Re: i486 emu in mainline?

[Maciej W. Rozycki]

On Sun, 23 May 2004, Christoph Hellwig wrote:

> +			/* we'll verify if this is a BSWAP opcode, main source of SIGILL on 386's */
> +			if ((*eip & 0xF8) == 0xC8) {  /* BSWAP */
> +				u8 reg;
> +
> +				reg = *eip++ & 0x07;
> +				src = reg_address(regs, 1, reg);
> +				
> +				__asm__ __volatile__ (
> +						      "xchgb %%al, %%ah\n\t"
> +						      "roll $16, %%eax\n\t"
> +						      "xchgb %%al, %%ah\n\t"
> +						      : "=a" (*(u32*)src)
> +						      : "a" (*(u32*)src));
> +				regs->eip = (u32)eip;
> +				goto out;
> +			}

 You've forgotten about the 16-bit variant here -- the emulation is wrong 
with PREFIX_D32.  This may not matter much in practice, though.

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@xxxxxxxxxxxxx, PGP key available        +
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