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|
/////////////////////////////////////////////////////////////////////////
// $Id: resolve.cc,v 1.13 2006/08/11 17:22:43 sshwarts Exp $
/////////////////////////////////////////////////////////////////////////
#include <stdio.h>
#include <assert.h>
#include "disasm.h"
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;
insn->nnn |= insn->rex_r;
if (insn->mod == 3) {
/* mod, reg, reg */
insn->rm |= insn->rex_b;
return;
}
if (insn->as_64)
{
if (insn->rm != 4) { /* rm != 100b, no s-i-b byte */
insn->rm |= insn->rex_b;
// one byte modrm
switch (insn->mod) {
case 0:
resolve_modrm = &disassembler::resolve64_mod0;
if ((insn->rm & 7) == 5) /* no reg, 32-bit displacement */
insn->displacement.displ32 = fetch_dword();
break;
case 1:
/* reg, 8-bit displacement, sign extend */
resolve_modrm = &disassembler::resolve64_mod1or2;
insn->displacement.displ32 = (Bit8s) fetch_byte();
break;
case 2:
/* reg, 32-bit displacement */
resolve_modrm = &disassembler::resolve64_mod1or2;
insn->displacement.displ32 = fetch_dword();
break;
} /* switch (mod) */
} /* if (rm != 4) */
else { /* rm == 4, s-i-b byte follows */
insn->sib = fetch_byte();
BX_DECODE_SIB(insn->sib, insn->scale, insn->index, insn->base);
insn->base |= insn->rex_b;
insn->index |= insn->rex_x;
switch (insn->mod) {
case 0:
resolve_modrm = &disassembler::resolve64_mod0_rm4;
if ((insn->base & 7) == 5)
insn->displacement.displ32 = fetch_dword();
break;
case 1:
resolve_modrm = &disassembler::resolve64_mod1or2_rm4;
insn->displacement.displ32 = (Bit8s) fetch_byte();
break;
case 2:
resolve_modrm = &disassembler::resolve64_mod1or2_rm4;
insn->displacement.displ32 = fetch_dword();
break;
}
} /* s-i-b byte follows */
}
else
{
if (insn->as_32)
{
if (insn->rm != 4) { /* rm != 100b, no s-i-b byte */
insn->rm |= insn->rex_b;
// one byte modrm
switch (insn->mod) {
case 0:
resolve_modrm = &disassembler::resolve32_mod0;
if ((insn->rm & 7) == 5) /* no reg, 32-bit displacement */
insn->displacement.displ32 = fetch_dword();
break;
case 1:
/* reg, 8-bit displacement, sign extend */
resolve_modrm = &disassembler::resolve32_mod1or2;
insn->displacement.displ32 = (Bit8s) fetch_byte();
break;
case 2:
/* reg, 32-bit displacement */
resolve_modrm = &disassembler::resolve32_mod1or2;
insn->displacement.displ32 = fetch_dword();
break;
} /* switch (mod) */
} /* if (rm != 4) */
else { /* rm == 4, s-i-b byte follows */
insn->sib = fetch_byte();
BX_DECODE_SIB(insn->sib, insn->scale, insn->index, insn->base);
insn->base |= insn->rex_b;
insn->index |= insn->rex_x;
switch (insn->mod) {
case 0:
resolve_modrm = &disassembler::resolve32_mod0_rm4;
if ((insn->base & 7) == 5)
insn->displacement.displ32 = fetch_dword();
break;
case 1:
resolve_modrm = &disassembler::resolve32_mod1or2_rm4;
insn->displacement.displ32 = (Bit8s) fetch_byte();
break;
case 2:
resolve_modrm = &disassembler::resolve32_mod1or2_rm4;
insn->displacement.displ32 = fetch_dword();
break;
}
} /* s-i-b byte follows */
}
else {
assert(insn->rex_b == 0);
assert(insn->rex_x == 0);
assert(insn->rex_r == 0);
/* 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 = (Bit8s) fetch_byte();
break;
case 2:
resolve_modrm = &disassembler::resolve16_mod1or2;
insn->displacement.displ16 = fetch_word();
break;
} /* switch (mod) ... */
}
}
}
void disassembler::resolve16_mod0(const x86_insn *insn, unsigned mode)
{
const char *seg;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = sreg_mod00_rm16[insn->rm];
if(insn->rm == 6)
print_memory_access16(mode, seg, NULL, insn->displacement.displ16);
else
print_memory_access16(mode, seg, index16[insn->rm], 0);
}
void disassembler::resolve16_mod1or2(const x86_insn *insn, unsigned mode)
{
const char *seg;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = sreg_mod01or10_rm16[insn->rm];
print_memory_access16(mode, seg, index16[insn->rm], insn->displacement.displ16);
}
void disassembler::resolve32_mod0(const x86_insn *insn, unsigned mode)
{
const char *seg;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = segment_name[DS_REG];
if ((insn->rm & 7) == 5) /* no reg, 32-bit displacement */
print_memory_access(mode, seg, NULL, NULL, 0, insn->displacement.displ32);
else
print_memory_access(mode, seg, general_32bit_regname[insn->rm], NULL, 0, 0);
}
void disassembler::resolve32_mod1or2(const x86_insn *insn, unsigned mode)
{
const char *seg;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = sreg_mod01or10_rm32[insn->rm];
print_memory_access(mode, seg,
general_32bit_regname[insn->rm], NULL, 0, insn->displacement.displ32);
}
void disassembler::resolve32_mod0_rm4(const x86_insn *insn, unsigned mode)
{
const char *seg, *base = NULL, *index = NULL;
Bit32u disp32 = 0;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = sreg_mod00_base32[insn->base];
if ((insn->base & 7) != 5)
base = general_32bit_regname[insn->base];
else
disp32 = insn->displacement.displ32;
if (insn->index != 4)
index = general_32bit_regname[insn->index];
print_memory_access(mode, seg, base, index, insn->scale, disp32);
}
void disassembler::resolve32_mod1or2_rm4(const x86_insn *insn, unsigned mode)
{
const char *seg, *index = NULL;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = sreg_mod01or10_base32[insn->base];
if (insn->index != 4)
index = general_32bit_regname[insn->index];
print_memory_access(mode, seg,
general_32bit_regname[insn->base], index, insn->scale, insn->displacement.displ32);
}
void disassembler::resolve64_mod0(const x86_insn *insn, unsigned mode)
{
const char *seg, *rip_regname;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = segment_name[DS_REG];
if (intel_mode) rip_regname = "rip";
else rip_regname = "%rip";
if ((insn->rm & 7) == 5) /* no reg, 32-bit displacement */
print_memory_access(mode, seg, rip_regname, NULL, 0, insn->displacement.displ32);
else
print_memory_access(mode, seg, general_64bit_regname[insn->rm], NULL, 0, 0);
}
void disassembler::resolve64_mod1or2(const x86_insn *insn, unsigned mode)
{
const char *seg;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = sreg_mod01or10_rm32[insn->rm];
print_memory_access(mode, seg,
general_64bit_regname[insn->rm], NULL, 0, insn->displacement.displ32);
}
void disassembler::resolve64_mod0_rm4(const x86_insn *insn, unsigned mode)
{
const char *seg, *base = NULL, *index = NULL;
Bit32u disp32 = 0;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = sreg_mod00_base32[insn->base];
if ((insn->base & 7) != 5)
base = general_64bit_regname[insn->base];
else
disp32 = insn->displacement.displ32;
if (insn->index != 4)
index = general_64bit_regname[insn->index];
print_memory_access(mode, seg, base, index, insn->scale, disp32);
}
void disassembler::resolve64_mod1or2_rm4(const x86_insn *insn, unsigned mode)
{
const char *seg, *index = NULL;
if (insn->is_seg_override())
seg = segment_name[insn->seg_override];
else
seg = sreg_mod01or10_base32[insn->base];
if (insn->index != 4)
index = general_64bit_regname[insn->index];
print_memory_access(mode, seg,
general_64bit_regname[insn->base], index, insn->scale, insn->displacement.displ32);
}
void disassembler::print_datasize(unsigned size)
{
if (!intel_mode) return;
switch(size)
{
case B_SIZE:
dis_sprintf("byte ptr ");
break;
case W_SIZE:
dis_sprintf("word ptr ");
break;
case D_SIZE:
dis_sprintf("dword ptr ");
break;
case Q_SIZE:
dis_sprintf("qword ptr ");
break;
case O_SIZE:
dis_sprintf("dqword ptr ");
break;
case T_SIZE:
dis_sprintf("tbyte ptr ");
break;
case P_SIZE:
break;
case X_SIZE:
break;
};
}
void disassembler::print_memory_access16(int datasize,
const char *seg, const char *index, Bit16u disp)
{
print_datasize(datasize);
if (intel_mode)
{
if (index == NULL)
{
dis_sprintf("%s:0x%x", seg, (unsigned) disp);
}
else
{
if (disp != 0)
dis_sprintf("%s:[%s+0x%x]", seg, index, (unsigned) disp);
else
dis_sprintf("%s:[%s]", seg, index);
}
}
else
{
if (index == NULL)
{
dis_sprintf("%s:0x%x", seg, (unsigned) disp);
}
else
{
if (disp != 0)
dis_sprintf("%s:0x%x(%s,1)", seg, (unsigned) disp, index);
else
dis_sprintf("%s:(%s,1)", seg, index);
}
}
}
void disassembler::print_memory_access(int datasize,
const char *seg, const char *base, const char *index, int scale, Bit32u disp)
{
print_datasize(datasize);
if (intel_mode)
{
if (base == NULL)
{
if (index == NULL)
{
dis_sprintf("%s:0x%x", seg, (unsigned) disp);
}
else
{
if (scale != 0)
{
if (disp != 0)
dis_sprintf("%s:[%s*%d+0x%x]", seg, index, 1<<scale, (unsigned) disp);
else
dis_sprintf("%s:[%s*%d]", seg, index, 1<<scale);
}
else
{
if (disp != 0)
dis_sprintf("%s:[%s+0x%x]", seg, index, (unsigned) disp);
else
dis_sprintf("%s:[%s]", seg, index);
}
}
}
else
{
if (index == NULL)
{
if (disp != 0)
dis_sprintf("%s:[%s+0x%x]", seg, base, (unsigned) disp);
else
dis_sprintf("%s:[%s]", seg, base);
}
else
{
if (scale != 0)
{
if (disp != 0)
dis_sprintf("%s:[%s+%s*%d+0x%x]", seg, base, index, 1<<scale, (unsigned) disp);
else
dis_sprintf("%s:[%s+%s*%d]", seg, base, index, 1<<scale);
}
else
{
if (disp != 0)
dis_sprintf("%s:[%s+%s+0x%x]", seg, base, index, (unsigned) disp);
else
dis_sprintf("%s:[%s+%s]", seg, base, index);
}
}
}
}
else
{
if (base == NULL)
{
if (index == NULL)
{
dis_sprintf("%s:0x%x", seg, (unsigned) disp);
}
else
{
if (disp != 0)
dis_sprintf("%s:0x%x(,%s,%d)", seg, (unsigned) disp, index, 1<<scale);
else
dis_sprintf("%s:(,%s,%d)", seg, index, 1<<scale);
}
}
else
{
if (index == NULL)
{
if (disp != 0)
dis_sprintf("%s:0x%x(%s)", seg, (unsigned) disp, base);
else
dis_sprintf("%s:(%s)", seg, base);
}
else
{
if (disp != 0)
dis_sprintf("%s:0x%x(%s,%s,%d)", seg, (unsigned) disp, base, index, 1<<scale);
else
dis_sprintf("%s:(%s,%s,%d)", seg, base, index, 1<<scale);
}
}
}
}
|
