/* i80960 instruction disassembler for GDB. Copyright 1990, 1991, 1992 Free Software Foundation, Inc. This file is part of GDB. This program 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 2 of the License, or (at your option) any later version. This program 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 this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "defs.h" #include "dis-asm.h" /* Print the 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; { disassemble_info info; GDB_INIT_DISASSEMBLE_INFO(info, stream); return print_insn_i960 (memaddr, &info); } /****************************************/ /* MEM format */ /****************************************/ struct tabent { char *name; char numops; }; static int /* returns instruction length: 4 or 8 */ mem( memaddr, word1, word2, noprint ) unsigned long memaddr; unsigned long word1, word2; int noprint; /* If TRUE, return instruction length, but don't output any text. */ { int i, j; int len; int mode; int offset; const char *reg1, *reg2, *reg3; /* This lookup table is too sparse to make it worth typing in, but not * so large as to make a sparse array necessary. We allocate the * table at runtime, initialize all entries to empty, and copy the * real ones in from an initialization table. * * NOTE: In this table, the meaning of 'numops' is: * 1: single operand * 2: 2 operands, load instruction * -2: 2 operands, store instruction */ static struct tabent *mem_tab = NULL; /* Opcodes of 0x8X, 9X, aX, bX, and cX must be in the table. */ #define MEM_MIN 0x80 #define MEM_MAX 0xcf #define MEM_SIZ ((MEM_MAX-MEM_MIN+1) * sizeof(struct tabent)) static struct { int opcode; char *name; char numops; } mem_init[] = { 0x80, "ldob", 2, 0x82, "stob", -2, 0x84, "bx", 1, 0x85, "balx", 2, 0x86, "callx", 1, 0x88, "ldos", 2, 0x8a, "stos", -2, 0x8c, "lda", 2, 0x90, "ld", 2, 0x92, "st", -2, 0x98, "ldl", 2, 0x9a, "stl", -2, 0xa0, "ldt", 2, 0xa2, "stt", -2, 0xb0, "ldq", 2, 0xb2, "stq", -2, 0xc0, "ldib", 2, 0xc2, "stib", -2, 0xc8, "ldis", 2, 0xca, "stis", -2, 0, NULL, 0 }; if ( mem_tab == NULL ){ mem_tab = (struct tabent *) xmalloc( MEM_SIZ ); bzero( mem_tab, MEM_SIZ ); for ( i = 0; mem_init[i].opcode != 0; i++ ){ j = mem_init[i].opcode - MEM_MIN; mem_tab[j].name = mem_init[i].name; mem_tab[j].numops = mem_init[i].numops; } } i = ((word1 >> 24) & 0xff) - MEM_MIN; mode = (word1 >> 10) & 0xf; if ( (mem_tab[i].name != NULL) /* Valid instruction */ && ((mode == 5) || (mode >=12)) ){ /* With 32-bit displacement */ len = 8; } else { len = 4; } if ( noprint ){ return len; } abort (); } /* Read the i960 instruction at 'memaddr' and return the address of the next instruction after that, or 0 if 'memaddr' is not the address of a valid instruction. The first word of the instruction is stored at 'pword1', and the second word, if any, is stored at 'pword2'. */ CORE_ADDR next_insn (memaddr, pword1, pword2) unsigned long *pword1, *pword2; CORE_ADDR memaddr; { int len; char buf[8]; /* Read the two (potential) words of the instruction at once, to eliminate the overhead of two calls to read_memory (). FIXME: Loses if the first one is readable but the second is not (e.g. last word of the segment). */ read_memory (memaddr, buf, 8); *pword1 = extract_unsigned_integer (buf, 4); *pword2 = extract_unsigned_integer (buf + 4, 4); /* Divide instruction set into classes based on high 4 bits of opcode*/ switch ((*pword1 >> 28) & 0xf) { case 0x0: case 0x1: /* ctrl */ case 0x2: case 0x3: /* cobr */ case 0x5: case 0x6: case 0x7: /* reg */ len = 4; break; case 0x8: case 0x9: case 0xa: case 0xb: case 0xc: len = mem (memaddr, *pword1, *pword2, 1); break; default: /* invalid instruction */ len = 0; break; } if (len) return memaddr + len; else return 0; }