Stefan Reinauer firstname.lastname@example.org writes:
I'm seeing a weird problem while switching back and forth between a legacy bios and LinuxBIOS.
I have a 256 byte cmos image created with cmos_util and a 512k bios image for each firmware flavour.
Switching from legacy bios to LinuxBIOS works fine using flashrom and cmos_util.
Switching the other way round always leaves legacy bios with a wrong checksum on the first boot.
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.
Or is legacy bios doing some very weird things like safing additional data in mystic places?
There are a couple of possibilities. - cmos_util needs to be explicitly told not to do the linuxbios checksum calculation. - cmos_util has had problems when asked to flash all of the cmos options. (Sigsegv ...) - 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.
And of course other mystic locations but I would exhaust the other possibilities first.