Re: K7 on SD11 and 2.2.17: memory not detected

From: Erik Mouw (J.A.K.Mouw@ITS.TUDelft.NL)
Date: Wed Oct 11 2000 - 12:08:30 EST

On Wed, Oct 11, 2000 at 12:01:23PM -0500, Sudhindra Herle wrote:
> > The BIOS E801 memory reporting is buggy on a lot of these
> > boards. Since the
> > vendors dont appear to care you probably want to pass
> > mem=383M or mem=384M
> > depending if the BIOS uses top of memory for stuff on boot
> How would one know if the BIOS uses the upper MB of memory? I poked around
> in the BIOS and most of the "shadow" and "cacheable" things are disabled.

If the BIOS has ACPI support, it uses some blocks in the upper MB of

> Also, is there someone maintaining a list of such known bugs for
> CPU+motherboard combo? If there is no-one, I'll be happy to maintain the
> list.

If you do, put the IBM ThinkPad 600X on it: BIOS e820 memory reporting
is broken, and the machine puts its ACPI tables at the top of memory,
so you have to use "mem=(installed - 1)M" to use it or otherwise the
first ACPI event crashes the system.


J.A.K. (Erik) Mouw, Information and Communication Theory Group, Department
of Electrical Engineering, Faculty of Information Technology and Systems,
Delft University of Technology, PO BOX 5031,  2600 GA Delft, The Netherlands
Phone: +31-15-2783635  Fax: +31-15-2781843  Email:
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