlen = len;
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best = test;
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index = i;
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}
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}
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}
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/* Handle undefined instructions. */
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if (index < 0)
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{
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fprintf (stream, "undefined 0%o",(buffer[0]<<8)+buffer[1]);
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return 2;
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}
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/* Print instruction name */
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fprintf (stream, "%-12s", gld_opcodes[index].name);
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/* Adjust if short instruction */
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if (gld_opcodes[index].length < 4)
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{
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best >>= 16;
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i = 0;
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}
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else
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{
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i = 16;
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}
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/* Dump out instruction arguments */
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for (d = gld_opcodes[index].args; *d; ++d)
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{
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switch (*d)
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{
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case 'f':
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fprintf (stream, "%d", (best >> (7 + i)) & 7);
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break;
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case 'r':
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fprintf (stream, "r%d", (best >> (7 + i)) & 7);
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break;
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case 'R':
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fprintf (stream, "r%d", (best >> (4 + i)) & 7);
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break;
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case 'b':
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fprintf (stream, "b%d", (best >> (7 + i)) & 7);
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break;
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case 'B':
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fprintf (stream, "b%d", (best >> (4 + i)) & 7);
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break;
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case 'v':
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fprintf (stream, "b%d", (best >> (7 + i)) & 7);
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break;
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case 'V':
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fprintf (stream, "b%d", (best >> (4 + i)) & 7);
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break;
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case 'X':
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temp = (best >> 20) & 7;
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if (temp)
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fprintf (stream, "r%d", temp);
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else
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putc ('0', stream);
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break;
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case 'A':
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temp = (best >> 16) & 7;
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if (temp)
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fprintf (stream, "(b%d)", temp);
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break;
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case 'S':
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fprintf (stream, "#%d", best & 0x1f);
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break;
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case 'I':
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fprintf (stream, "#%x", best & 0xffff);
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break;
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case 'O':
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fprintf (stream, "%x", best & 0xffff);
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break;
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case 'h':
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fprintf (stream, "%d", best & 0xfffe);
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break;
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case 'd':
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fprintf (stream, "%d", best & 0xfffc);
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break;
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case 'T':
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fprintf (stream, "%d", (best >> 8) & 0xff);
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break;
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case 'N':
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fprintf (stream, "%d", best & 0xff);
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break;
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default:
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putc (*d, stream);
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break;
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}
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}
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/* Return length of instruction */
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return (gld_opcodes[index].length);
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}
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/*
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* Find the number of arguments to a function.
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*/
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findarg(frame)
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struct frame_info *frame;
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{
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register struct symbol *func;
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register unsigned pc;
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#ifdef notdef
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/* find starting address of frame function */
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pc = get_pc_function_start (frame->pc);
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/* find function symbol info */
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func = find_pc_function (pc);
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/* call blockframe code to look for match */
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if (func != NULL)
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return (func->value.block->nsyms / sizeof(int));
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#endif
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return (-1);
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}
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/*
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* In the case of the NPL, the frame's norminal address is Br2 and the
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* previous routines frame is up the stack X bytes. Finding out what
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* 'X' is can be tricky.
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*
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* 1.) stored in the code function header xA(Br1).
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* 2.) must be careful of recurssion.
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*/
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FRAME_ADDR
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findframe(thisframe)
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FRAME thisframe;
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{
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register FRAME_ADDR pointer;
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#if 0
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struct frame_info *frame;
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FRAME_ADDR framechain();
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/* Setup toplevel frame structure */
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frame->pc = read_pc();
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frame->next_frame = 0;
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frame->frame = read_register (SP_REGNUM); /* Br2 */
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/* Search for this frame (start at current Br2) */
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do
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{
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pointer = framechain(frame);
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frame->next_frame = frame->frame;
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frame->frame = pointer;
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frame->pc = FRAME_SAVED_PC(frame);
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}
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while (frame->next_frame != thisframe);
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#endif
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pointer = framechain (thisframe);
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/* stop gap for now, end at __base3 */
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if (thisframe->pc == 0)
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return 0;
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return pointer;
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}
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/*
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* Gdb front-end and internal framechain routine.
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* Go back up stack one level. Tricky...
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*/
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FRAME_ADDR
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framechain(frame)
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register struct frame_info *frame;
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{
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register CORE_ADDR func, prevsp;
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register unsigned value;
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/* Get real function start address from internal frame address */
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func = get_pc_function_start(frame->pc);
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/* If no stack given, read register Br1 "(sp)" */
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if (!frame->frame)
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prevsp = read_register (SP_REGNUM);
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else
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prevsp = frame->frame;
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/* Check function header, case #2 */
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value = read_memory_integer (func, 4);
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if (value)
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{
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/* 32bit call push value stored in function header */
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prevsp += value;
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}
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else
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{
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/* read half-word from suabr at start of function */
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prevsp += read_memory_integer (func + 10, 2);
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}
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return (prevsp);
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}
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