Re: [Qemu-devel] PC machine types switched to SeaBIOS/gPXE

[Avi Kivity]

On 11/03/2009 08:02 AM, Kevin O'Connor wrote:
> On Tue, Nov 03, 2009 at 07:01:52AM +0200, Avi Kivity wrote:
>    
> > That works too, but if firmware config can use rep/ins, that's one less
> > interface we have to add.
> >      
> The following patch to seabios seems to work.  I'm not sure if there
> are any special implications to qemu.
>
> -Kevin
>
>
>
> --- a/src/paravirt.c
> +++ b/src/paravirt.c
> @@ -23,8 +23,7 @@ qemu_cfg_select(u16 f)
>   static void
>   qemu_cfg_read(u8 *buf, int len)
>   {
> -    while (len--)
> -        *(buf++) = inb(PORT_QEMU_CFG_DATA);
> +    insb(PORT_QEMU_CFG_DATA, buf, len);
>   }
>    

Should make sure to use the 32-bit address size version so we use ecx, 
not cx, in case len doesn't fit in 16 bits.

--
Do not meddle in the internals of kernels, for they are subtle and quick to 
panic.