Re: [Qemu-devel] Re: Detecting an assembly instruction in QEMU

["Atif Hashmi" <atifhashmi@gmail.com>]

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Hi Eduardo,

I really appreciate your help but there is a small think that I need to ask
you.

In target-i386/translate.c, there are many variants of mov i.e.
 case 0x89: /* mov Gv, Ev */
 case 0xc7: /* mov Ev, Iv */
 case 0x8b: /* mov Ev, Gv */
 case 0x8e: /* mov seg, Gv */

which one do you think will be called when "mov %eax, %eax" instruction is
translated.
I printed the value of modrm inside the case 0x89 but the value remains the
same whether I use %eax or %ebx.

Secondly, How can I extract the source and destination registers from modrm.

I will really appreciate your help.

Thanks,
Atif


On 4/6/07, Eduardo Felipe <edusaper@gmail.com> wrote:
>
> Hi,
>
> Your should create a new helper function in \target-i386\helper.c to
> perform whatever you want QEMU to do when movl %eax,%eax is found.
>
> To invoke that function create a new opcode in \target-i386\op.c. That
> opcode should only call your helper function.
>
> Finally, modify \target-i386\translate.c to generate your opcode when movl
> %eax,%eax is translated. Look for the string 0x89, you can find out target
> and source registers of the move operation from variable modrm, so only %eax
> is considered.
>
> Regards,
> Eduardo
>
>
>

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