void disassembler::decode_modrm(x86_insn *insn)
{
insn->modrm = fetch_byte();
BX_DECODE_MODRM(insn->modrm, insn->mod, insn->nnn, insn->rm);
// MOVs with CRx and DRx always use register ops and ignore the mod field.
if ((insn->b1 & ~3) == 0x120) insn->mod = 3;
if (insn->mod == 3) {
/* mod, reg, reg */
return;
}
/* 16 bit addressing modes. */
switch (insn->mod) {
case 0:
resolve_modrm = &disassembler::resolve16_mod0;
if(insn->rm == 6)
insn->displacement.displ16 = fetch_word();
break;
case 1:
/* reg, 8-bit displacement, sign extend */
resolve_modrm = &disassembler::resolve16_mod1or2;
insn->displacement.displ16 = (int8) fetch_byte();
break;
case 2:
resolve_modrm = &disassembler::resolve16_mod1or2;
insn->displacement.displ16 = fetch_word();
break;
} /* switch (mod) ... */
}
void _jmpInd(void)
{
word iaddr;
word eaddr;
iaddr = fetch_word((word)(cpu.pc + 1));
eaddr = fetch_word(iaddr);
cpu.pc = eaddr;
}
int do_command(void)
{
const char *cmd;
int i;
char lbuf[10];
cmd = word + 1;
/* Comments don't need the space */
if (strncmp(cmd, "\\\"", 2) == 0)
cmd = "\\\"";
for (i = 0; cmd_list[i].cmd[0]; i++) {
if (strcmp(cmd_list[i].cmd, cmd) == 0)
break;
}
if (cmd_list[i].cmd[0] == 0) {
if (verbose) {
strncpy(lbuf, cmd, 3);
lbuf[3] = 0;
line_break();
i = left_indent;
left_indent = 0;
strcpy(word, "**** Unknown formatter command: .");
strcat(word, lbuf);
print_word(word);
line_break();
left_indent = i;
}
i = 0; /* Treat as comment */
}
switch (cmd_list[i].class) {
case 1: /* Parametered commands */
return do_argvcmd(cmd_list[i].id);
case 2: /* Font changers */
return do_fontwords(cmd_list[i].id / 10,
cmd_list[i].id % 10, 0);
case 3: /* .so */
fetch_word();
strcat(man_file, word);
close_page();
if (find_page(man_file, (char *) 0) < 0) {
fprintf(stderr, "Cannot open .so file %s\n", word);
return -1;
}
ungetc('\r', ifd);
break;
default:
do_skipeol();
if (cmd_list[i].id)
return do_noargs(cmd_list[i].id);
}
return 0;
}
void _styAbsl(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
store_byte(addr, cpu.y);
cpu.pc += 3;
}
void _jsr(void)
{
word addr;
push(hibyte(cpu.pc + 3));
push(lobyte(cpu.pc + 3));
addr = fetch_word((word)(cpu.pc + 1));
cpu.pc = addr;
}
void _staAby(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
addr += cpu.y;
store_byte(addr, cpu.a);
cpu.pc += 3;
}
void _rorAbx(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
ROR((word)(addr + cpu.x));
cpu.pc += 3;
}
void _aslAbsl(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
ASL(addr);
cpu.pc += 3;
}
void _oraAbsl(void)
{
word addr;
word res;
addr = fetch_word((word)(cpu.pc + 1));
res = cpu.a |= fetch_byte(addr);
set_nz(res);
cpu.pc += 3;
}
void _lsrAbx(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
LSR((word)(addr + cpu.x));
cpu.pc += 3;
}
void _lsrAbsl(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
LSR(addr);
cpu.pc += 3;
}
int process_dri(void)
{
if (iceenv.cur_segment_len != 4)
return ERR_INVALID_SEGMENT_SIZE;
iceenv.restart_interval = fetch_word();
iceenv.rstcount = iceenv.restart_interval;
return ERR_OK;
}
void _brk(void)
{
push(hibyte(cpu.pc + sizeof(word)));
push(lobyte(cpu.pc + sizeof(word)));
push(cpu.sr);
set_brk_flag();
set_int_disable_flag();
cpu.pc = fetch_word(IRQ_VECTOR);
}
void _aslAbx(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
ASL((word)(addr + cpu.x));
cpu.pc += 3;
}
void _bitAbsl(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
BIT(addr);
cpu.pc += 3;
}
void _rorAbsl(void)
{
word addr;
addr = fetch_word((word)(cpu.pc + 1));
ROR(addr);
cpu.pc += 3;
}
/*
* add with carry, absolute mode
*/
void _adcAbsl(void)
{
word addr;
byte value;
addr = fetch_word((word)(cpu.pc + 1));
value = fetch_byte(addr);
ADC(value);
cpu.pc += 3;
}
void _ldaAby(void)
{
word addr;
word res;
addr = fetch_word((word)(cpu.pc + 1));
addr += cpu.y;
res = cpu.a = fetch_byte(addr);
set_nz(res);
cpu.pc += 3;
}
void _staIdy(void)
{
byte zaddr;
word addr;
zaddr = fetch_byte((word)(cpu.pc + 1));
addr = fetch_word(zaddr) + cpu.y;
store_byte(addr, cpu.a);
cpu.pc += 2;
}
void _ldyAbx(void)
{
word addr;
word res;
addr = fetch_word((word)(cpu.pc + 1));
addr += cpu.x;
res = cpu.y = fetch_byte(addr);
set_nz(res);
cpu.pc += 3;
}
void _sbcAby(void)
{
word addr;
byte value;
addr = fetch_word((word)(cpu.pc + 1));
value = fetch_byte((word)(addr + cpu.y));
SBC(value);
cpu.pc += 3;
}
void _staIdx(void)
{
byte zaddr;
word addr;
zaddr = fetch_byte((word)(cpu.pc + 1));
zaddr += cpu.x;
addr = fetch_word(zaddr);
store_byte(addr, cpu.a);
cpu.pc += 2;
}
void disassembler::IwIb(const x86_insn *insn)
{
Bit16u iw = fetch_word();
Bit8u ib = fetch_byte();
if (intel_mode) {
dis_sprintf("0x%04x, 0x%02x", iw, ib);
}
else {
dis_sprintf("$0x%02x, $0x%04x", ib, iw);
}
}
/*
* add with carry absolute, y mode
*/
void _adcAby(void)
{
word addr;
byte value;
addr = fetch_word((word)(cpu.pc + 1));
addr += cpu.y;
value = fetch_byte(addr);
ADC(addr);
cpu.pc += 3;
}
void _ldaIdy(void)
{
byte zaddr;
word addr;
word res;
zaddr = fetch_byte((word)(cpu.pc + 1));
addr = fetch_word(zaddr) + cpu.y;
res = cpu.a = fetch_byte(addr);
set_nz(res);
cpu.pc += 2;
}
void _oraIdx(void)
{
byte zaddr;
word addr;
word res;
zaddr = fetch_byte((word)(cpu.pc + 1));
zaddr += cpu.x;
addr = fetch_word(zaddr);
res = cpu.a |= fetch_byte(addr);
set_nz(res);
cpu.pc += 2;
}
/*
* add with carry indirect, y mode
*/
void _adcIdy(void)
{
byte zaddr, value;
word addr;
zaddr = fetch_byte((word)(cpu.pc + 1));
addr = fetch_word(zaddr) + cpu.y;
value = fetch_byte(addr);
ADC(value);
cpu.pc += 2;
}
void _cpyAbsl(void)
{
word addr;
word res;
addr = fetch_word((word)(cpu.pc + 1));
res = cpu.y - fetch_byte(addr);
set_carry(res < 0x100);
set_nz(res);
cpu.pc += 3;
}
void _sbcIdx(void)
{
byte zaddr, value;
word addr;
zaddr = fetch_byte((word)(cpu.pc + 1));
zaddr += cpu.x;
addr = fetch_word(zaddr);
value = fetch_byte(addr);
SBC(value);
cpu.pc += 2;
}
void _decAbsl(void)
{
word addr;
word res;
addr = fetch_word((word)(cpu.pc + 1));
res = fetch_byte(addr);
res = (res - 1) & 0xFF;
store_byte(addr, (byte)res);
set_nz(res);
cpu.pc += 3;
}
