On Tue, Sep 30, 2014 at 7:06 AM, Kevin O'Connor <kevin(a)koconnor.net> wrote:
On Mon, Sep 29, 2014 at 11:27:33PM -0600, Marc Jones
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)
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
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.