[SeaBIOS] cbvga
Marc Jones
marcj303 at gmail.com
Tue Sep 30 20:40:26 CEST 2014
On Tue, Sep 30, 2014 at 7:06 AM, Kevin O'Connor <kevin at koconnor.net> wrote:
> On Mon, Sep 29, 2014 at 11:27:33PM -0600, Marc Jones wrote:
>> I'm trying to use the cbvga after a coreboot has initialized graphics.
>> It looks like everything is fine, but I don't get any seabios text on
>> the screen. It seems that int10 isn't working. Grub is able to display
>> fine. Does anyone know if Grub uses int10 or direct b8000 accress?
>>
>> Scan for VGA option rom
>> Running option rom at c000:0003
>> Start SeaVGABIOS (version ?-20140929_231635-megaman)
>> enter vga_post:
>> a=00000000 b=0000ffff c=00000000 d=0000ffff ds=0000 es=f000 ss=0000
>> si=00000000 di=000087b0 bp=00000000 sp=00006e62 cs=f000 ip=d413 f=0000
>> coreboot vga init
>> Found FB @ c0000000 1024x768 with 16 bpp (2048 stride)
>> set VGA mode 140
>> Attempting to allocate VGA stack via pmm call to f000:d46a
>> pmm call arg1=0
>> VGA stack allocated at ef590
>> Turning on vga text mode console
>> set VGA mode 3
>> SeaBIOS (version ?-20140929_231635-megaman)
>
> You don't see any output from SeaBIOS (no version banner and no boot
> menu prompt)?
>
> Is the framebuffer really at 0xc0000000 (as the log reports) or at
> 0xb8000 (as your question states)? In my tests grub uses int10
> instead of 0xb8000, but if it detects a vbe adapter it will setup a
> graphical framebuffer and then write to that. Do you see seavgabios
> debug messages showing grub probing for vbe later in the log? Is the
> grub output you do see in graphics mode or text mode?
I don't get any output from SeaBIOS. The framebuffer is at 0xc0000000.
I asked about b8000 since that is the legacy area and I wasn't certain
how grub does things. I didn't capture any additional ouptut while
grub was loading. I assume that it is doing the vbe setup as you said.
I can do some additional debug and instrument the int10s.
Thanks for the tips.
Marc
>
> -Kevin
--
http://se-eng.com
More information about the SeaBIOS
mailing list