[Qemu-devel] Re: [PATCH] extboot: properly set int 0x13 return value

[Avi Kivity <avi@redhat.com>]

Glauber Costa wrote:
> Callers of int 0x13 usually rely on the carry flag being
> clear/set to indicate the status of the interrupt execution.
>
> However, our current code clear or set the flags register,
> which is totally useless. Whichever value it has, will
> be overwritten by the flags value _before_ the interrupt, due to
> the iret instruction.
>
> This fixes a bug that prevents slackware (and possibly win2k, untested)
> to boot.
>
>   

Applied, thanks.

>  
> -.macro clc
> -	push %ax
> -	pushf
> -	pop %ax
> -	and $(~FLAGS_CF), %ax
> -	push %ax
> -	popf
> -	pop %ax
>   

Anthony, any reason you did not use the 'clc' instruction instead of a 
macro?

-- 
error compiling committee.c: too many arguments to function