[coreboot] SGABIOS checksum [kevin at koconnor.net: Re: SeaBIOS, serial output, and grub]

Peter Stuge peter at stuge.se
Thu May 14 15:38:33 CEST 2009

Hi Nathan,

there was some discussion on the coreboot mailing list, and it seems
that the SGABIOS binary doesn't have a checksum calculated for it,
which means that some BIOSes refuse to initialize it.

The SeaBIOS project maintained by Kevin has a utility for calculating
checksums, available at:


Kevin, I can't find that buildrom.py script in seabios.git?


----- Forwarded message from Kevin O'Connor <kevin at koconnor.net> -----

From: Kevin O'Connor <kevin at koconnor.net>
To: coreboot at coreboot.org
Subject: Re: [coreboot] SeaBIOS, serial output, and grub
Date: Thu, 14 May 2009 09:19:33 -0400

On Wed, May 13, 2009 at 11:23:52PM -0400, Ward Vandewege wrote:
> > which is correct (the last two digits are 00).
> Huh:
> $ v ../payloads/sgabios.bin 
> -rwxr-xr-x 1 root src 3169 2009-04-29 13:56 ../payloads/sgabios.bin*
> $ tools/checksum.py <../payloads/sgabios.bin 
> sum=50b76

Heh - sgabios isn't properly checksumming.  It was just dumb luck that
my binary summed to zero.

This is a hack, but you can use seabios' rom building tool to make it

tools/buildrom.py ../payloads/sgabios.bin sgabios-cksum.bin

Someone should follow up with google on this..


coreboot mailing list: coreboot at coreboot.org

----- End forwarded message -----

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