[LinuxBIOS] cmos checksum in linuxbios table

Stefan Reinauer stepan at openbios.org
Sat Dec 3 22:08:42 CET 2005

Hi Yinghai,

Tools like LNXI's cmos_util and Dave Peterson's lxbios usually need
the cmos.layout file to be able to change CMOS settings.

The settings themselfes are stored in the LinuxBIOS table. The location
of the checksum is also stored. But there's no way to find out what 
area has to be checksummed. So these tools fail without cmos.layout.

Thus someone implemented a LinuxBIOS table entry type
LB_TAG_OPTION_CHECKSUM to pack this information into the LinuxBIOS table
as well.

But LinuxBIOS never created such an entry. I noticed this after
implementing reading this table entry in lxbios (lxbios.sourceforge.net)

If an LB_TAG_OPTION_CHECKSUM entry is created (which the patch does)
cmos.layout is not needed as an extra file to change cmos settings.
Everything can be read from the LinuxBIOS table.


* yhlu <yinghailu at gmail.com> [051203 20:49]:
> then who will check the checksum?
> YH
> On 12/3/05, Stefan Reinauer <stepan at openbios.org> wrote:
> > Hi,
> >
> > I suggest putting the cmos checksum areas into the LinuxBIOS table.
> > This was obviously planned a long time ago and I already implemented
> > support for that in the lxbios utility.
> >
> > See below patch to implement this thing in LinuxBIOS.
> >
> > Stefan

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