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1640 lines (1537 loc) · 45 KB
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#include "x86.h"
#include <cstdint>
#include <stdlib.h>
uint16_t X86_MEM_Read16(uint32_t addr) {
return (X86_MEM_Read8(addr)) | (X86_MEM_Read8(addr + 1) << 8);
}
void X86_MEM_Write16(uint32_t addr, uint16_t val) {
uint8_t p1 = (val >> 0) & 0xFF;
uint8_t p2 = (val >> 8) & 0xFF;
X86_MEM_Write8(addr, p1);
X86_MEM_Write8(addr + 1, p2);
}
uint32_t X86_MEM_Read32(uint32_t addr) {
return (X86_MEM_Read16(addr)) | (X86_MEM_Read16(addr + 2) << 16);
}
void X86_MEM_Write32(uint32_t addr, uint32_t val) {
uint16_t p1 = (val & 0xFFFF0000) >> 16;
uint16_t p2 = (val & 0x0000FFFF);
X86_MEM_Write16(addr, p1);
X86_MEM_Write16(addr + 2, p2);
}
BOOL X86_NOP() { return TRUE; }
BOOL X86_HLT() {
printf("HALT!\n");
printf("(for test186) 00000000h: %04X\n", X86_MEM_Read16(0));
return FALSE;
}
BOOL X86_JMP_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
return TRUE;
}
BOOL X86_JMP_REL16(void) {
uint16_t disp = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp + 1;
return TRUE;
}
BOOL X86_MOV_R16_IMM16(uint16_t *dst, uint16_t imm) {
*dst = imm;
return TRUE;
}
BOOL X86_MOV_R8_IMM8(uint8_t *dst, uint8_t imm) {
*dst = imm;
return TRUE;
}
BOOL X86_MOV_BX_IMM16(void) {
uint16_t imm =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(&X86_CPU_gRegs.EBX.word, imm);
}
BOOL X86_MOV_BP_IMM16(void) {
uint16_t imm =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(&X86_CPU_gRegs.EBP.word, imm);
}
BOOL X86_MOV_SP_IMM16(void) {
uint16_t imm =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(&X86_CPU_gRegs.ESP.word, imm);
}
BOOL X86_MOV_SI_IMM16(void) {
uint16_t imm =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(&X86_CPU_gRegs.ESI.word, imm);
}
BOOL X86_MOV_DI_IMM16(void) {
uint16_t imm =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(&X86_CPU_gRegs.EDI.word, imm);
}
BOOL X86_MOV_AX_IMM16(void) {
uint16_t imm =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(&X86_CPU_gRegs.EAX.word, imm);
}
BOOL X86_MOV_CX_IMM16(void) {
uint16_t imm =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(&X86_CPU_gRegs.ECX.word, imm);
}
BOOL X86_MOV_DX_IMM16(void) {
uint16_t imm =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(&X86_CPU_gRegs.EDX.word, imm);
}
BOOL X86_MOV_AH_IMM8(void) {
return X86_MOV_R8_IMM8(&X86_CPU_gRegs.EAX.h,
X86_MEM_Read8(X86_CPU_SEGOFF(
X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++)));
}
BOOL X86_MOV_AL_IMM8(void) {
return X86_MOV_R8_IMM8(&X86_CPU_gRegs.EAX.l,
X86_MEM_Read8(X86_CPU_SEGOFF(
X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++)));
}
BOOL X86_MOV_BH_IMM8(void) {
return X86_MOV_R8_IMM8(&X86_CPU_gRegs.EBX.h,
X86_MEM_Read8(X86_CPU_SEGOFF(
X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++)));
}
BOOL X86_MOV_BL_IMM8(void) {
return X86_MOV_R8_IMM8(&X86_CPU_gRegs.EBX.l,
X86_MEM_Read8(X86_CPU_SEGOFF(
X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++)));
}
BOOL X86_MOV_CH_IMM8(void) {
return X86_MOV_R8_IMM8(&X86_CPU_gRegs.ECX.h,
X86_MEM_Read8(X86_CPU_SEGOFF(
X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++)));
}
BOOL X86_MOV_CL_IMM8(void) {
return X86_MOV_R8_IMM8(&X86_CPU_gRegs.ECX.l,
X86_MEM_Read8(X86_CPU_SEGOFF(
X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++)));
}
BOOL X86_MOV_DH_IMM8(void) {
return X86_MOV_R8_IMM8(&X86_CPU_gRegs.EDX.h,
X86_MEM_Read8(X86_CPU_SEGOFF(
X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++)));
}
BOOL X86_MOV_DL_IMM8(void) {
return X86_MOV_R8_IMM8(&X86_CPU_gRegs.EDX.l,
X86_MEM_Read8(X86_CPU_SEGOFF(
X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++)));
}
BOOL X86_MOV_R8_RM8(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint8_t *dst;
uint8_t src;
switch (X86_CPU_MODRM_GET_REG1(modrm)) {
case X86_CPU_W0REG_AL:
dst = &X86_CPU_gRegs.EAX.l;
break;
case X86_CPU_W0REG_AH:
dst = &X86_CPU_gRegs.EAX.h;
break;
case X86_CPU_W0REG_CL:
dst = &X86_CPU_gRegs.ECX.l;
break;
case X86_CPU_W0REG_CH:
dst = &X86_CPU_gRegs.ECX.h;
break;
case X86_CPU_W0REG_DL:
dst = &X86_CPU_gRegs.EDX.l;
break;
case X86_CPU_W0REG_DH:
dst = &X86_CPU_gRegs.EDX.h;
break;
case X86_CPU_W0REG_BL:
dst = &X86_CPU_gRegs.EBX.l;
break;
case X86_CPU_W0REG_BH:
dst = &X86_CPU_gRegs.EBX.h;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG1(modrm));
return FALSE;
}
if (X86_CPU_MODRM_GET_MOD(modrm) == 0b11) {
switch (X86_CPU_MODRM_GET_REG2(modrm)) {
case X86_CPU_W0REG_AL:
src = X86_CPU_gRegs.EAX.l;
break;
case X86_CPU_W0REG_AH:
src = X86_CPU_gRegs.EAX.h;
break;
case X86_CPU_W0REG_CL:
src = X86_CPU_gRegs.ECX.l;
break;
case X86_CPU_W0REG_CH:
src = X86_CPU_gRegs.ECX.h;
break;
case X86_CPU_W0REG_DL:
src = X86_CPU_gRegs.EDX.l;
break;
case X86_CPU_W0REG_DH:
src = X86_CPU_gRegs.EDX.h;
break;
case X86_CPU_W0REG_BL:
src = X86_CPU_gRegs.EBX.l;
break;
case X86_CPU_W0REG_BH:
src = X86_CPU_gRegs.EBX.h;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG2(modrm));
return FALSE;
}
return X86_MOV_R8_IMM8(dst, src);
} else {
if (X86_CPU_MODRM_GET_MOD(modrm) == 0 &&
X86_CPU_MODRM_GET_REG2(modrm) == 0b110) {
uint16_t offs = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R8_IMM8(
dst, X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, offs)));
}
}
printf("UNHANDLED MODRM: %02Xh\n", (modrm));
return FALSE;
}
BOOL X86_MOV_R8_RM8_1TO2(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint8_t *dst;
uint8_t src;
switch (X86_CPU_MODRM_GET_REG2(modrm)) {
case X86_CPU_W0REG_AL:
dst = &X86_CPU_gRegs.EAX.l;
break;
case X86_CPU_W0REG_AH:
dst = &X86_CPU_gRegs.EAX.h;
break;
case X86_CPU_W0REG_CL:
dst = &X86_CPU_gRegs.ECX.l;
break;
case X86_CPU_W0REG_CH:
dst = &X86_CPU_gRegs.ECX.h;
break;
case X86_CPU_W0REG_DL:
dst = &X86_CPU_gRegs.EDX.l;
break;
case X86_CPU_W0REG_DH:
dst = &X86_CPU_gRegs.EDX.h;
break;
case X86_CPU_W0REG_BL:
dst = &X86_CPU_gRegs.EBX.l;
break;
case X86_CPU_W0REG_BH:
dst = &X86_CPU_gRegs.EBX.h;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG1(modrm));
return FALSE;
}
if (X86_CPU_MODRM_GET_MOD(modrm) == 0b11) {
switch (X86_CPU_MODRM_GET_REG1(modrm)) {
case X86_CPU_W0REG_AL:
src = X86_CPU_gRegs.EAX.l;
break;
case X86_CPU_W0REG_AH:
src = X86_CPU_gRegs.EAX.h;
break;
case X86_CPU_W0REG_CL:
src = X86_CPU_gRegs.ECX.l;
break;
case X86_CPU_W0REG_CH:
src = X86_CPU_gRegs.ECX.h;
break;
case X86_CPU_W0REG_DL:
src = X86_CPU_gRegs.EDX.l;
break;
case X86_CPU_W0REG_DH:
src = X86_CPU_gRegs.EDX.h;
break;
case X86_CPU_W0REG_BL:
src = X86_CPU_gRegs.EBX.l;
break;
case X86_CPU_W0REG_BH:
src = X86_CPU_gRegs.EBX.h;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG2(modrm));
return FALSE;
}
return X86_MOV_R8_IMM8(dst, src);
} else {
if (X86_CPU_MODRM_GET_MOD(modrm) == 0 &&
X86_CPU_MODRM_GET_REG2(modrm) == 0b110) {
uint16_t offs = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R8_IMM8(
dst, X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, offs)));
}
}
printf("UNHANDLED MODRM: %02Xh\n", (modrm));
return FALSE;
}
BOOL X86_MOV_RM16_R16(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint16_t *dst;
uint16_t src;
switch (X86_CPU_MODRM_GET_REG2(modrm)) {
case X86_CPU_REG_AX:
dst = &X86_CPU_gRegs.EAX.word;
break;
case X86_CPU_REG_CX:
dst = &X86_CPU_gRegs.ECX.word;
break;
case X86_CPU_REG_DX:
dst = &X86_CPU_gRegs.EDX.word;
break;
case X86_CPU_REG_BX:
dst = &X86_CPU_gRegs.EBX.word;
break;
case X86_CPU_REG_SP:
dst = &X86_CPU_gRegs.ESP.word;
break;
case X86_CPU_REG_BP:
dst = &X86_CPU_gRegs.EBP.word;
break;
case X86_CPU_REG_SI:
dst = &X86_CPU_gRegs.ESI.word;
break;
case X86_CPU_REG_DI:
dst = &X86_CPU_gRegs.EDI.word;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG2(modrm));
return FALSE;
}
if (X86_CPU_MODRM_GET_MOD(modrm) == 0b11) {
switch (X86_CPU_MODRM_GET_REG1(modrm)) {
case X86_CPU_REG_AX:
src = X86_CPU_gRegs.EAX.word;
break;
case X86_CPU_REG_CX:
src = X86_CPU_gRegs.ECX.word;
break;
case X86_CPU_REG_DX:
src = X86_CPU_gRegs.EDX.word;
break;
case X86_CPU_REG_BX:
src = X86_CPU_gRegs.EBX.word;
break;
case X86_CPU_REG_SP:
src = X86_CPU_gRegs.ESP.word;
break;
case X86_CPU_REG_BP:
src = X86_CPU_gRegs.EBP.word;
break;
case X86_CPU_REG_SI:
src = X86_CPU_gRegs.ESI.word;
break;
case X86_CPU_REG_DI:
src = X86_CPU_gRegs.EDI.word;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG1(modrm));
return FALSE;
}
return X86_MOV_R16_IMM16(dst, src);
} else {
if (X86_CPU_MODRM_GET_MOD(modrm) == 0) {
if (X86_CPU_MODRM_GET_REG2(modrm) == 0b110) {
src = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(
dst, X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, src)));
} else if (X86_CPU_MODRM_GET_REG2(modrm) == 0b111) {
src = X86_CPU_gRegs.EAX.word;
X86_MEM_Write16(
X86_CPU_SEGOFF(X86_CPU_gRegs.DS, X86_CPU_gRegs.EBX.word), src);
return TRUE;
}
}
}
printf("UNHANDLED MODRM: %02Xh\n", (modrm));
return FALSE;
}
BOOL X86_MOV_R16_RM16(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
switch (modrm) // i can't be arsed to check each bitfield right now
{
case 0x40: {
int8_t disp8 = X86_MEM_Read8(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint16_t offs = X86_CPU_gRegs.EBX.word + X86_CPU_gRegs.ESI.word + disp8;
X86_CPU_gRegs.EAX.word =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, offs));
return TRUE;
}
default:
break;
}
uint16_t *dst;
uint16_t src;
if (X86_CPU_MODRM_GET_MOD(modrm) == 0b11) {
switch (X86_CPU_MODRM_GET_REG1(modrm)) {
case X86_CPU_REG_AX:
dst = &X86_CPU_gRegs.EAX.word;
break;
case X86_CPU_REG_CX:
dst = &X86_CPU_gRegs.ECX.word;
break;
case X86_CPU_REG_DX:
dst = &X86_CPU_gRegs.EDX.word;
break;
case X86_CPU_REG_BX:
dst = &X86_CPU_gRegs.EBX.word;
break;
case X86_CPU_REG_SP:
dst = &X86_CPU_gRegs.ESP.word;
break;
case X86_CPU_REG_BP:
dst = &X86_CPU_gRegs.EBP.word;
break;
case X86_CPU_REG_SI:
dst = &X86_CPU_gRegs.ESI.word;
break;
case X86_CPU_REG_DI:
dst = &X86_CPU_gRegs.EDI.word;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG2(modrm));
return FALSE;
}
switch (X86_CPU_MODRM_GET_REG2(modrm)) {
case X86_CPU_REG_AX:
src = X86_CPU_gRegs.EAX.word;
break;
case X86_CPU_REG_CX:
src = X86_CPU_gRegs.ECX.word;
break;
case X86_CPU_REG_DX:
src = X86_CPU_gRegs.EDX.word;
break;
case X86_CPU_REG_BX:
src = X86_CPU_gRegs.EBX.word;
break;
case X86_CPU_REG_SP:
src = X86_CPU_gRegs.ESP.word;
break;
case X86_CPU_REG_BP:
src = X86_CPU_gRegs.EBP.word;
break;
case X86_CPU_REG_SI:
src = X86_CPU_gRegs.ESI.word;
break;
case X86_CPU_REG_DI:
src = X86_CPU_gRegs.EDI.word;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG1(modrm));
return FALSE;
}
*dst = src;
return TRUE;
}
printf("UNHANDLED MODRM: %02Xh\n", (modrm));
return FALSE;
}
// FIXME
BOOL X86_MOV_SREG_RM16(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint16_t *dst;
uint16_t src;
switch (X86_CPU_MODRM_GET_REG1(modrm)) {
case X86_CPU_SREG_ES:
dst = &X86_CPU_gRegs.ES;
break;
case X86_CPU_SREG_CS:
dst = &X86_CPU_gRegs.CS;
break;
case X86_CPU_SREG_SS:
dst = &X86_CPU_gRegs.SS;
break;
case X86_CPU_SREG_DS:
dst = &X86_CPU_gRegs.DS;
break;
default:
printf("UNHANDLED SREG: %d\n", X86_CPU_MODRM_GET_REG1(modrm));
return FALSE;
}
if (X86_CPU_MODRM_GET_MOD(modrm) == 0b11) {
switch (X86_CPU_MODRM_GET_REG2(modrm)) {
case X86_CPU_REG_AX:
src = X86_CPU_gRegs.EAX.word;
break;
case X86_CPU_REG_CX:
src = X86_CPU_gRegs.ECX.word;
break;
case X86_CPU_REG_DX:
src = X86_CPU_gRegs.EDX.word;
break;
case X86_CPU_REG_BX:
src = X86_CPU_gRegs.EBX.word;
break;
case X86_CPU_REG_SP:
src = X86_CPU_gRegs.ESP.word;
break;
case X86_CPU_REG_BP:
src = X86_CPU_gRegs.EBP.word;
break;
case X86_CPU_REG_SI:
src = X86_CPU_gRegs.ESI.word;
break;
case X86_CPU_REG_DI:
src = X86_CPU_gRegs.EDI.word;
break;
default:
printf("UNHANDLED REG: %d\n", X86_CPU_MODRM_GET_REG2(modrm));
return FALSE;
}
return X86_MOV_R16_IMM16(dst, src);
} else {
if (X86_CPU_MODRM_GET_MOD(modrm) == 0 &&
X86_CPU_MODRM_GET_REG2(modrm) == 0b110) {
src = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(
dst, X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, src)));
}
}
printf("UNHANDLED MODRM: %02Xh\n", (modrm));
return FALSE;
}
BOOL X86_MOV_AX_MOFFS16(void) {
uint16_t offset =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
return X86_MOV_R16_IMM16(
&X86_CPU_gRegs.EAX.word,
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, offset)));
}
BOOL X86_JMP_RM16(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (X86_CPU_MODRM_GET_MOD(modrm) == 0b11 &&
X86_CPU_MODRM_GET_REG1(modrm) == 0b100) {
switch (X86_CPU_MODRM_GET_REG2(modrm)) {
case X86_CPU_REG_AX: { // jmp ax
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EAX.word;
return TRUE;
} break;
case X86_CPU_REG_CX: { // jmp cx
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.ECX.word;
return TRUE;
} break;
case X86_CPU_REG_BX: { // jmp bx
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EBX.word;
return TRUE;
} break;
case X86_CPU_REG_DX: { // jmp cx
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EDX.word;
return TRUE;
} break;
default:
break;
}
}
if (X86_CPU_MODRM_GET_MOD(modrm) == 0b01) {
if (X86_CPU_MODRM_GET_REG2(modrm) == 0b011) {
int8_t disp8 = X86_MEM_Read8(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint16_t offs = X86_CPU_gRegs.EBP.word + X86_CPU_gRegs.EDI.word + disp8;
X86_CPU_gRegs.EIP.word =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.SS, offs));
return TRUE;
} else if (X86_CPU_MODRM_GET_REG2(modrm) == 0b010) {
int8_t disp8 = X86_MEM_Read8(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint16_t offs = X86_CPU_gRegs.EBP.word + X86_CPU_gRegs.ESI.word + disp8;
X86_CPU_gRegs.CS =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.SS, offs) + 2);
X86_CPU_gRegs.EIP.word =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.SS, offs));
return TRUE;
}
}
printf("Unknown modrm for X86_JMP_RM16: %02Xh!\n", modrm);
return FALSE;
}
BOOL X86_LONGJUMP_16(void) {
uint16_t target_ip =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
uint16_t target_cs =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
X86_CPU_gRegs.CS = target_cs;
X86_CPU_gRegs.EIP.word = target_ip;
return TRUE;
}
BOOL X86_MOV_RM8_IMM8(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
switch (modrm) {
case 1: {
X86_MEM_Write8(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, X86_CPU_gRegs.EBX.word +
X86_CPU_gRegs.EDI.word),
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS,
X86_CPU_gRegs.EIP.word++)));
return TRUE;
}
case 0x40: {
int8_t disp8 = X86_MEM_Read8(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint16_t offs = X86_CPU_gRegs.EBX.word + X86_CPU_gRegs.ESI.word + disp8;
uint8_t src = X86_MEM_Read8(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
X86_MEM_Write8(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, offs), src);
return TRUE;
}
default:
break;
}
printf("Unknown modrm for X86_MOV_RM8_IMM8: %02Xh!\n", modrm);
return FALSE;
}
BOOL X86_MOV_RM16_IMM16(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
switch (modrm) {
case 6: {
uint16_t offs = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
uint16_t val = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
X86_MEM_Write16(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, offs), val);
return TRUE;
}
case 0xC0: {
uint16_t val = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
X86_CPU_gRegs.EAX.word = val;
return TRUE;
}
default:
break;
}
printf("Unknown modrm for X86_MOV_RM16_IMM16: %02Xh!\n", modrm);
return FALSE;
}
BOOL X86_MOV_MOFFS16_AX(void) {
uint16_t offs =
X86_MEM_Read16(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
X86_MEM_Write16(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, offs),
X86_CPU_gRegs.EAX.word);
return TRUE;
}
BOOL X86_MOV_RM16_SREG(void) {
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint16_t dst;
uint16_t src;
switch (X86_CPU_MODRM_GET_REG1(modrm)) {
case X86_CPU_SREG_ES:
src = X86_CPU_gRegs.ES;
break;
case X86_CPU_SREG_CS:
src = X86_CPU_gRegs.CS;
break;
case X86_CPU_SREG_SS:
src = X86_CPU_gRegs.SS;
break;
case X86_CPU_SREG_DS:
src = X86_CPU_gRegs.DS;
break;
default:
printf("UNHANDLED SREG: %d\n", X86_CPU_MODRM_GET_REG1(modrm));
return FALSE;
}
if (X86_CPU_MODRM_GET_MOD(modrm) == 0b11) {
switch (X86_CPU_MODRM_GET_REG2(modrm)) {
case X86_CPU_REG_AX:
X86_CPU_gRegs.EAX.word = src;
return TRUE;
case X86_CPU_REG_CX:
X86_CPU_gRegs.ECX.word = src;
return TRUE;
case X86_CPU_REG_DX:
X86_CPU_gRegs.EDX.word = src;
return TRUE;
case X86_CPU_REG_BX:
X86_CPU_gRegs.EBX.word = src;
return TRUE;
case X86_CPU_REG_SP:
X86_CPU_gRegs.ESP.word = src;
return TRUE;
case X86_CPU_REG_BP:
X86_CPU_gRegs.EBP.word = src;
return TRUE;
case X86_CPU_REG_SI:
X86_CPU_gRegs.ESI.word = src;
return TRUE;
case X86_CPU_REG_DI:
X86_CPU_gRegs.EDI.word = src;
return TRUE;
default:
break;
}
} else {
if (X86_CPU_MODRM_GET_MOD(modrm) == 0 &&
X86_CPU_MODRM_GET_REG2(modrm) == 0b110) {
dst = X86_MEM_Read16(
X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word));
X86_CPU_gRegs.EIP.word += 2;
X86_MEM_Write16(X86_CPU_SEGOFF(X86_CPU_gRegs.DS, dst), src);
return TRUE;
}
}
printf("Unknown modrm for X86_MOV_RM16_IMM16: %02Xh!\n", modrm);
return FALSE;
}
BOOL X86_OUT_DX_AX(void) {
uint16_t io_port = X86_CPU_gRegs.EDX.word;
X86_EMU_gActiveMachine->IO_Write16(io_port, X86_CPU_gRegs.EAX.word);
return TRUE;
}
BOOL X86_OUT_IMM8_AL(void) {
uint16_t io_port =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
X86_EMU_gActiveMachine->IO_Write8(io_port, X86_CPU_gRegs.EAX.l);
return TRUE;
}
BOOL X86_IN_AL_IMM8(void) {
uint16_t io_port =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
X86_CPU_gRegs.EAX.l = X86_EMU_gActiveMachine->IO_Read8(io_port);
return TRUE;
}
BOOL X86_CLI(void) {
X86_CPU_CLEARFLAGS(X86_CPU_EFLAGS_IF);
// TODO: VIF for protected mode?
return TRUE;
}
BOOL X86_SAHF(void) {
X86_CPU_gRegs.EFLAGS.l =
X86_CPU_gRegs.EAX
.h; // TODO: copy each used bitflag instead of copying the whole byte
return TRUE;
}
BOOL X86_LAHF(void) {
X86_CPU_gRegs.EAX.h =
X86_CPU_gRegs.EFLAGS
.l; // TODO: copy each used bitflag instead of copying the whole byte
return TRUE;
}
BOOL X86_JNC_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (!X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_CF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JBE_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_CF) ||
X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_ZF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JNZ_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (!X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_ZF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JS_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_SF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JC_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_CF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JNP_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (!X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_PF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JNS_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (!X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_SF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JNO_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (!X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_OF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JP_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_PF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JZ_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_ZF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_JO_REL8(void) {
int8_t disp =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
if (X86_CPU_ISFLAGSET(X86_CPU_EFLAGS_OF)) {
X86_CPU_gRegs.EIP.word = X86_CPU_gRegs.EIP.word + disp;
}
return TRUE;
}
BOOL X86_SHR_8(uint8_t *dst, uint8_t src) {
X86_CPU_gRegs.EFLAGS.dword =
(X86_CPU_gRegs.EFLAGS.dword & ~X86_CPU_EFLAGS_CF) |
(((*dst >> (src - 1)) & 1) << 0);
int result = *dst >> src;
if (src == 1) {
if ((*dst & (1 << 7)) == (result & (1 << 7))) {
X86_CPU_gRegs.EFLAGS.dword &= ~X86_CPU_EFLAGS_OF;
} else {
X86_CPU_gRegs.EFLAGS.dword |= X86_CPU_EFLAGS_OF;
}
}
int parity = 0;
for (int i = 0; i < 8; i++) {
if ((result >> i) & 1) {
parity++;
}
if (parity % 2 == 0) {
X86_CPU_gRegs.EFLAGS.dword |= X86_CPU_EFLAGS_PF;
} else {
X86_CPU_gRegs.EFLAGS.dword &= ~X86_CPU_EFLAGS_PF;
}
if (result & (1 << 7)) {
X86_CPU_gRegs.EFLAGS.dword |= X86_CPU_EFLAGS_SF;
} else {
X86_CPU_gRegs.EFLAGS.dword &= ~X86_CPU_EFLAGS_SF;
}
}
if (result == 0) {
X86_CPU_gRegs.EFLAGS.dword |= X86_CPU_EFLAGS_ZF;
} else {
X86_CPU_gRegs.EFLAGS.dword &= ~X86_CPU_EFLAGS_ZF;
}
*dst = result;
return TRUE;
}
BOOL X86_SHL_8(uint8_t *dst, uint8_t src) {
X86_CPU_gRegs.EFLAGS.dword =
(X86_CPU_gRegs.EFLAGS.dword & ~X86_CPU_EFLAGS_CF) |
(((*dst << (src - 1)) & 1) << 0);
int result = *dst << src;
if (src == 1) {
if ((*dst & (1 << 7)) == (result & (1 << 7))) {
X86_CPU_gRegs.EFLAGS.dword &= ~X86_CPU_EFLAGS_OF;
} else {
X86_CPU_gRegs.EFLAGS.dword |= X86_CPU_EFLAGS_OF;
}
}
int parity = 0;
for (int i = 0; i < 8; i++) {
if ((result >> i) & 1) {
parity++;
}
if (parity % 2 == 0) {
X86_CPU_gRegs.EFLAGS.dword |= X86_CPU_EFLAGS_PF;
} else {
X86_CPU_gRegs.EFLAGS.dword &= ~X86_CPU_EFLAGS_PF;
}
if (result & (1 << 7)) {
X86_CPU_gRegs.EFLAGS.dword |= X86_CPU_EFLAGS_SF;
} else {
X86_CPU_gRegs.EFLAGS.dword &= ~X86_CPU_EFLAGS_SF;
}
}
if (result == 0) {
X86_CPU_gRegs.EFLAGS.dword |= X86_CPU_EFLAGS_ZF;
} else {
X86_CPU_gRegs.EFLAGS.dword &= ~X86_CPU_EFLAGS_ZF;
}
*dst = result;
return TRUE;
}
BOOL X86_D2(void) {
// can be SAL, SHL, or SHR depending on the modrm!
uint8_t modrm =
X86_MEM_Read8(X86_CPU_SEGOFF(X86_CPU_gRegs.CS, X86_CPU_gRegs.EIP.word++));
uint8_t *dst;
uint8_t src;
if ((modrm >> 3) == 0b11101) { // SHR by CL
src = X86_CPU_gRegs.ECX.l;
switch (X86_CPU_MODRM_GET_REG2(modrm)) {
case X86_CPU_W0REG_AL:
dst = &X86_CPU_gRegs.EAX.l;
break;
case X86_CPU_W0REG_AH:
dst = &X86_CPU_gRegs.EAX.h;
break;
case X86_CPU_W0REG_CL:
dst = &X86_CPU_gRegs.ECX.l;
break;
case X86_CPU_W0REG_CH:
dst = &X86_CPU_gRegs.ECX.h;
break;
case X86_CPU_W0REG_DL:
dst = &X86_CPU_gRegs.EDX.l;
break;
case X86_CPU_W0REG_DH:
dst = &X86_CPU_gRegs.EDX.h;
break;
case X86_CPU_W0REG_BL:
dst = &X86_CPU_gRegs.EBX.l;
break;