[SeaBIOS] vgabios testing

[Gerd Hoffmann]

On 03/05/12 23:20, Kevin O'Connor wrote:
> On Mon, Mar 05, 2012 at 08:10:41AM +0100, Gerd Hoffmann wrote:
>> On 03/04/12 20:06, Kevin O'Connor wrote:
>>> On Fri, Mar 02, 2012 at 10:09:10AM +0100, Gerd Hoffmann wrote:
>>>> Did some more testing of the vgabios today, two issues popped up:
>>>>
>>>>   (1) screen isn't cleared in some cases.  Visible with grub1 in text
>>>>       mode.  When it displays the menu a few stray chars are visible.
>>>>       Even more obvious it becomes when hitting 'c' then to get a
>>>>       prompt, then alot of the menu is still visible.
>>>
>>> Thanks.  Can you point me to an image and/or the steps to reproduce?
>>> I've tracked down a few of these before, and I'm sure I can fix it if
>>> I can reproduce it.
>>
>> Install fedora 15 (or older) in qemu (mimimal is enougth).  Edit
>> /boot/grub/menu.lst and comment out the splashimage and hiddenmenu
>> lines.  On next reboot grub will come up in text mode and you'll see the
>> behavior described above.
> 
> I couldn't reproduce the issue on the initial screen, but I can
> reproduce when hitting the 'c' key.  Turns out to be an integer
> overflow issue - patch below.

Fixes it.

thanks,
  Gerd