[LinuxBIOS] LinuxBIOS messing with CMOS on reboot?
stepan at openbios.org
Sat Dec 3 23:21:56 CET 2005
* Eric W. Biederman <ebiederman at lnxi.com> [051203 22:28]:
> > writing the cmos from the file afterwards and rebooting is fine, so it's
> > not the cmos image that is wrong.
> > Could LinuxBIOS change the CMOS when doing a reboot?
> Possibly. The only safe way after a bios flash is to toggle the power.
Good point. I will try that to see if it changes the behaviour
> There are a couple of possibilities.
> - cmos_util needs to be explicitly told not to do the linuxbios checksum
i've used file_to_cmos and cmos_to_file to switch. This should not do
any checksumming at all..
> - cmos_util has had problems when asked to flash all of the cmos options.
> (Sigsegv ...)
it seems to work fine. 256 bytes (which should be less as an option,
because I don't necessarily want to set back the clock) Also, rereading
the file after amibios corrected the checksum presents an identical file
(only the time changed)
> - The high 128 bytes are only moderately standard so it may be you have
> a board that stores them differently. We should be ok for intel and
> amd chipsets.
It's an AMD k8 chipset. I wondered whether I failed to look at even
higher cmos values via 74/75 or something. but then again, LinuxBIOS
never touches anything except the low 128 bytes.
> And of course other mystic locations but I would exhaust the other possibilities
Power toggling seems a good start. Closed source proprietary software
sucks for customers. Unfortunately it might rather make them think in terms
of "bios is always complicated"
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