/* Print GOULD RISC instructions for GDB, the GNU debugger. Copyright (C) 1986, 1987, 1989 Free Software Foundation, Inc. This file is part of GDB. GDB is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 1, or (at your option) any later version. GDB is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GDB; see the file COPYING. If not, write to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include "defs.h" #include "param.h" #include "symtab.h" #include "frame.h" #include "opcode.h" /* GOULD RISC instructions are never longer than this many bytes. */ #define MAXLEN 4 /* Number of elements in the opcode table. */ #define NOPCODES (sizeof gld_opcodes / sizeof gld_opcodes[0]) /* Print the GOULD instruction at address MEMADDR in debugged memory, on STREAM. Returns length of the instruction, in bytes. */ int print_insn (memaddr, stream) CORE_ADDR memaddr; FILE *stream; { unsigned char buffer[MAXLEN]; register int i; register char *d; register int bestmask; unsigned best; int temp, index, bestlen; read_memory (memaddr, buffer, MAXLEN); bestmask = 0; index = -1; best = 0xffffffff; for (i = 0; i < NOPCODES; i++) { register unsigned int opcode = gld_opcodes[i].opcode; register unsigned int mask = gld_opcodes[i].mask; register unsigned int len = gld_opcodes[i].length; register unsigned int test; /* Get possible opcode bytes into integer */ test = buffer[0] << 24; test |= buffer[1] << 16; test |= buffer[2] << 8; test |= buffer[3]; /* Mask with opcode and see if match */ if ((opcode & mask) == (test & mask)) { /* See if second or third match */ if (index >= 0) { /* Take new one if it looks good */ if (bestlen == MAXLEN && len == MAXLEN) { /* See if lower bits matched */ if (((bestmask & 3) == 0) && ((mask & 3) != 0)) { bestmask = mask; bestlen = len; best = test; index = i; } } } else { /* First match, save it */ bestmask = mask; bestlen = len; best = test; index = i; } } } /* Handle undefined instructions. */ if (index < 0) { fprintf (stream, "undefined 0%o",(buffer[0]<<8)+buffer[1]); return 2; } /* Print instruction name */ fprintf (stream, "%-12s", gld_opcodes[index].name); /* Adjust if short instruction */ if (gld_opcodes[index].length < 4) { best >>= 16; i = 0; } else { i = 16; } /* Dump out instruction arguments */ for (d = gld_opcodes[index].args; *d; ++d) { switch (*d) { case 'f': fprintf (stream, "%d", (best >> (7 + i)) & 7); break; case 'r': fprintf (stream, "r%d", (best >> (7 + i)) & 7); break; case 'R': fprintf (stream, "r%d", (best >> (4 + i)) & 7); break; case 'b': fprintf (stream, "b%d", (best >> (7 + i)) & 7); break; case 'B': fprintf (stream, "b%d", (best >> (4 + i)) & 7); break; case 'v': fprintf (stream, "b%d", (best >> (7 + i)) & 7); break; case 'V': fprintf (stream, "b%d", (best >> (4 + i)) & 7); break; case 'X': temp = (best >> 20) & 7; if (temp) fprintf (stream, "r%d", temp); else putc ('0', stream); break; case 'A': temp = (best >> 16) & 7; if (temp) fprintf (stream, "(b%d)", temp); break; case 'S': fprintf (stream, "#%d", best & 0x1f); break; case 'I': fprintf (stream, "#%x", best & 0xffff); break; case 'O': fprintf (stream, "%x", best & 0xffff); break; case 'h': fprintf (stream, "%d", best & 0xfffe); break; case 'd': fprintf (stream, "%d", best & 0xfffc); break; case 'T': fprintf (stream, "%d", (best >> 8) & 0xff); break; case 'N': fprintf (stream, "%d", best & 0xff); break; default: putc (*d, stream); break; } } /* Return length of instruction */ return (gld_opcodes[index].length); } /* * Find the number of arguments to a function. */ findarg(frame) struct frame_info *frame; { register struct symbol *func; register unsigned pc; #ifdef notdef /* find starting address of frame function */ pc = get_pc_function_start (frame->pc); /* find function symbol info */ func = find_pc_function (pc); /* call blockframe code to look for match */ if (func != NULL) return (func->value.block->nsyms / sizeof(int)); #endif return (-1); } /* * In the case of the NPL, the frame's norminal address is Br2 and the * previous routines frame is up the stack X bytes. Finding out what * 'X' is can be tricky. * * 1.) stored in the code function header xA(Br1). * 2.) must be careful of recurssion. */ FRAME_ADDR findframe(thisframe) FRAME thisframe; { register FRAME_ADDR pointer; #if 0 struct frame_info *frame; FRAME_ADDR framechain(); /* Setup toplevel frame structure */ frame->pc = read_pc(); frame->next_frame = 0; frame->frame = read_register (SP_REGNUM); /* Br2 */ /* Search for this frame (start at current Br2) */ do { pointer = framechain(frame); frame->next_frame = frame->frame; frame->frame = pointer; frame->pc = FRAME_SAVED_PC(frame); } while (frame->next_frame != thisframe); #endif pointer = framechain (thisframe); /* stop gap for now, end at __base3 */ if (thisframe->pc == 0) return 0; return pointer; } /* * Gdb front-end and internal framechain routine. * Go back up stack one level. Tricky... */ FRAME_ADDR framechain(frame) register struct frame_info *frame; { register CORE_ADDR func, prevsp; register unsigned value; /* Get real function start address from internal frame address */ func = get_pc_function_start(frame->pc); /* If no stack given, read register Br1 "(sp)" */ if (!frame->frame) prevsp = read_register (SP_REGNUM); else prevsp = frame->frame; /* Check function header, case #2 */ value = read_memory_integer (func, 4); if (value) { /* 32bit call push value stored in function header */ prevsp += value; } else { /* read half-word from suabr at start of function */ prevsp += read_memory_integer (func + 10, 2); } return (prevsp); }