ops.c

u-boot 源代码

}

/****************************************************************************
REMARKS:
Handles opcode 0x8a
****************************************************************************/
void x86emuOp_mov_byte_R_RM(u8 X86EMU_UNUSED(op1))
{
    int mod, rl, rh;
    u8 *destreg, *srcreg;
    uint srcoffset;
    u8 srcval;

    START_OF_INSTR();
    DECODE_PRINTF("MOV\t");
    FETCH_DECODE_MODRM(mod, rh, rl);
    if (mod < 3) {
	destreg = DECODE_RM_BYTE_REGISTER(rh);
	DECODE_PRINTF(",");
	srcoffset = decode_rmXX_address(mod, rl);
	srcval = fetch_data_byte(srcoffset);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	*destreg = srcval;
    } else {			 /* register to register */
	destreg = DECODE_RM_BYTE_REGISTER(rh);
	DECODE_PRINTF(",");
	srcreg = DECODE_RM_BYTE_REGISTER(rl);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	*destreg = *srcreg;
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x8b
****************************************************************************/
void x86emuOp_mov_word_R_RM(u8 X86EMU_UNUSED(op1))
{
    int mod, rl, rh;
    uint srcoffset;

    START_OF_INSTR();
    DECODE_PRINTF("MOV\t");
    FETCH_DECODE_MODRM(mod, rh, rl);
    if (mod < 3) {
	if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	    u32 *destreg;
	    u32 srcval;

	    destreg = DECODE_RM_LONG_REGISTER(rh);
	    DECODE_PRINTF(",");
	    srcoffset = decode_rmXX_address(mod, rl);
	    srcval = fetch_data_long(srcoffset);
	    DECODE_PRINTF("\n");
	    TRACE_AND_STEP();
	    *destreg = srcval;
	} else {
	    u16 *destreg;
	    u16 srcval;

	    destreg = DECODE_RM_WORD_REGISTER(rh);
	    DECODE_PRINTF(",");
	    srcoffset = decode_rmXX_address(mod, rl);
	    srcval = fetch_data_word(srcoffset);
	    DECODE_PRINTF("\n");
	    TRACE_AND_STEP();
	    *destreg = srcval;
	}
    } else {			 /* register to register */
	if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	    u32 *destreg, *srcreg;

	    destreg = DECODE_RM_LONG_REGISTER(rh);
	    DECODE_PRINTF(",");
	    srcreg = DECODE_RM_LONG_REGISTER(rl);
	    DECODE_PRINTF("\n");
	    TRACE_AND_STEP();
	    *destreg = *srcreg;
	} else {
	    u16 *destreg, *srcreg;

	    destreg = DECODE_RM_WORD_REGISTER(rh);
	    DECODE_PRINTF(",");
	    srcreg = DECODE_RM_WORD_REGISTER(rl);
	    DECODE_PRINTF("\n");
	    TRACE_AND_STEP();
	    *destreg = *srcreg;
	}
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x8c
****************************************************************************/
void x86emuOp_mov_word_RM_SR(u8 X86EMU_UNUSED(op1))
{
    int mod, rl, rh;
    u16 *destreg, *srcreg;
    uint destoffset;
    u16 destval;

    START_OF_INSTR();
    DECODE_PRINTF("MOV\t");
    FETCH_DECODE_MODRM(mod, rh, rl);
    if (mod < 3) {
	destoffset = decode_rmXX_address(mod, rl);
	DECODE_PRINTF(",");
	srcreg = decode_rm_seg_register(rh);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	destval = *srcreg;
	store_data_word(destoffset, destval);
    } else {			 /* register to register */
	destreg = DECODE_RM_WORD_REGISTER(rl);
	DECODE_PRINTF(",");
	srcreg = decode_rm_seg_register(rh);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	*destreg = *srcreg;
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x8d
****************************************************************************/
void x86emuOp_lea_word_R_M(u8 X86EMU_UNUSED(op1))
{
    int mod, rl, rh;
    u16 *srcreg;
    uint destoffset;

/*
 * TODO: Need to handle address size prefix!
 *
 * lea	eax,[eax+ebx*2] ??
 */

    START_OF_INSTR();
    DECODE_PRINTF("LEA\t");
    FETCH_DECODE_MODRM(mod, rh, rl);
    if (mod < 3) {
	srcreg = DECODE_RM_WORD_REGISTER(rh);
	DECODE_PRINTF(",");
	destoffset = decode_rmXX_address(mod, rl);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	*srcreg = (u16)destoffset;
	}
    /* } else { undefined.  Do nothing. } */
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x8e
****************************************************************************/
void x86emuOp_mov_word_SR_RM(u8 X86EMU_UNUSED(op1))
{
    int mod, rl, rh;
    u16 *destreg, *srcreg;
    uint srcoffset;
    u16 srcval;

    START_OF_INSTR();
    DECODE_PRINTF("MOV\t");
    FETCH_DECODE_MODRM(mod, rh, rl);
    if (mod < 3) {
	destreg = decode_rm_seg_register(rh);
	DECODE_PRINTF(",");
	srcoffset = decode_rmXX_address(mod, rl);
	srcval = fetch_data_word(srcoffset);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	*destreg = srcval;
    } else {			 /* register to register */
	destreg = decode_rm_seg_register(rh);
	DECODE_PRINTF(",");
	srcreg = DECODE_RM_WORD_REGISTER(rl);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	*destreg = *srcreg;
    }
    /*
     * Clean up, and reset all the R_xSP pointers to the correct
     * locations.  This is about 3x too much overhead (doing all the
     * segreg ptrs when only one is needed, but this instruction
     * *cannot* be that common, and this isn't too much work anyway.
     */
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x8f
****************************************************************************/
void x86emuOp_pop_RM(u8 X86EMU_UNUSED(op1))
{
    int mod, rl, rh;
    uint destoffset;

    START_OF_INSTR();
    DECODE_PRINTF("POP\t");
    FETCH_DECODE_MODRM(mod, rh, rl);
    if (rh != 0) {
	DECODE_PRINTF("ILLEGAL DECODE OF OPCODE 8F\n");
	HALT_SYS();
    }
    if (mod < 3) {
	destoffset = decode_rmXX_address(mod, rl);
	if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	    u32 destval;

	    DECODE_PRINTF("\n");
	    TRACE_AND_STEP();
	    destval = pop_long();
	    store_data_long(destoffset, destval);
	} else {
	    u16 destval;

	    DECODE_PRINTF("\n");
	    TRACE_AND_STEP();
	    destval = pop_word();
	    store_data_word(destoffset, destval);
	}
    } else {			/* register to register */
	if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	    u32 *destreg;

	    destreg = DECODE_RM_LONG_REGISTER(rl);
	    DECODE_PRINTF("\n");
	    TRACE_AND_STEP();
	    *destreg = pop_long();
	} else {
	    u16 *destreg;

	    destreg = DECODE_RM_WORD_REGISTER(rl);
	    DECODE_PRINTF("\n");
	    TRACE_AND_STEP();
	    *destreg = pop_word();
	}
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x90
****************************************************************************/
void x86emuOp_nop(u8 X86EMU_UNUSED(op1))
{
    START_OF_INSTR();
    DECODE_PRINTF("NOP\n");
    TRACE_AND_STEP();
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x91-0x97
****************************************************************************/
void x86emuOp_xchg_word_AX_register(u8 X86EMU_UNUSED(op1))
{
    u32 tmp;

    op1 &= 0x7;

    START_OF_INSTR();

    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	u32 *reg32;
	DECODE_PRINTF("XCHG\tEAX,");
	reg32 = DECODE_RM_LONG_REGISTER(op1);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	tmp = M.x86.R_EAX;
	M.x86.R_EAX = *reg32;
	*reg32 = tmp;
    } else {
	u16 *reg16;
	DECODE_PRINTF("XCHG\tAX,");
	reg16 = DECODE_RM_WORD_REGISTER(op1);
	DECODE_PRINTF("\n");
	TRACE_AND_STEP();
	tmp = M.x86.R_AX;
	M.x86.R_EAX = *reg16;
	*reg16 = (u16)tmp;
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x98
****************************************************************************/
void x86emuOp_cbw(u8 X86EMU_UNUSED(op1))
{
    START_OF_INSTR();
    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	DECODE_PRINTF("CWDE\n");
    } else {
	DECODE_PRINTF("CBW\n");
    }
    TRACE_AND_STEP();
    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	if (M.x86.R_AX & 0x8000) {
	    M.x86.R_EAX |= 0xffff0000;
	} else {
	    M.x86.R_EAX &= 0x0000ffff;
	}
    } else {
	if (M.x86.R_AL & 0x80) {
	    M.x86.R_AH = 0xff;
	} else {
	    M.x86.R_AH = 0x0;
	}
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x99
****************************************************************************/
void x86emuOp_cwd(u8 X86EMU_UNUSED(op1))
{
    START_OF_INSTR();
    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	DECODE_PRINTF("CDQ\n");
    } else {
	DECODE_PRINTF("CWD\n");
    }
    DECODE_PRINTF("CWD\n");
    TRACE_AND_STEP();
    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	if (M.x86.R_EAX & 0x80000000) {
	    M.x86.R_EDX = 0xffffffff;
	} else {
	    M.x86.R_EDX = 0x0;
	}
    } else {
	if (M.x86.R_AX & 0x8000) {
	    M.x86.R_DX = 0xffff;
	} else {
	    M.x86.R_DX = 0x0;
	}
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x9a
****************************************************************************/
void x86emuOp_call_far_IMM(u8 X86EMU_UNUSED(op1))
{
    u16 farseg, faroff;

    START_OF_INSTR();
	DECODE_PRINTF("CALL\t");
	faroff = fetch_word_imm();
	farseg = fetch_word_imm();
	DECODE_PRINTF2("%04x:", farseg);
	DECODE_PRINTF2("%04x\n", faroff);
	CALL_TRACE(M.x86.saved_cs, M.x86.saved_ip, farseg, faroff, "FAR ");

    /* XXX
     *
     * Hooked interrupt vectors calling into our "BIOS" will cause
     * problems unless all intersegment stuff is checked for BIOS
     * access.	Check needed here.  For moment, let it alone.
     */
    TRACE_AND_STEP();
    push_word(M.x86.R_CS);
    M.x86.R_CS = farseg;
    push_word(M.x86.R_IP);
    M.x86.R_IP = faroff;
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x9b
****************************************************************************/
void x86emuOp_wait(u8 X86EMU_UNUSED(op1))
{
    START_OF_INSTR();
    DECODE_PRINTF("WAIT");
    TRACE_AND_STEP();
    /* NADA.  */
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x9c
****************************************************************************/
void x86emuOp_pushf_word(u8 X86EMU_UNUSED(op1))
{
    u32 flags;

    START_OF_INSTR();
    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	DECODE_PRINTF("PUSHFD\n");
    } else {
	DECODE_PRINTF("PUSHF\n");
    }
    TRACE_AND_STEP();

    /* clear out *all* bits not representing flags, and turn on real bits */
    flags = (M.x86.R_EFLG & F_MSK) | F_ALWAYS_ON;
    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	push_long(flags);
    } else {
	push_word((u16)flags);
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x9d
****************************************************************************/
void x86emuOp_popf_word(u8 X86EMU_UNUSED(op1))
{
    START_OF_INSTR();
    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	DECODE_PRINTF("POPFD\n");
    } else {
	DECODE_PRINTF("POPF\n");
    }
    TRACE_AND_STEP();
    if (M.x86.mode & SYSMODE_PREFIX_DATA) {
	M.x86.R_EFLG = pop_long();
    } else {
	M.x86.R_FLG = pop_word();
    }
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x9e
****************************************************************************/
void x86emuOp_sahf(u8 X86EMU_UNUSED(op1))
{
    START_OF_INSTR();
    DECODE_PRINTF("SAHF\n");
    TRACE_AND_STEP();
    /* clear the lower bits of the flag register */
    M.x86.R_FLG &= 0xffffff00;
    /* or in the AH register into the flags register */
    M.x86.R_FLG |= M.x86.R_AH;
    DECODE_CLEAR_SEGOVR();
    END_OF_INSTR();
}

/****************************************************************************
REMARKS:
Handles opcode 0x9f
****************************************************************************/
void x86emuOp_lahf(u8 X86EMU_UNUSED(op1))
{
    START_OF_INSTR();