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/*
* Hacker Disassembler Engine 32 C
* Copyright (c) 2008-2009, Vyacheslav Patkov.
* All rights reserved.
*
*/
#include <intrin.h>
#include "hde32.h"
#include "table32.h"
unsigned int hde32_disasm(const void *code, hde32s *hs)
{
uint8_t x, c, *p = (uint8_t *)code, cflags, opcode, pref = 0;
uint8_t *ht = hde32_table, m_mod, m_reg, m_rm, disp_size = 0;
// Avoid using memset to reduce the footprint.
__stosb((LPBYTE)hs, 0, sizeof(hde32s));
for (x = 16; x; x--)
switch (c = *p++) {
case 0xf3:
hs->p_rep = c;
pref |= PRE_F3;
break;
case 0xf2:
hs->p_rep = c;
pref |= PRE_F2;
break;
case 0xf0:
hs->p_lock = c;
pref |= PRE_LOCK;
break;
case 0x26: case 0x2e: case 0x36:
case 0x3e: case 0x64: case 0x65:
hs->p_seg = c;
pref |= PRE_SEG;
break;
case 0x66:
hs->p_66 = c;
pref |= PRE_66;
break;
case 0x67:
hs->p_67 = c;
pref |= PRE_67;
break;
default:
goto pref_done;
}
pref_done:
hs->flags = (uint32_t)pref << 23;
if (!pref)
pref |= PRE_NONE;
if ((hs->opcode = c) == 0x0f) {
hs->opcode2 = c = *p++;
ht += DELTA_OPCODES;
} else if (c >= 0xa0 && c <= 0xa3) {
if (pref & PRE_67)
pref |= PRE_66;
else
pref &= ~PRE_66;
}
opcode = c;
cflags = ht[ht[opcode / 4] + (opcode % 4)];
if (cflags == C_ERROR) {
hs->flags |= F_ERROR | F_ERROR_OPCODE;
cflags = 0;
if ((opcode & -3) == 0x24)
cflags++;
}
x = 0;
if (cflags & C_GROUP) {
uint16_t t;
t = *(uint16_t *)(ht + (cflags & 0x7f));
cflags = (uint8_t)t;
x = (uint8_t)(t >> 8);
}
if (hs->opcode2) {
ht = hde32_table + DELTA_PREFIXES;
if (ht[ht[opcode / 4] + (opcode % 4)] & pref)
hs->flags |= F_ERROR | F_ERROR_OPCODE;
}
if (cflags & C_MODRM) {
hs->flags |= F_MODRM;
hs->modrm = c = *p++;
hs->modrm_mod = m_mod = c >> 6;
hs->modrm_rm = m_rm = c & 7;
hs->modrm_reg = m_reg = (c & 0x3f) >> 3;
if (x && ((x << m_reg) & 0x80))
hs->flags |= F_ERROR | F_ERROR_OPCODE;
if (!hs->opcode2 && opcode >= 0xd9 && opcode <= 0xdf) {
uint8_t t = opcode - 0xd9;
if (m_mod == 3) {
ht = hde32_table + DELTA_FPU_MODRM + t*8;
t = ht[m_reg] << m_rm;
} else {
ht = hde32_table + DELTA_FPU_REG;
t = ht[t] << m_reg;
}
if (t & 0x80)
hs->flags |= F_ERROR | F_ERROR_OPCODE;
}
if (pref & PRE_LOCK) {
if (m_mod == 3) {
hs->flags |= F_ERROR | F_ERROR_LOCK;
} else {
uint8_t *table_end, op = opcode;
if (hs->opcode2) {
ht = hde32_table + DELTA_OP2_LOCK_OK;
table_end = ht + DELTA_OP_ONLY_MEM - DELTA_OP2_LOCK_OK;
} else {
ht = hde32_table + DELTA_OP_LOCK_OK;
table_end = ht + DELTA_OP2_LOCK_OK - DELTA_OP_LOCK_OK;
op &= -2;
}
for (; ht != table_end; ht++)
if (*ht++ == op) {
if (!((*ht << m_reg) & 0x80))
goto no_lock_error;
else
break;
}
hs->flags |= F_ERROR | F_ERROR_LOCK;
no_lock_error:
;
}
}
if (hs->opcode2) {
switch (opcode) {
case 0x20: case 0x22:
m_mod = 3;
if (m_reg > 4 || m_reg == 1)
goto error_operand;
else
goto no_error_operand;
case 0x21: case 0x23:
m_mod = 3;
if (m_reg == 4 || m_reg == 5)
goto error_operand;
else
goto no_error_operand;
}
} else {
switch (opcode) {
case 0x8c:
if (m_reg > 5)
goto error_operand;
else
goto no_error_operand;
case 0x8e:
if (m_reg == 1 || m_reg > 5)
goto error_operand;
else
goto no_error_operand;
}
}
if (m_mod == 3) {
uint8_t *table_end;
if (hs->opcode2) {
ht = hde32_table + DELTA_OP2_ONLY_MEM;
table_end = ht + sizeof(hde32_table) - DELTA_OP2_ONLY_MEM;
} else {
ht = hde32_table + DELTA_OP_ONLY_MEM;
table_end = ht + DELTA_OP2_ONLY_MEM - DELTA_OP_ONLY_MEM;
}
for (; ht != table_end; ht += 2)
if (*ht++ == opcode) {
if (*ht++ & pref && !((*ht << m_reg) & 0x80))
goto error_operand;
else
break;
}
goto no_error_operand;
} else if (hs->opcode2) {
switch (opcode) {
case 0x50: case 0xd7: case 0xf7:
if (pref & (PRE_NONE | PRE_66))
goto error_operand;
break;
case 0xd6:
if (pref & (PRE_F2 | PRE_F3))
goto error_operand;
break;
case 0xc5:
goto error_operand;
}
goto no_error_operand;
} else
goto no_error_operand;
error_operand:
hs->flags |= F_ERROR | F_ERROR_OPERAND;
no_error_operand:
c = *p++;
if (m_reg <= 1) {
if (opcode == 0xf6)
cflags |= C_IMM8;
else if (opcode == 0xf7)
cflags |= C_IMM_P66;
}
switch (m_mod) {
case 0:
if (pref & PRE_67) {
if (m_rm == 6)
disp_size = 2;
} else
if (m_rm == 5)
disp_size = 4;
break;
case 1:
disp_size = 1;
break;
case 2:
disp_size = 2;
if (!(pref & PRE_67))
disp_size <<= 1;
}
if (m_mod != 3 && m_rm == 4 && !(pref & PRE_67)) {
hs->flags |= F_SIB;
p++;
hs->sib = c;
hs->sib_scale = c >> 6;
hs->sib_index = (c & 0x3f) >> 3;
if ((hs->sib_base = c & 7) == 5 && !(m_mod & 1))
disp_size = 4;
}
p--;
switch (disp_size) {
case 1:
hs->flags |= F_DISP8;
hs->disp.disp8 = *p;
break;
case 2:
hs->flags |= F_DISP16;
hs->disp.disp16 = *(uint16_t *)p;
break;
case 4:
hs->flags |= F_DISP32;
hs->disp.disp32 = *(uint32_t *)p;
}
p += disp_size;
} else if (pref & PRE_LOCK)
hs->flags |= F_ERROR | F_ERROR_LOCK;
if (cflags & C_IMM_P66) {
if (cflags & C_REL32) {
if (pref & PRE_66) {
hs->flags |= F_IMM16 | F_RELATIVE;
hs->imm.imm16 = *(uint16_t *)p;
p += 2;
goto disasm_done;
}
goto rel32_ok;
}
if (pref & PRE_66) {
hs->flags |= F_IMM16;
hs->imm.imm16 = *(uint16_t *)p;
p += 2;
} else {
hs->flags |= F_IMM32;
hs->imm.imm32 = *(uint32_t *)p;
p += 4;
}
}
if (cflags & C_IMM16) {
if (hs->flags & F_IMM32) {
hs->flags |= F_IMM16;
hs->disp.disp16 = *(uint16_t *)p;
} else if (hs->flags & F_IMM16) {
hs->flags |= F_2IMM16;
hs->disp.disp16 = *(uint16_t *)p;
} else {
hs->flags |= F_IMM16;
hs->imm.imm16 = *(uint16_t *)p;
}
p += 2;
}
if (cflags & C_IMM8) {
hs->flags |= F_IMM8;
hs->imm.imm8 = *p++;
}
if (cflags & C_REL32) {
rel32_ok:
hs->flags |= F_IMM32 | F_RELATIVE;
hs->imm.imm32 = *(uint32_t *)p;
p += 4;
} else if (cflags & C_REL8) {
hs->flags |= F_IMM8 | F_RELATIVE;
hs->imm.imm8 = *p++;
}
disasm_done:
if ((hs->len = (uint8_t)(p-(uint8_t *)code)) > 15) {
hs->flags |= F_ERROR | F_ERROR_LENGTH;
hs->len = 15;
}
return (unsigned int)hs->len;
}
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In 1985, I got my first computer Casio MX-10, the cheapest one of
MSX home computers. Then I began programming in BASIC and assembly language, and have experienced over ten languages from that time on.
Now, my primary languages are C++ and C#. Working for a small company in my home town in a rural area of Japan.
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