[lkml]   [2001]   [Jul]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: reading/writing CMOS beyond 256 bytes?
In article <> you write:
> said:
>> Motherboard manufacturers who have rewritable BIOS chips now leave one
>> page (typically 64k) for startup parameters. This is erased and
>> written using the magic provided by the chip vendors.
>You often have to do chipset-specific magic to enable the WE and Vpp lines
>to BIOS flash chips. See drivers/mtd/maps/l440gx.c in my working tree for
>an example.

Another way might be to use the PnP BIOS to read and write the
ESCD tables. I wrote some code to do this a few years ago and
after beating up the code a bit more I can at least read the ESCD
tables from the BIOS. If anyone is interested in doing something
with the code it can be found at:

The advantage of using the PnP BIOS is that the PnP BIOS knows
about the format of the data in BIOS and how to do all the
chipset specific stuff. The disadantage is as usual that a lot
of BIOSes are buggy.


"Just how much can I get away with and still go to heaven?"
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:56    [W:0.096 / U:0.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site