ref: f5cc6fbe3a7bcf8bdb002c646ddd519014afafd2
dir: /libinterp/das-386.c/
#include <lib9.h>
#include <kernel.h>
int i386inst(ulong, char, char*, int);
int i386das(ulong, char*, int);
int i386instlen(ulong);
static uchar *dasdata;
static char *
_hexify(char *buf, ulong p, int zeros)
{
ulong d;
d = p/16;
if(d)
buf = _hexify(buf, d, zeros-1);
else
while(zeros--)
*buf++ = '0';
*buf++ = "0123456789abcdef"[p&0x0f];
return buf;
}
/*
* an instruction
*/
typedef struct Instr Instr;
struct Instr
{
uchar mem[1+1+1+1+2+1+1+4+4]; /* raw instruction */
ulong addr; /* address of start of instruction */
int n; /* number of bytes in instruction */
char *prefix; /* instr prefix */
char *segment; /* segment override */
uchar jumptype; /* set to the operand type for jump/ret/call */
char osize; /* 'W' or 'L' */
char asize; /* address size 'W' or 'L' */
uchar mod; /* bits 6-7 of mod r/m field */
uchar reg; /* bits 3-5 of mod r/m field */
char ss; /* bits 6-7 of SIB */
char index; /* bits 3-5 of SIB */
char base; /* bits 0-2 of SIB */
short seg; /* segment of far address */
ulong disp; /* displacement */
ulong imm; /* immediate */
ulong imm2; /* second immediate operand */
char *curr; /* fill level in output buffer */
char *end; /* end of output buffer */
char *err; /* error message */
};
/* 386 register (ha!) set */
enum{
AX=0,
CX,
DX,
BX,
SP,
BP,
SI,
DI,
};
/* Operand Format codes */
/*
%A - address size register modifier (!asize -> 'E')
%C - Control register CR0/CR1/CR2
%D - Debug register DR0/DR1/DR2/DR3/DR6/DR7
%I - second immediate operand
%O - Operand size register modifier (!osize -> 'E')
%T - Test register TR6/TR7
%S - size code ('W' or 'L')
%X - Weird opcode: OSIZE == 'W' => "CBW"; else => "CWDE"
%d - displacement 16-32 bits
%e - effective address - Mod R/M value
%f - floating point register F0-F7 - from Mod R/M register
%g - segment register
%i - immediate operand 8-32 bits
%p - PC-relative - signed displacement in immediate field
%r - Reg from Mod R/M
%x - Weird opcode: OSIZE == 'W' => "CWD"; else => "CDQ"
*/
typedef struct Optable Optable;
struct Optable
{
char operand[2];
void *proto; /* actually either (char*) or (Optable*) */
};
/* Operand decoding codes */
enum {
Ib = 1, /* 8-bit immediate - (no sign extension)*/
Ibs, /* 8-bit immediate (sign extended) */
Jbs, /* 8-bit sign-extended immediate in jump or call */
Iw, /* 16-bit immediate -> imm */
Iw2, /* 16-bit immediate -> imm2 */
Iwd, /* Operand-sized immediate (no sign extension)*/
Awd, /* Address offset */
Iwds, /* Operand-sized immediate (sign extended) */
RM, /* Word or long R/M field with register (/r) */
RMB, /* Byte R/M field with register (/r) */
RMOP, /* Word or long R/M field with op code (/digit) */
RMOPB, /* Byte R/M field with op code (/digit) */
RMR, /* R/M register only (mod = 11) */
RMM, /* R/M memory only (mod = 0/1/2) */
R0, /* Base reg of Mod R/M is literal 0x00 */
R1, /* Base reg of Mod R/M is literal 0x01 */
FRMOP, /* Floating point R/M field with opcode */
FRMEX, /* Extended floating point R/M field with opcode */
JUMP, /* Jump or Call flag - no operand */
RET, /* Return flag - no operand */
OA, /* literal 0x0a byte */
PTR, /* Seg:Displacement addr (ptr16:16 or ptr16:32) */
AUX, /* Multi-byte op code - Auxiliary table */
PRE, /* Instr Prefix */
SEG, /* Segment Prefix */
OPOVER, /* Operand size override */
ADDOVER, /* Address size override */
};
static Optable optab0F00[8]=
{
0,0, "MOVW LDT,%e",
0,0, "MOVW TR,%e",
0,0, "MOVW %e,LDT",
0,0, "MOVW %e,TR",
0,0, "VERR %e",
0,0, "VERW %e",
};
static Optable optab0F01[8]=
{
0,0, "MOVL GDTR,%e",
0,0, "MOVL IDTR,%e",
0,0, "MOVL %e,GDTR",
0,0, "MOVL %e,IDTR",
0,0, "MOVW MSW,%e", /* word */
0,0, nil,
0,0, "MOVW %e,MSW", /* word */
};
static Optable optab0FBA[8]=
{
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
Ib,0, "BT%S %i,%e",
Ib,0, "BTS%S %i,%e",
Ib,0, "BTR%S %i,%e",
Ib,0, "BTC%S %i,%e",
};
static Optable optab0F[256]=
{
RMOP,0, optab0F00,
RMOP,0, optab0F01,
RM,0, "LAR %e,%r",
RM,0, "LSL %e,%r",
0,0, nil,
0,0, nil,
0,0, "CLTS",
0,0, nil,
0,0, "INVD",
0,0, "WBINVD",
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
RMR,0, "MOVL %C,%e", /* [0x20] */
RMR,0, "MOVL %D,%e",
RMR,0, "MOVL %e,%C",
RMR,0, "MOVL %e,%D",
RMR,0, "MOVL %T,%e",
0,0, nil,
RMR,0, "MOVL %e,%T",
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, "WRMSR", /* [0x30] */
0,0, "RDTSC",
0,0, "RDMSR",
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
Iwds,0, "JOS %p", /* [0x80] */
Iwds,0, "JOC %p",
Iwds,0, "JCS %p",
Iwds,0, "JCC %p",
Iwds,0, "JEQ %p",
Iwds,0, "JNE %p",
Iwds,0, "JLS %p",
Iwds,0, "JHI %p",
Iwds,0, "JMI %p",
Iwds,0, "JPL %p",
Iwds,0, "JPS %p",
Iwds,0, "JPC %p",
Iwds,0, "JLT %p",
Iwds,0, "JGE %p",
Iwds,0, "JLE %p",
Iwds,0, "JGT %p",
RMB,0, "SETOS %e", /* [0x90] */
RMB,0, "SETOC %e",
RMB,0, "SETCS %e",
RMB,0, "SETCC %e",
RMB,0, "SETEQ %e",
RMB,0, "SETNE %e",
RMB,0, "SETLS %e",
RMB,0, "SETHI %e",
RMB,0, "SETMI %e",
RMB,0, "SETPL %e",
RMB,0, "SETPS %e",
RMB,0, "SETPC %e",
RMB,0, "SETLT %e",
RMB,0, "SETGE %e",
RMB,0, "SETLE %e",
RMB,0, "SETGT %e",
0,0, "PUSHL FS", /* [0xa0] */
0,0, "POPL FS",
0,0, "CPUID",
RM,0, "BT%S %r,%e",
RM,Ib, "SHLD%S %r,%i,%e",
RM,0, "SHLD%S %r,CL,%e",
0,0, nil,
0,0, nil,
0,0, "PUSHL GS",
0,0, "POPL GS",
0,0, nil,
RM,0, "BTS%S %r,%e",
RM,Ib, "SHRD%S %r,%i,%e",
RM,0, "SHRD%S %r,CL,%e",
0,0, nil,
RM,0, "IMUL%S %e,%r",
0,0, nil,
0,0, nil,
RMM,0, "LSS %e,%r", /* [0xb2] */
RM,0, "BTR%S %r,%e",
RMM,0, "LFS %e,%r",
RMM,0, "LGS %e,%r",
RMB,0, "MOVBZX %e,%R",
RM,0, "MOVWZX %e,%R",
0,0, nil,
0,0, nil,
RMOP,0, optab0FBA,
RM,0, "BTC%S %e,%r",
RM,0, "BSF%S %e,%r",
RM,0, "BSR%S %e,%r",
RMB,0, "MOVBSX %e,%R",
RM,0, "MOVWSX %e,%R",
};
static Optable optab80[8]=
{
Ib,0, "ADDB %i,%e",
Ib,0, "ORB %i,%e",
Ib,0, "ADCB %i,%e",
Ib,0, "SBBB %i,%e",
Ib,0, "ANDB %i,%e",
Ib,0, "SUBB %i,%e",
Ib,0, "XORB %i,%e",
Ib,0, "CMPB %e,%i",
};
static Optable optab81[8]=
{
Iwd,0, "ADD%S %i,%e",
Iwd,0, "OR%S %i,%e",
Iwd,0, "ADC%S %i,%e",
Iwd,0, "SBB%S %i,%e",
Iwd,0, "AND%S %i,%e",
Iwd,0, "SUB%S %i,%e",
Iwd,0, "XOR%S %i,%e",
Iwd,0, "CMP%S %e,%i",
};
static Optable optab83[8]=
{
Ibs,0, "ADD%S %i,%e",
Ibs,0, "OR%S %i,%e",
Ibs,0, "ADC%S %i,%e",
Ibs,0, "SBB%S %i,%e",
Ibs,0, "AND%S %i,%e",
Ibs,0, "SUB%S %i,%e",
Ibs,0, "XOR%S %i,%e",
Ibs,0, "CMP%S %e,%i",
};
static Optable optabC0[8] =
{
Ib,0, "ROLB %i,%e",
Ib,0, "RORB %i,%e",
Ib,0, "RCLB %i,%e",
Ib,0, "RCRB %i,%e",
Ib,0, "SHLB %i,%e",
Ib,0, "SHRB %i,%e",
0,0, nil,
Ib,0, "SARB %i,%e",
};
static Optable optabC1[8] =
{
Ib,0, "ROL%S %i,%e",
Ib,0, "ROR%S %i,%e",
Ib,0, "RCL%S %i,%e",
Ib,0, "RCR%S %i,%e",
Ib,0, "SHL%S %i,%e",
Ib,0, "SHR%S %i,%e",
0,0, nil,
Ib,0, "SAR%S %i,%e",
};
static Optable optabD0[8] =
{
0,0, "ROLB %e",
0,0, "RORB %e",
0,0, "RCLB %e",
0,0, "RCRB %e",
0,0, "SHLB %e",
0,0, "SHRB %e",
0,0, nil,
0,0, "SARB %e",
};
static Optable optabD1[8] =
{
0,0, "ROL%S %e",
0,0, "ROR%S %e",
0,0, "RCL%S %e",
0,0, "RCR%S %e",
0,0, "SHL%S %e",
0,0, "SHR%S %e",
0,0, nil,
0,0, "SAR%S %e",
};
static Optable optabD2[8] =
{
0,0, "ROLB CL,%e",
0,0, "RORB CL,%e",
0,0, "RCLB CL,%e",
0,0, "RCRB CL,%e",
0,0, "SHLB CL,%e",
0,0, "SHRB CL,%e",
0,0, nil,
0,0, "SARB CL,%e",
};
static Optable optabD3[8] =
{
0,0, "ROL%S CL,%e",
0,0, "ROR%S CL,%e",
0,0, "RCL%S CL,%e",
0,0, "RCR%S CL,%e",
0,0, "SHL%S CL,%e",
0,0, "SHR%S CL,%e",
0,0, nil,
0,0, "SAR%S CL,%e",
};
static Optable optabD8[8+8] =
{
0,0, "FADDF %e,F0",
0,0, "FMULF %e,F0",
0,0, "FCOMF %e,F0",
0,0, "FCOMFP %e,F0",
0,0, "FSUBF %e,F0",
0,0, "FSUBRF %e,F0",
0,0, "FDIVF %e,F0",
0,0, "FDIVRF %e,F0",
0,0, "FADDD %f,F0",
0,0, "FMULD %f,F0",
0,0, "FCOMD %f,F0",
0,0, "FCOMPD %f,F0",
0,0, "FSUBD %f,F0",
0,0, "FSUBRD %f,F0",
0,0, "FDIVD %f,F0",
0,0, "FDIVRD %f,F0",
};
/*
* optabD9 and optabDB use the following encoding:
* if (0 <= modrm <= 2) instruction = optabDx[modrm&0x07];
* else instruction = optabDx[(modrm&0x3f)+8];
*
* the instructions for MOD == 3, follow the 8 instructions
* for the other MOD values stored at the front of the table.
*/
static Optable optabD9[64+8] =
{
0,0, "FMOVF %e,F0",
0,0, nil,
0,0, "FMOVF F0,%e",
0,0, "FMOVFP F0,%e",
0,0, "FLDENV%S %e",
0,0, "FLDCW %e",
0,0, "FSTENV%S %e",
0,0, "FSTCW %e",
0,0, "FMOVD F0,F0", /* Mod R/M = 11xx xxxx*/
0,0, "FMOVD F1,F0",
0,0, "FMOVD F2,F0",
0,0, "FMOVD F3,F0",
0,0, "FMOVD F4,F0",
0,0, "FMOVD F5,F0",
0,0, "FMOVD F6,F0",
0,0, "FMOVD F7,F0",
0,0, "FXCHD F0,F0",
0,0, "FXCHD F1,F0",
0,0, "FXCHD F2,F0",
0,0, "FXCHD F3,F0",
0,0, "FXCHD F4,F0",
0,0, "FXCHD F5,F0",
0,0, "FXCHD F6,F0",
0,0, "FXCHD F7,F0",
0,0, "FNOP",
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, "FCHS", /* [0x28] */
0,0, "FABS",
0,0, nil,
0,0, nil,
0,0, "FTST",
0,0, "FXAM",
0,0, nil,
0,0, nil,
0,0, "FLD1",
0,0, "FLDL2T",
0,0, "FLDL2E",
0,0, "FLDPI",
0,0, "FLDLG2",
0,0, "FLDLN2",
0,0, "FLDZ",
0,0, nil,
0,0, "F2XM1",
0,0, "FYL2X",
0,0, "FPTAN",
0,0, "FPATAN",
0,0, "FXTRACT",
0,0, "FPREM1",
0,0, "FDECSTP",
0,0, "FNCSTP",
0,0, "FPREM",
0,0, "FYL2XP1",
0,0, "FSQRT",
0,0, "FSINCOS",
0,0, "FRNDINT",
0,0, "FSCALE",
0,0, "FSIN",
0,0, "FCOS",
};
static Optable optabDA[8+8] =
{
0,0, "FADDL %e,F0",
0,0, "FMULL %e,F0",
0,0, "FCOML %e,F0",
0,0, "FCOMLP %e,F0",
0,0, "FSUBL %e,F0",
0,0, "FSUBRL %e,F0",
0,0, "FDIVL %e,F0",
0,0, "FDIVRL %e,F0",
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
R1,0, "FUCOMPP", /* [0x0d] */
};
static Optable optabDB[8+64] =
{
0,0, "FMOVL %e,F0",
0,0, nil,
0,0, "FMOVL F0,%e",
0,0, "FMOVLP F0,%e",
0,0, nil,
0,0, "FMOVX %e,F0",
0,0, nil,
0,0, "FMOVXP F0,%e",
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
0,0, "FCLEX", /* [0x2a] */
0,0, "FINIT",
};
static Optable optabDC[8+8] =
{
0,0, "FADDD %e,F0",
0,0, "FMULD %e,F0",
0,0, "FCOMD %e,F0",
0,0, "FCOMDP %e,F0",
0,0, "FSUBD %e,F0",
0,0, "FSUBRD %e,F0",
0,0, "FDIVD %e,F0",
0,0, "FDIVRD %e,F0",
0,0, "FADDD F0,%f",
0,0, "FMULD F0,%f",
0,0, nil,
0,0, nil,
0,0, "FSUBRD F0,%f",
0,0, "FSUBD F0,%f",
0,0, "FDIVRD F0,%f",
0,0, "FDIVD F0,%f",
};
static Optable optabDD[8+8] =
{
0,0, "FMOVD %e,F0",
0,0, nil,
0,0, "FMOVD F0,%e",
0,0, "FMOVDP F0,%e",
0,0, "FRSTOR%S %e",
0,0, nil,
0,0, "FSAVE%S %e",
0,0, "FSTSW %e",
0,0, "FFREED %f",
0,0, nil,
0,0, "FMOVD %f,F0",
0,0, "FMOVDP %f,F0",
0,0, "FUCOMD %f,F0",
0,0, "FUCOMDP %f,F0",
};
static Optable optabDE[8+8] =
{
0,0, "FADDW %e,F0",
0,0, "FMULW %e,F0",
0,0, "FCOMW %e,F0",
0,0, "FCOMWP %e,F0",
0,0, "FSUBW %e,F0",
0,0, "FSUBRW %e,F0",
0,0, "FDIVW %e,F0",
0,0, "FDIVRW %e,F0",
0,0, "FADDDP F0,%f",
0,0, "FMULDP F0,%f",
0,0, nil,
R1,0, "FCOMPDP",
0,0, "FSUBRDP F0,%f",
0,0, "FSUBDP F0,%f",
0,0, "FDIVRDP F0,%f",
0,0, "FDIVDP F0,%f",
};
static Optable optabDF[8+8] =
{
0,0, "FMOVW %e,F0",
0,0, nil,
0,0, "FMOVW F0,%e",
0,0, "FMOVWP F0,%e",
0,0, "FBLD %e",
0,0, "FMOVL %e,F0",
0,0, "FBSTP %e",
0,0, "FMOVLP F0,%e",
0,0, nil,
0,0, nil,
0,0, nil,
0,0, nil,
R0,0, "FSTSW %OAX",
};
static Optable optabF6[8] =
{
Ib,0, "TESTB %i,%e",
0,0, nil,
0,0, "NOTB %e",
0,0, "NEGB %e",
0,0, "MULB AL,%e",
0,0, "IMULB AL,%e",
0,0, "DIVB AL,%e",
0,0, "IDIVB AL,%e",
};
static Optable optabF7[8] =
{
Iwd,0, "TEST%S %i,%e",
0,0, nil,
0,0, "NOT%S %e",
0,0, "NEG%S %e",
0,0, "MUL%S %OAX,%e",
0,0, "IMUL%S %OAX,%e",
0,0, "DIV%S %OAX,%e",
0,0, "IDIV%S %OAX,%e",
};
static Optable optabFE[8] =
{
0,0, "INCB %e",
0,0, "DECB %e",
};
static Optable optabFF[8] =
{
0,0, "INC%S %e",
0,0, "DEC%S %e",
JUMP,0, "CALL*%S %e",
JUMP,0, "CALLF*%S %e",
JUMP,0, "JMP*%S %e",
JUMP,0, "JMPF*%S %e",
0,0, "PUSHL %e",
};
static Optable optable[256] =
{
RMB,0, "ADDB %r,%e",
RM,0, "ADD%S %r,%e",
RMB,0, "ADDB %e,%r",
RM,0, "ADD%S %e,%r",
Ib,0, "ADDB %i,AL",
Iwd,0, "ADD%S %i,%OAX",
0,0, "PUSHL ES",
0,0, "POPL ES",
RMB,0, "ORB %r,%e",
RM,0, "OR%S %r,%e",
RMB,0, "ORB %e,%r",
RM,0, "OR%S %e,%r",
Ib,0, "ORB %i,AL",
Iwd,0, "OR%S %i,%OAX",
0,0, "PUSHL CS",
AUX,0, optab0F,
RMB,0, "ADCB %r,%e",
RM,0, "ADC%S %r,%e",
RMB,0, "ADCB %e,%r",
RM,0, "ADC%S %e,%r",
Ib,0, "ADCB %i,AL",
Iwd,0, "ADC%S %i,%OAX",
0,0, "PUSHL SS",
0,0, "POPL SS",
RMB,0, "SBBB %r,%e",
RM,0, "SBB%S %r,%e",
RMB,0, "SBBB %e,%r",
RM,0, "SBB%S %e,%r",
Ib,0, "SBBB %i,AL",
Iwd,0, "SBB%S %i,%OAX",
0,0, "PUSHL DS",
0,0, "POPL DS",
RMB,0, "ANDB %r,%e",
RM,0, "AND%S %r,%e",
RMB,0, "ANDB %e,%r",
RM,0, "AND%S %e,%r",
Ib,0, "ANDB %i,AL",
Iwd,0, "AND%S %i,%OAX",
SEG,0, "ES:",
0,0, "DAA",
RMB,0, "SUBB %r,%e",
RM,0, "SUB%S %r,%e",
RMB,0, "SUBB %e,%r",
RM,0, "SUB%S %e,%r",
Ib,0, "SUBB %i,AL",
Iwd,0, "SUB%S %i,%OAX",
SEG,0, "CS:",
0,0, "DAS",
RMB,0, "XORB %r,%e",
RM,0, "XOR%S %r,%e",
RMB,0, "XORB %e,%r",
RM,0, "XOR%S %e,%r",
Ib,0, "XORB %i,AL",
Iwd,0, "XOR%S %i,%OAX",
SEG,0, "SS:",
0,0, "AAA",
RMB,0, "CMPB %r,%e",
RM,0, "CMP%S %r,%e",
RMB,0, "CMPB %e,%r",
RM,0, "CMP%S %e,%r",
Ib,0, "CMPB %i,AL",
Iwd,0, "CMP%S %i,%OAX",
SEG,0, "DS:",
0,0, "AAS",
0,0, "INC%S %OAX",
0,0, "INC%S %OCX",
0,0, "INC%S %ODX",
0,0, "INC%S %OBX",
0,0, "INC%S %OSP",
0,0, "INC%S %OBP",
0,0, "INC%S %OSI",
0,0, "INC%S %ODI",
0,0, "DEC%S %OAX",
0,0, "DEC%S %OCX",
0,0, "DEC%S %ODX",
0,0, "DEC%S %OBX",
0,0, "DEC%S %OSP",
0,0, "DEC%S %OBP",
0,0, "DEC%S %OSI",
0,0, "DEC%S %ODI",
0,0, "PUSH%S %OAX",
0,0, "PUSH%S %OCX",
0,0, "PUSH%S %ODX",
0,0, "PUSH%S %OBX",
0,0, "PUSH%S %OSP",
0,0, "PUSH%S %OBP",
0,0, "PUSH%S %OSI",
0,0, "PUSH%S %ODI",
0,0, "POP%S %OAX",
0,0, "POP%S %OCX",
0,0, "POP%S %ODX",
0,0, "POP%S %OBX",
0,0, "POP%S %OSP",
0,0, "POP%S %OBP",
0,0, "POP%S %OSI",
0,0, "POP%S %ODI",
0,0, "PUSHA%S",
0,0, "POPA%S",
RMM,0, "BOUND %e,%r",
RM,0, "ARPL %r,%e",
SEG,0, "FS:",
SEG,0, "GS:",
OPOVER,0, "",
ADDOVER,0, "",
Iwd,0, "PUSH%S %i",
RM,Iwd, "IMUL%S %e,%i,%r",
Ib,0, "PUSH%S %i",
RM,Ibs, "IMUL%S %e,%i,%r",
0,0, "INSB DX,(%ODI)",
0,0, "INS%S DX,(%ODI)",
0,0, "OUTSB (%ASI),DX",
0,0, "OUTS%S (%ASI),DX",
Jbs,0, "JOS %p",
Jbs,0, "JOC %p",
Jbs,0, "JCS %p",
Jbs,0, "JCC %p",
Jbs,0, "JEQ %p",
Jbs,0, "JNE %p",
Jbs,0, "JLS %p",
Jbs,0, "JHI %p",
Jbs,0, "JMI %p",
Jbs,0, "JPL %p",
Jbs,0, "JPS %p",
Jbs,0, "JPC %p",
Jbs,0, "JLT %p",
Jbs,0, "JGE %p",
Jbs,0, "JLE %p",
Jbs,0, "JGT %p",
RMOPB,0, optab80,
RMOP,0, optab81,
0,0, nil,
RMOP,0, optab83,
RMB,0, "TESTB %r,%e",
RM,0, "TEST%S %r,%e",
RMB,0, "XCHGB %r,%e",
RM,0, "XCHG%S %r,%e",
RMB,0, "MOVB %r,%e",
RM,0, "MOV%S %r,%e",
RMB,0, "MOVB %e,%r",
RM,0, "MOV%S %e,%r",
RM,0, "MOVW %g,%e",
RM,0, "LEA %e,%r",
RM,0, "MOVW %e,%g",
RM,0, "POP%S %e",
0,0, "NOP",
0,0, "XCHG %OCX,%OAX",
0,0, "XCHG %ODX,%OAX",
0,0, "XCHG %OBX,%OAX",
0,0, "XCHG %OSP,%OAX",
0,0, "XCHG %OBP,%OAX",
0,0, "XCHG %OSI,%OAX",
0,0, "XCHG %ODI,%OAX",
0,0, "%X", /* miserable CBW or CWDE */
0,0, "%x", /* idiotic CWD or CDQ */
PTR,0, "CALL%S %d",
0,0, "WAIT",
0,0, "PUSH FLAGS",
0,0, "POP FLAGS",
0,0, "SAHF",
0,0, "LAHF",
Awd,0, "MOVB %i,AL",
Awd,0, "MOV%S %i,%OAX",
Awd,0, "MOVB AL,%i",
Awd,0, "MOV%S %OAX,%i",
0,0, "MOVSB (%ASI),(%ADI)",
0,0, "MOVS%S (%ASI),(%ADI)",
0,0, "CMPSB (%ASI),(%ADI)",
0,0, "CMPS%S (%ASI),(%ADI)",
Ib,0, "TESTB %i,AL",
Iwd,0, "TEST%S %i,%OAX",
0,0, "STOSB AL,(%ADI)",
0,0, "STOS%S %OAX,(%ADI)",
0,0, "LODSB (%ASI),AL",
0,0, "LODS%S (%ASI),%OAX",
0,0, "SCASB (%ADI),AL",
0,0, "SCAS%S (%ADI),%OAX",
Ib,0, "MOVB %i,AL",
Ib,0, "MOVB %i,CL",
Ib,0, "MOVB %i,DL",
Ib,0, "MOVB %i,BL",
Ib,0, "MOVB %i,AH",
Ib,0, "MOVB %i,CH",
Ib,0, "MOVB %i,DH",
Ib,0, "MOVB %i,BH",
Iwd,0, "MOV%S %i,%OAX",
Iwd,0, "MOV%S %i,%OCX",
Iwd,0, "MOV%S %i,%ODX",
Iwd,0, "MOV%S %i,%OBX",
Iwd,0, "MOV%S %i,%OSP",
Iwd,0, "MOV%S %i,%OBP",
Iwd,0, "MOV%S %i,%OSI",
Iwd,0, "MOV%S %i,%ODI",
RMOPB,0, optabC0,
RMOP,0, optabC1,
Iw,0, "RET %i",
RET,0, "RET",
RM,0, "LES %e,%r",
RM,0, "LDS %e,%r",
RMB,Ib, "MOVB %i,%e",
RM,Iwd, "MOV%S %i,%e",
Iw2,Ib, "ENTER %i,%I", /* loony ENTER */
RET,0, "LEAVE", /* bizarre LEAVE */
Iw,0, "RETF %i",
RET,0, "RETF",
0,0, "INT 3",
Ib,0, "INTB %i",
0,0, "INTO",
0,0, "IRET",
RMOPB,0, optabD0,
RMOP,0, optabD1,
RMOPB,0, optabD2,
RMOP,0, optabD3,
OA,0, "AAM",
OA,0, "AAD",
0,0, nil,
0,0, "XLAT",
FRMOP,0, optabD8,
FRMEX,0, optabD9,
FRMOP,0, optabDA,
FRMEX,0, optabDB,
FRMOP,0, optabDC,
FRMOP,0, optabDD,
FRMOP,0, optabDE,
FRMOP,0, optabDF,
Jbs,0, "LOOPNE %p",
Jbs,0, "LOOPE %p",
Jbs,0, "LOOP %p",
Jbs,0, "JCXZ %p",
Ib,0, "INB %i,AL",
Ib,0, "IN%S %i,%OAX",
Ib,0, "OUTB AL,%i",
Ib,0, "OUT%S %OAX,%i",
Iwds,0, "CALL %p",
Iwds,0, "JMP %p",
PTR,0, "JMP %d",
Jbs,0, "JMP %p",
0,0, "INB DX,AL",
0,0, "IN%S DX,%OAX",
0,0, "OUTB AL,DX",
0,0, "OUT%S %OAX,DX",
PRE,0, "LOCK",
0,0, nil,
PRE,0, "REPNE",
PRE,0, "REP",
0,0, "HALT",
0,0, "CMC",
RMOPB,0, optabF6,
RMOP,0, optabF7,
0,0, "CLC",
0,0, "STC",
0,0, "CLI",
0,0, "STI",
0,0, "CLD",
0,0, "STD",
RMOPB,0, optabFE,
RMOP,0, optabFF,
};
/*
* get a byte of the instruction
*/
static int
igetc(Instr *ip, uchar *c)
{
if(ip->n+1 > sizeof(ip->mem)){
kwerrstr("instruction too long");
return -1;
}
*c = dasdata[ip->addr+ip->n];
ip->mem[ip->n++] = *c;
return 1;
}
/*
* get two bytes of the instruction
*/
static int
igets(Instr *ip, ushort *sp)
{
uchar c;
ushort s;
if (igetc(ip, &c) < 0)
return -1;
s = c;
if (igetc(ip, &c) < 0)
return -1;
s |= (c<<8);
*sp = s;
return 1;
}
/*
* get 4 bytes of the instruction
*/
static int
igetl(Instr *ip, ulong *lp)
{
ushort s;
long l;
if (igets(ip, &s) < 0)
return -1;
l = s;
if (igets(ip, &s) < 0)
return -1;
l |= (s<<16);
*lp = l;
return 1;
}
static int
getdisp(Instr *ip, int mod, int rm, int code)
{
uchar c;
ushort s;
if (mod > 2)
return 1;
if (mod == 1) {
if (igetc(ip, &c) < 0)
return -1;
if (c&0x80)
ip->disp = c|0xffffff00;
else
ip->disp = c&0xff;
} else if (mod == 2 || rm == code) {
if (ip->asize == 'E') {
if (igetl(ip, &ip->disp) < 0)
return -1;
} else {
if (igets(ip, &s) < 0)
return -1;
if (s&0x8000)
ip->disp = s|0xffff0000;
else
ip->disp = s;
}
if (mod == 0)
ip->base = -1;
}
return 1;
}
static int
modrm(Instr *ip, uchar c)
{
uchar rm, mod;
mod = (c>>6)&3;
rm = c&7;
ip->mod = mod;
ip->base = rm;
ip->reg = (c>>3)&7;
if (mod == 3) /* register */
return 1;
if (ip->asize == 0) { /* 16-bit mode */
switch(rm)
{
case 0:
ip->base = BX; ip->index = SI;
break;
case 1:
ip->base = BX; ip->index = DI;
break;
case 2:
ip->base = BP; ip->index = SI;
break;
case 3:
ip->base = BP; ip->index = DI;
break;
case 4:
ip->base = SI;
break;
case 5:
ip->base = DI;
break;
case 6:
ip->base = BP;
break;
case 7:
ip->base = BX;
break;
default:
break;
}
return getdisp(ip, mod, rm, 6);
}
if (rm == 4) { /* scummy sib byte */
if (igetc(ip, &c) < 0)
return -1;
ip->ss = (c>>6)&0x03;
ip->index = (c>>3)&0x07;
if (ip->index == 4)
ip->index = -1;
ip->base = c&0x07;
return getdisp(ip, mod, ip->base, 5);
}
return getdisp(ip, mod, rm, 5);
}
static Optable *
mkinstr(Instr *ip, ulong pc)
{
int i, n;
uchar c;
ushort s;
Optable *op, *obase;
char buf[128];
memset(ip, 0, sizeof(*ip));
ip->base = -1;
ip->index = -1;
ip->osize = 'L';
ip->asize = 'E';
ip->addr = pc;
if (igetc(ip, &c) < 0)
return 0;
obase = optable;
newop:
op = &obase[c];
if (op->proto == 0) {
badop:
n = snprint(buf, sizeof(buf), "opcode: ??");
for (i = 0; i < ip->n && n < sizeof(buf)-3; i++, n+=2)
_hexify(buf+n, ip->mem[i], 1);
strcpy(buf+n, "??");
kwerrstr(buf);
return 0;
}
for(i = 0; i < 2 && op->operand[i]; i++) {
switch(op->operand[i])
{
case Ib: /* 8-bit immediate - (no sign extension)*/
if (igetc(ip, &c) < 0)
return 0;
ip->imm = c&0xff;
break;
case Jbs: /* 8-bit jump immediate (sign extended) */
if (igetc(ip, &c) < 0)
return 0;
if (c&0x80)
ip->imm = c|0xffffff00;
else
ip->imm = c&0xff;
ip->jumptype = Jbs;
break;
case Ibs: /* 8-bit immediate (sign extended) */
if (igetc(ip, &c) < 0)
return 0;
if (c&0x80)
if (ip->osize == 'L')
ip->imm = c|0xffffff00;
else
ip->imm = c|0xff00;
else
ip->imm = c&0xff;
break;
case Iw: /* 16-bit immediate -> imm */
if (igets(ip, &s) < 0)
return 0;
ip->imm = s&0xffff;
ip->jumptype = Iw;
break;
case Iw2: /* 16-bit immediate -> in imm2*/
if (igets(ip, &s) < 0)
return 0;
ip->imm2 = s&0xffff;
break;
case Iwd: /* Operand-sized immediate (no sign extension)*/
if (ip->osize == 'L') {
if (igetl(ip, &ip->imm) < 0)
return 0;
} else {
if (igets(ip, &s)< 0)
return 0;
ip->imm = s&0xffff;
}
break;
case Awd: /* Address-sized immediate (no sign extension)*/
if (ip->asize == 'E') {
if (igetl(ip, &ip->imm) < 0)
return 0;
} else {
if (igets(ip, &s)< 0)
return 0;
ip->imm = s&0xffff;
}
break;
case Iwds: /* Operand-sized immediate (sign extended) */
if (ip->osize == 'L') {
if (igetl(ip, &ip->imm) < 0)
return 0;
} else {
if (igets(ip, &s)< 0)
return 0;
if (s&0x8000)
ip->imm = s|0xffff0000;
else
ip->imm = s&0xffff;
}
ip->jumptype = Iwds;
break;
case OA: /* literal 0x0a byte */
if (igetc(ip, &c) < 0)
return 0;
if (c != 0x0a)
goto badop;
break;
case R0: /* base register must be R0 */
if (ip->base != 0)
goto badop;
break;
case R1: /* base register must be R1 */
if (ip->base != 1)
goto badop;
break;
case RMB: /* R/M field with byte register (/r)*/
if (igetc(ip, &c) < 0)
return 0;
if (modrm(ip, c) < 0)
return 0;
ip->osize = 'B';
break;
case RM: /* R/M field with register (/r) */
if (igetc(ip, &c) < 0)
return 0;
if (modrm(ip, c) < 0)
return 0;
break;
case RMOPB: /* R/M field with op code (/digit) */
if (igetc(ip, &c) < 0)
return 0;
if (modrm(ip, c) < 0)
return 0;
c = ip->reg; /* secondary op code */
obase = (Optable*)op->proto;
ip->osize = 'B';
goto newop;
case RMOP: /* R/M field with op code (/digit) */
if (igetc(ip, &c) < 0)
return 0;
if (modrm(ip, c) < 0)
return 0;
c = ip->reg;
obase = (Optable*)op->proto;
goto newop;
case FRMOP: /* FP R/M field with op code (/digit) */
if (igetc(ip, &c) < 0)
return 0;
if (modrm(ip, c) < 0)
return 0;
if ((c&0xc0) == 0xc0)
c = ip->reg+8; /* 16 entry table */
else
c = ip->reg;
obase = (Optable*)op->proto;
goto newop;
case FRMEX: /* Extended FP R/M field with op code (/digit) */
if (igetc(ip, &c) < 0)
return 0;
if (modrm(ip, c) < 0)
return 0;
if ((c&0xc0) == 0xc0)
c = (c&0x3f)+8; /* 64-entry table */
else
c = ip->reg;
obase = (Optable*)op->proto;
goto newop;
case RMR: /* R/M register only (mod = 11) */
if (igetc(ip, &c) < 0)
return 0;
if ((c&0xc0) != 0xc0) {
kwerrstr("invalid R/M register: %x", c);
return 0;
}
if (modrm(ip, c) < 0)
return 0;
break;
case RMM: /* R/M register only (mod = 11) */
if (igetc(ip, &c) < 0)
return 0;
if ((c&0xc0) == 0xc0) {
kwerrstr("invalid R/M memory mode: %x", c);
return 0;
}
if (modrm(ip, c) < 0)
return 0;
break;
case PTR: /* Seg:Displacement addr (ptr16:16 or ptr16:32) */
if (ip->osize == 'L') {
if (igetl(ip, &ip->disp) < 0)
return 0;
} else {
if (igets(ip, &s)< 0)
return 0;
ip->disp = s&0xffff;
}
if (igets(ip, (ushort*)&ip->seg) < 0)
return 0;
ip->jumptype = PTR;
break;
case AUX: /* Multi-byte op code - Auxiliary table */
obase = (Optable*)op->proto;
if (igetc(ip, &c) < 0)
return 0;
goto newop;
case PRE: /* Instr Prefix */
ip->prefix = (char*)op->proto;
if (igetc(ip, &c) < 0)
return 0;
goto newop;
case SEG: /* Segment Prefix */
ip->segment = (char*)op->proto;
if (igetc(ip, &c) < 0)
return 0;
goto newop;
case OPOVER: /* Operand size override */
ip->osize = 'W';
if (igetc(ip, &c) < 0)
return 0;
goto newop;
case ADDOVER: /* Address size override */
ip->asize = 0;
if (igetc(ip, &c) < 0)
return 0;
goto newop;
case JUMP: /* mark instruction as JUMP or RET */
case RET:
ip->jumptype = op->operand[i];
break;
default:
kwerrstr("bad operand type %d", op->operand[i]);
return 0;
}
}
return op;
}
static void
bprint(Instr *ip, char *fmt, ...)
{
va_list arg;
va_start(arg, fmt);
ip->curr = vseprint(ip->curr, ip->end, fmt, arg);
va_end(arg);
}
/*
* if we want to call 16 bit regs AX,BX,CX,...
* and 32 bit regs EAX,EBX,ECX,... then
* change the defs of ANAME and ONAME to:
* #define ANAME(ip) ((ip->asize == 'E' ? "E" : "")
* #define ONAME(ip) ((ip)->osize == 'L' ? "E" : "")
*/
#define ANAME(ip) ""
#define ONAME(ip) ""
static char *reg[] = {
"AX",
"CX",
"DX",
"BX",
"SP",
"BP",
"SI",
"DI",
};
static char *breg[] = { "AL", "CL", "DL", "BL", "AH", "CH", "DH", "BH" };
static char *sreg[] = { "ES", "CS", "SS", "DS", "FS", "GS" };
static void
plocal(Instr *ip)
{
int offset;
offset = ip->disp;
bprint(ip, "%lux(SP)", offset);
}
static void
pea(Instr *ip)
{
if (ip->mod == 3) {
if (ip->osize == 'B')
bprint(ip, breg[ip->base]);
else
bprint(ip, "%s%s", ANAME(ip), reg[ip->base]);
return;
}
if (ip->segment)
bprint(ip, ip->segment);
if (ip->asize == 'E' && ip->base == SP)
plocal(ip);
else {
bprint(ip,"%lux", ip->disp);
if (ip->base >= 0)
bprint(ip,"(%s%s)", ANAME(ip), reg[ip->base]);
}
if (ip->index >= 0)
bprint(ip,"(%s%s*%d)", ANAME(ip), reg[ip->index], 1<<ip->ss);
}
static void
immediate(Instr *ip, long val)
{
bprint(ip, "%lux", val);
}
static void
prinstr(Instr *ip, char *fmt)
{
if (ip->prefix)
bprint(ip, "%s ", ip->prefix);
for (; *fmt && ip->curr < ip->end; fmt++) {
if (*fmt != '%')
*ip->curr++ = *fmt;
else switch(*++fmt)
{
case '%':
*ip->curr++ = '%';
break;
case 'A':
bprint(ip, "%s", ANAME(ip));
break;
case 'C':
bprint(ip, "CR%d", ip->reg);
break;
case 'D':
if (ip->reg < 4 || ip->reg == 6 || ip->reg == 7)
bprint(ip, "DR%d",ip->reg);
else
bprint(ip, "???");
break;
case 'I':
bprint(ip, "$");
immediate(ip, ip->imm2);
break;
case 'O':
bprint(ip,"%s", ONAME(ip));
break;
case 'i':
bprint(ip, "$");
immediate(ip,ip->imm);
break;
case 'R':
bprint(ip, "%s%s", ONAME(ip), reg[ip->reg]);
break;
case 'S':
bprint(ip, "%c", ip->osize);
break;
case 'T':
if (ip->reg == 6 || ip->reg == 7)
bprint(ip, "TR%d",ip->reg);
else
bprint(ip, "???");
break;
case 'X':
if (ip->osize == 'L')
bprint(ip,"CWDE");
else
bprint(ip, "CBW");
break;
case 'd':
bprint(ip,"%lux:%lux",ip->seg,ip->disp);
break;
case 'e':
pea(ip);
break;
case 'f':
bprint(ip, "F%d", ip->base);
break;
case 'g':
if (ip->reg < 6)
bprint(ip,"%s",sreg[ip->reg]);
else
bprint(ip,"???");
break;
case 'p':
immediate(ip, ip->imm+ip->addr+ip->n);
break;
case 'r':
if (ip->osize == 'B')
bprint(ip,"%s",breg[ip->reg]);
else
bprint(ip, reg[ip->reg]);
break;
case 'x':
if (ip->osize == 'L')
bprint(ip,"CDQ");
else
bprint(ip, "CWD");
break;
default:
bprint(ip, "%%%c", *fmt);
break;
}
}
*ip->curr = 0; /* there's always room for 1 byte */
}
int
i386inst(ulong pc, char modifier, char *buf, int n)
{
Instr instr;
Optable *op;
USED(modifier);
op = mkinstr(&instr, pc);
if (op == 0) {
kgerrstr(buf, n);
return -1;
}
instr.curr = buf;
instr.end = buf+n-1;
prinstr(&instr, op->proto);
return instr.n;
}
int
i386das(ulong pc, char *buf, int n)
{
Instr instr;
int i;
if (mkinstr(&instr, pc) == 0) {
kgerrstr(buf, n);
return -1;
}
for(i = 0; i < instr.n && n > 2; i++) {
_hexify(buf, instr.mem[i], 1);
buf += 2;
n -= 2;
}
*buf = 0;
return instr.n;
}
int
i386instlen(ulong pc)
{
Instr i;
if (mkinstr(&i, pc))
return i.n;
return -1;
}
void
das(uchar *x, int n)
{
int l, pc;
char buf[128];
/*
int i;
for(i = 0; i < n; i++)
print("%.2ux", x[i]);
print("\n");
*/
dasdata = x;
pc = 0;
while(n > 0) {
i386das(pc, buf, sizeof(buf));
print("%.8lux %2x %-20s ", (ulong)(dasdata+pc), pc, buf);
l = i386inst(pc, 'i', buf, sizeof(buf));
print("\t%s\n", buf);
pc += l;
n -= l;
}
}