[coreboot] SeaBIOS, serial output, and grub
Ward Vandewege
ward at gnu.org
Fri May 1 23:45:51 CEST 2009
On Thu, Apr 30, 2009 at 10:39:31PM -0400, Kevin O'Connor wrote:
> On Thu, Apr 30, 2009 at 10:26:56PM -0400, Kevin O'Connor wrote:
> > What's really odd, is that if I have sgabios on, then grub does work
> > okay. I didn't catch this last night because I was also playing with
> > sgabios at the same time. As a guess, sgabios is reinitializing the
> > serial port back to a way grub is okay with. This may be specific to
> > qemu, but it's something to look into.
>
> Oops - if qemu/coreboot/seabios/sgabios/grub, then sgabios forwards
> the grub screen over serial - grub itself still wont talk to the
> serial directly. (If I run qemu/seabios/sgabios/grub then I get two
> copies of the grub messages - one from grub serial and one from grub
> screen via sgabios.)
Hmm. I'm not seeing that on h8dme. This is my cbfs:
./cbfstool ./coreboot.rom print
coreboot.rom: 1024 kB, bootblocksize 266240, romsize 1048576, offset 0x0
Alignment: 16 bytes
Name Offset Type Size
normal/payload 0x0 payload 65635
fallback/payload 0x10090 payload 65635
pci1002,515e.rom 0x20130 0x00000000 45056
genroms/sgabios.rom 0x2b170 0x00000000 3169
pci10de,0373.rom 0x2be10 0x00000000 57344
I've got a vga rom and gpxe in there, in addition to sgabios.
Here's a boot log (seabios head, coreboot r4232 + Myles' serial patch from
4241):
http://ward.vandewege.net/coreboot/h8dme/seabios20090501-sgabios-gpxe-grub-serial-fails.log
And here's one without gpxe in the cbfs:
http://ward.vandewege.net/coreboot/h8dme/seabios20090501-sgabios-grub-serial-fails.log
Basically, grub's super slow, trying to write to serial, but as you can see
no grub output ever appears there. Sometimes grub actually displays its menu
on the vga console after the 'press any key to continue' lines (if I bang
enough keys, it seems), but most of the time it just does the default, which
is (nonfunctioning) serial.
Thanks,
Ward.
--
Ward Vandewege <ward at fsf.org>
Free Software Foundation - Senior Systems Administrator
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