binutils-gdb/gdb/i960-pinsn.c

183 lines
4.5 KiB
C

/* 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;
}