Add 6502 analysis module

Include all documented 6502 opcodes
Esil expression is still work in progress
Fix BRK opcode->size in 6502_disas
This commit is contained in:
Ricardo Quesada 2015-09-17 10:34:23 -07:00 committed by pancake
parent 7f0a116830
commit 557d45bca1
3 changed files with 688 additions and 143 deletions

View File

@ -108,6 +108,9 @@ ANAL_OBJS += p/anal_dalvik.c ;
# GB
ANAL_OBJS += p/anal_gb.c ;
# 6502
ANAL_OBJS += p/anal_6502.c ;
lib r_anal : $(ANAL_OBJS) :
<include>../include
<define>CORELIB

View File

@ -1,5 +1,6 @@
/* radare - LGPL - Copyright 2015 - condret */
/* radare - LGPL - Copyright 2015 - condret, riq */
/* 6502 info taken from http://unusedino.de/ec64/technical/aay/c64/bchrt651.htm */
#include <string.h>
#include <r_types.h>
@ -8,127 +9,659 @@
#include <r_anal.h>
#include "../../asm/arch/snes/snes_op_table.h"
static void _6502_anal_esil_call(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "2,sp,-=,pc,sp,=[2],0x%04x,pc,=", (op->jump & 0xffff));
}
static void _6502_anal_esil_ccall(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "0x%04x,pc,=", (op->jump & 0xffff));
}
static void _6502_anal_esil_ret(RAnalOp *op)
{
r_strbuf_append (&op->esil, "sp,[2],pc,=,2,sp,+=");
}
static void _6502_anal_esil_jmp(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "0x%04x,pc,=", (op->jump & 0xffff));
}
static void _6502_anal_esil_store(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_load(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_mov(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_push(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_pop(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_or(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_and(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_xor(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_shift(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_rol(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_cmp(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_flags(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_add(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static void _6502_anal_esil_sub(RAnalOp *op)
{
r_strbuf_setf (&op->esil, "TODO");
}
static int _6502_op(RAnal *anal, RAnalOp *op, ut64 addr, const ut8 *data, int len) {
memset (op, '\0', sizeof (RAnalOp));
op->size = snes_op[data[0]].len; //snes-arch is similiar to nes/6502
op->addr = addr;
op->type = R_ANAL_OP_TYPE_UNK;
r_strbuf_init (&op->esil);
switch (data[0]) {
case 0x80:
case 0x02:
case 0x03:
case 0x04:
case 0x07:
case 0x0b:
case 0x0c:
case 0x0f:
case 0x12:
case 0x13:
case 0x14:
case 0x22:
case 0x23:
case 0x32:
case 0x33:
case 0x34:
case 0x42:
case 0x43:
case 0x44:
case 0x52:
case 0x53:
case 0x54:
case 0x62:
case 0x63:
case 0x64:
case 0x72:
case 0x73:
case 0x74:
case 0x82:
case 0x83:
case 0x92:
case 0x93:
case 0xa3:
case 0xb2:
case 0xb3:
case 0xc2:
case 0xc3:
case 0xd2:
case 0xd3:
case 0xd4:
case 0xe2:
case 0xe3:
case 0xf2:
case 0xf3:
case 0xf4:
case 0x07:
case 0x17:
case 0x27:
case 0x37:
case 0x47:
case 0x57:
case 0x67:
case 0x77:
case 0x87:
case 0x97:
case 0xa7:
case 0xb7:
case 0xc7:
case 0xd7:
case 0xe7:
case 0xf7:
case 0x89:
case 0x0b:
case 0x0c:
case 0x1a:
case 0x1b:
case 0x1c:
case 0x1f:
case 0x22:
case 0x23:
case 0x27:
case 0x2b:
case 0x2f:
case 0x32:
case 0x33:
case 0x34:
case 0x37:
case 0x3a:
case 0x3b:
case 0x3c:
case 0x3f:
case 0x42:
case 0x43:
case 0x44:
case 0x47:
case 0x4b:
case 0x4f:
case 0x52:
case 0x53:
case 0x54:
case 0x57:
case 0x5a:
case 0x5b:
case 0x5c:
case 0x5f:
case 0x62:
case 0x63:
case 0x64:
case 0x67:
case 0x6b:
case 0x6f:
case 0x72:
case 0x73:
case 0x74:
case 0x77:
case 0x7a:
case 0x7b:
case 0x7c:
case 0x7f:
case 0x80:
case 0x82:
case 0x83:
case 0x87:
case 0x89:
case 0x8b:
case 0x8f:
case 0x92:
case 0x93:
case 0x97:
case 0x9b:
case 0x9c:
case 0x9e:
case 0x9f:
case 0xa3:
case 0xa7:
case 0xab:
case 0xaf:
case 0xb2:
case 0xb3:
case 0xb7:
case 0xbb:
case 0xbf:
case 0xc2:
case 0xc3:
case 0xc7:
case 0xcb:
case 0xcf:
case 0xd2:
case 0xd3:
case 0xd4:
case 0xd7:
case 0xda:
case 0xdb:
case 0xdc:
case 0xdf:
case 0xe2:
case 0xe3:
case 0xe7:
case 0xeb:
case 0xef:
case 0xf2:
case 0xf3:
case 0xf4:
case 0xf7:
case 0xfa:
case 0xfb:
case 0xfc:
case 0x0f:
case 0x1f:
case 0x2f:
case 0x3f:
case 0x4f:
case 0x5f:
case 0x6f:
case 0x7f:
case 0x8f:
case 0x9e:
case 0x9f:
case 0xaf:
case 0xbf:
case 0xcf:
case 0xdf:
case 0xef:
case 0xff:
// undocumented or not-implemented opcodes for 6502.
// some of them might be implemented in 65816
op->size = 1;
op->type = R_ANAL_OP_TYPE_ILL; //those do not exist for 6502 - snes only
op->type = R_ANAL_OP_TYPE_ILL;
break;
case 0xea:
// BRK
case 0x00: // brk
// takes one byte, but pc+2 instead of pc+1
// overrides SNES size
op->size = 1;
op->cycles = 7;
// FIXME: Not sure if there is an opcode for this one
op->type = R_ANAL_OP_TYPE_UNK;
break;
// FLAGS
case 0x78: // sei
case 0x58: // cli
case 0x38: // sec
case 0x18: // clc
case 0xf8: // sed
case 0xd8: // cld
case 0xb8: // clv
op->cycles = 2;
// FIXME: what opcode for this?
op->type = R_ANAL_OP_TYPE_NOP;
_6502_anal_esil_flags (op);
break;
// ORA
case 0x09: // ora #$ff
case 0x05: // ora $ff
case 0x15: // ora $ff,x
case 0x0d: // ora $ffff
case 0x1d: // ora $ffff,x
case 0x19: // ora $ffff,y
case 0x01: // ora ($ff,x)
case 0x11: // ora ($ff),y
// FIXME: set correct cycles for each opcode
op->cycles = 5;
op->type = R_ANAL_OP_TYPE_OR;
_6502_anal_esil_or (op);
break;
// AND
case 0x29: // and #$ff
case 0x25: // and $ff
case 0x35: // and $ff,x
case 0x2d: // and $ffff
case 0x3d: // and $ffff,x
case 0x39: // and $ffff,y
case 0x21: // and ($ff,x)
case 0x31: // and ($ff),y
// FIXME: set correct cycles for each opcode
op->cycles = 5;
op->type = R_ANAL_OP_TYPE_AND;
_6502_anal_esil_and (op);
break;
// EOR
case 0x49: // eor #$ff
case 0x45: // eor $ff
case 0x55: // eor $ff,x
case 0x4d: // eor $ffff
case 0x5d: // eor $ffff,x
case 0x59: // eor $ffff,y
case 0x41: // eor ($ff,x)
case 0x51: // eor ($ff),y
// FIXME: set correct cycles for each opcode
op->cycles = 5;
op->type = R_ANAL_OP_TYPE_XOR;
_6502_anal_esil_xor (op);
break;
// ASL
case 0x0a: // asl a
case 0x06: // asl $ff
case 0x16: // asl $ff,x
case 0x0e: // asl $ffff
case 0x1e: // asl $ffff,x
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_SHL;
_6502_anal_esil_shift (op);
break;
// LSR
case 0x4a: // lsr a
case 0x46: // lsr $ff
case 0x56: // lsr $ff,x
case 0x4e: // lsr $ffff
case 0x5e: // lsr $ffff,x
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_SHR;
_6502_anal_esil_shift (op);
break;
// ROL
case 0x2a: // rol a
case 0x26: // rol $ff
case 0x36: // rol $ff,x
case 0x2e: // rol $ffff
case 0x3e: // rol $ffff,x
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_ROL;
_6502_anal_esil_rol (op);
break;
// ROR
case 0x6a: // ror a
case 0x66: // ror $ff
case 0x76: // ror $ff,x
case 0x6e: // ror $ffff
case 0x7e: // ror $ffff,x
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_ROR;
_6502_anal_esil_rol (op);
break;
// INC
case 0xe6: // inc $ff
case 0xf6: // inc $ff,x
case 0xee: // inc $ffff
case 0xfe: // inc $ffff,x
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_STORE;
_6502_anal_esil_store (op);
break;
// DEC
case 0xc6: // dec $ff
case 0xd6: // dec $ff,x
case 0xce: // dec $ffff
case 0xde: // dec $ffff,x
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_STORE;
_6502_anal_esil_store (op);
break;
// INY,INX,DEY,DEX
case 0xe8: // inx
case 0xca: // dex
case 0xc8: // iny
case 0x88: // dey
op->cycles = 2;
op->type = R_ANAL_OP_TYPE_STORE;
_6502_anal_esil_load (op);
break;
// CMP
case 0xc9: // cmp #$ff
case 0xc5: // cmp $ff
case 0xd5: // cmp $ff,x
case 0xcd: // cmp $ffff
case 0xdd: // cmp $ffff,x
case 0xd9: // cmp $ffff,y
case 0xc1: // cmp ($ff,x)
case 0xd1: // cmp ($ff),y
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_CMP;
_6502_anal_esil_cmp (op);
break;
// CPX
case 0xe0: // cpx #$ff
case 0xe4: // cpx $ff
case 0xec: // cpx $ffff
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_CMP;
_6502_anal_esil_cmp (op);
break;
// CPY
case 0xc0: // cpy #$ff
case 0xc4: // cpy $ff
case 0xcc: // cpy $ffff
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_CMP;
_6502_anal_esil_cmp (op);
break;
// ADC
case 0x69: // adc #$ff
case 0x65: // adc $ff
case 0x75: // adc $ff,x
case 0x6d: // adc $ffff
case 0x7d: // adc $ffff,x
case 0x79: // adc $ffff,y
case 0x61: // adc ($ff,x)
case 0x71: // adc ($ff,y)
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_ADD;
_6502_anal_esil_add (op);
break;
// SBC
case 0xe9: // sbc #$ff
case 0xe5: // sbc $ff
case 0xf5: // sbc $ff,x
case 0xed: // sbc $ffff
case 0xfd: // sbc $ffff,x
case 0xf9: // sbc $ffff,y
case 0xe1: // sbc ($ff,x)
case 0xf1: // sbc ($ff,y)
// FIXME: set correct cycles for each opcode
op->cycles = 7;
op->type = R_ANAL_OP_TYPE_SUB;
_6502_anal_esil_sub (op);
break;
// BRANCHES
case 0x10: // bpl $ffff
case 0x30: // bmi $ffff
case 0x50: // bvc $ffff
case 0x70: // bvs $ffff
case 0x90: // bcc $ffff
case 0xb0: // bcs $ffff
case 0xd0: // bne $ffff
case 0xf0: // beq $ffff
// FIXME: it could be one more if page crossing. How can I find this out?
op->cycles = 2;
op->failcycles = 3;
op->type = R_ANAL_OP_TYPE_CJMP;
if (data[1] <= 127)
op->jump = addr + data[1] + op->size;
else
op->jump = addr - (256-data[1]) + op->size;
op->fail = addr + op->size;
// FIXME: add a type of conditional
// op->cond = R_ANAL_COND_LE;
_6502_anal_esil_ccall (op);
break;
// JSR
case 0x20: // jsr $ffff
op->cycles = 6;
op->type = R_ANAL_OP_TYPE_CALL;
op->jump = data[1] | data[2] << 8;
op->stackop = R_ANAL_STACK_INC;
op->stackptr = 2;
_6502_anal_esil_call (op);
break;
// JMP
case 0x4c: // jmp $ffff
op->cycles = 3;
op->type = R_ANAL_OP_TYPE_JMP;
op->jump = data[1] | data[2] << 8;
_6502_anal_esil_jmp (op);
break;
case 0x6c: // jmp ($ffff)
op->cycles = 5;
op->type = R_ANAL_OP_TYPE_UJMP;
// op->jump = data[1] | data[2] << 8;
_6502_anal_esil_jmp (op);
break;
// RTS
case 0x60: // rts
op->eob = 1;
op->type = R_ANAL_OP_TYPE_RET;
op->cycles = 6;
op->stackop = R_ANAL_STACK_INC;
op->stackptr = -2;
_6502_anal_esil_ret (op);
break;
// RTI
case 0x40: // rti
op->eob = 1;
op->type = R_ANAL_OP_TYPE_RET;
op->cycles = 6;
op->stackop = R_ANAL_STACK_INC;
op->stackptr = -3; // pops PC and P
_6502_anal_esil_ret (op);
break;
// NOP
case 0xea: // nop
op->type = R_ANAL_OP_TYPE_NOP;
op->cycles = 2;
break;
// LDA
case 0xa9: // lda #$ff
case 0xa5: // lda $ff
case 0xb5: // lda $ff,x
case 0xad: // lda $ffff
case 0xbd: // lda $ffff,x
case 0xb9: // lda $ffff,y
case 0xa1: // lda ($ff,x)
case 0xb1: // lda ($ff),y
op->type = R_ANAL_OP_TYPE_LOAD;
op->cycles = 6; // FIXME
_6502_anal_esil_load (op);
break;
// LDX
case 0xa2: // ldx #$ff
case 0xa6: // ldx $ff
case 0xb6: // ldx $ff,y
case 0xae: // ldx $ffff
case 0xbe: // ldx $ffff,y
op->type = R_ANAL_OP_TYPE_LOAD;
op->cycles = 6; // FIXME
_6502_anal_esil_load (op);
break;
// LDY
case 0xa0: // ldy #$ff
case 0xa4: // ldy $ff
case 0xb4: // ldy $ff,x
case 0xac: // ldy $ffff
case 0xbc: // ldy $ffff,x
op->type = R_ANAL_OP_TYPE_LOAD;
op->cycles = 6; // FIXME
_6502_anal_esil_load (op);
break;
// STA
case 0x85: // sta $ff
case 0x95: // sta $ff,x
case 0x8d: // sta $ffff
case 0x9d: // sta $ffff,x
case 0x99: // sta $ffff,y
case 0x81: // sta ($ff,x)
case 0x91: // sta ($ff),y
op->type = R_ANAL_OP_TYPE_STORE;
op->cycles = 6; // FIXME
_6502_anal_esil_store (op);
break;
// STX
case 0x86: // stx $ff
case 0x96: // stx $ff,y
case 0x8e: // stx $ffff
op->type = R_ANAL_OP_TYPE_STORE;
op->cycles = 6; // FIXME
_6502_anal_esil_store (op);
break;
// STY
case 0x84: // sty $ff
case 0x94: // sty $ff,x
case 0x8c: // sty $ffff
op->type = R_ANAL_OP_TYPE_STORE;
op->cycles = 6; // FIXME
_6502_anal_esil_store (op);
break;
// PHP/PHA
case 0x08: // php
case 0x48: // pha
op->type = R_ANAL_OP_TYPE_PUSH;
op->cycles = 3;
op->stackop = R_ANAL_STACK_INC;
op->stackptr = 1;
_6502_anal_esil_push (op);
break;
// PLP,PLA
case 0x28: // plp
case 0x68: // plp
op->type = R_ANAL_OP_TYPE_POP;
op->cycles = 4;
op->stackop = R_ANAL_STACK_INC;
op->stackptr = -1;
_6502_anal_esil_pop (op);
break;
// TAX,TYA,...
case 0xaa: // tax
case 0x8a: // txa
case 0xa8: // tay
case 0x98: // tya
op->type = R_ANAL_OP_TYPE_MOV;
op->cycles = 2;
_6502_anal_esil_mov (op);
break;
case 0x9a: // txs
op->type = R_ANAL_OP_TYPE_MOV;
op->cycles = 2;
op->stackop = R_ANAL_STACK_SET;
// FIXME: get register X a place it here
// op->stackptr = get_register_x();
_6502_anal_esil_mov (op);
break;
case 0xba: // tsx
op->type = R_ANAL_OP_TYPE_MOV;
op->cycles = 2;
op->stackop = R_ANAL_STACK_GET;
_6502_anal_esil_mov (op);
break;
}
return op->size;
}
static int set_reg_profile(RAnal *anal) {
char *p =
"=pc pc\n"
"=sp sp\n"
"gpr a .8 0 0\n"
"gpr x .8 1 0\n"
"gpr y .8 2 0\n"
"gpr flags .8 3 0\n"
"flg C .1 .24 0\n"
"flg Z .1 .25 0\n"
"flg I .1 .26 0\n"
"flg D .1 .27 0\n"
"flg B .1 .28 0\n"
// bit 5 (.29) is not used
"flg V .1 .30 0\n"
"flg N .1 .31 0\n"
"gpr sp .8 4 0\n"
"gpr pc .16 5 0\n";
return r_reg_set_profile_string (anal->reg, p);
}
static int esil_gb_init (RAnalEsil *esil) {
if (esil->anal && esil->anal->reg) { //initial values
r_reg_set_value (esil->anal->reg, r_reg_get (esil->anal->reg, "pc", -1), 0xc000);
r_reg_set_value (esil->anal->reg, r_reg_get (esil->anal->reg, "sp", -1), 0x00);
r_reg_set_value (esil->anal->reg, r_reg_get (esil->anal->reg, "a", -1), 0x00);
r_reg_set_value (esil->anal->reg, r_reg_get (esil->anal->reg, "x", -1), 0x00);
r_reg_set_value (esil->anal->reg, r_reg_get (esil->anal->reg, "y", -1), 0x00);
}
return true;
}
static int esil_gb_fini (RAnalEsil *esil) {
return true;
}
struct r_anal_plugin_t r_anal_plugin_6502 = {
.name = "6502",
.desc = "6502/NES analysis plugin",
@ -138,12 +671,14 @@ struct r_anal_plugin_t r_anal_plugin_6502 = {
.init = NULL,
.fini = NULL,
.op = &_6502_op,
.set_reg_profile = NULL,
.fingerprint_bb = NULL,
.fingerprint_fcn = NULL,
.diff_bb = NULL,
.diff_fcn = NULL,
.diff_eval = NULL
.diff_eval = NULL,
.set_reg_profile = &set_reg_profile,
.esil_init = esil_gb_init,
.esil_fini = esil_gb_fini,
};
#ifndef CORELIB

View File

@ -5,111 +5,118 @@
static int _6502Disass (RAsmOp *op, const ut8 *buf, ut64 len)
{
// override snes (65816) values
switch (*buf) {
case 0x80:
case 0x00:
// takes one byte, but pc+2 instead of pc+1
// should we report it as one byte or two?
// defaulting to one, since most Commodore disassemblers/monitors do that
sprintf(op->buf_asm,"%s","brk");
return 1;
case 0x02:
case 0x03:
case 0x04:
case 0x07:
case 0x0b:
case 0x0c:
case 0x0f:
case 0x12:
case 0x13:
case 0x14:
case 0x22:
case 0x23:
case 0x32:
case 0x33:
case 0x34:
case 0x42:
case 0x43:
case 0x44:
case 0x52:
case 0x53:
case 0x54:
case 0x62:
case 0x63:
case 0x64:
case 0x72:
case 0x73:
case 0x74:
case 0x82:
case 0x83:
case 0x92:
case 0x93:
case 0xa3:
case 0xb2:
case 0xb3:
case 0xc2:
case 0xc3:
case 0xd2:
case 0xd3:
case 0xd4:
case 0xe2:
case 0xe3:
case 0xf2:
case 0xf3:
case 0xf4:
case 0x07:
case 0x17:
case 0x27:
case 0x37:
case 0x47:
case 0x57:
case 0x67:
case 0x77:
case 0x87:
case 0x97:
case 0xa7:
case 0xb7:
case 0xc7:
case 0xd7:
case 0xe7:
case 0xf7:
case 0x89:
case 0x0b:
case 0x0c:
case 0x1a:
case 0x1b:
case 0x1c:
case 0x1f:
case 0x22:
case 0x23:
case 0x27:
case 0x2b:
case 0x2f:
case 0x32:
case 0x33:
case 0x34:
case 0x37:
case 0x3a:
case 0x3b:
case 0x3c:
case 0x3f:
case 0x42:
case 0x43:
case 0x44:
case 0x47:
case 0x4b:
case 0x4f:
case 0x52:
case 0x53:
case 0x54:
case 0x57:
case 0x5a:
case 0x5b:
case 0x5c:
case 0x5f:
case 0x62:
case 0x63:
case 0x64:
case 0x67:
case 0x6b:
case 0x6f:
case 0x72:
case 0x73:
case 0x74:
case 0x77:
case 0x7a:
case 0x7b:
case 0x7c:
case 0x7f:
case 0x80:
case 0x82:
case 0x83:
case 0x87:
case 0x89:
case 0x8b:
case 0x8f:
case 0x92:
case 0x93:
case 0x97:
case 0x9b:
case 0x9c:
case 0x9e:
case 0x9f:
case 0xa3:
case 0xa7:
case 0xab:
case 0xaf:
case 0xb2:
case 0xb3:
case 0xb7:
case 0xbb:
case 0xbf:
case 0xc2:
case 0xc3:
case 0xc7:
case 0xcb:
case 0xcf:
case 0xd2:
case 0xd3:
case 0xd4:
case 0xd7:
case 0xda:
case 0xdb:
case 0xdc:
case 0xdf:
case 0xe2:
case 0xe3:
case 0xe7:
case 0xeb:
case 0xef:
case 0xf2:
case 0xf3:
case 0xf4:
case 0xf7:
case 0xfa:
case 0xfb:
case 0xfc:
case 0x0f:
case 0x1f:
case 0x2f:
case 0x3f:
case 0x4f:
case 0x5f:
case 0x6f:
case 0x7f:
case 0x8f:
case 0x9e:
case 0x9f:
case 0xaf:
case 0xbf:
case 0xcf:
case 0xdf:
case 0xef:
case 0xff:
strcpy (op->buf_asm, "illegal");
return 1;