Date:	Wed, 29 Mar 2000 04:06:08 -0800 (PST)
From:	Andre Hedrick <andre@linux-ide.org>
To:	"H. Peter Anvin" <hpa@transmeta.com>
Subject: Re: Answer (Re: Cylinder limits jumper for drives over 32GB)

On Tue, 28 Mar 2000, H. Peter Anvin wrote:

> Andre... what we're trying to figure out if there is a way to this
> *TRANSIENTLY*, so that a reset will set it back to the old value.
> 
> However, if plugging in manual values in the BIOS works then that's
> probably the recommended way, unless there really is an easy way to work
> around.
> 
> Remember... most hardware/firmware is broken.  Part of what makes a good
> OS is to work with broken hardware without sacrificing working with
> properly working hardware.  God knows I've messed lots with BIOS bugs.

Peter,

Please trust that I know the world is full of broken hardware, and even
if you follow the exact OEM directions for the hardware, it still can go
wrong.  I see some of the worst night/day-mares in ATA hardware than
anyone can imagine.

There is only three possible solutions for the 05/14/99 (and older) AWARD
BIOS problem........

1) Users purchase an ADD-ON card that will handle the large drives.

2) Users issues a bogus geometry to the BIOS and we ignore it and use the
entire disk.

3) Users runs OEM capacity shrinking tool. Depend on Linux to issue
READ/SET_MAX_ADDRESS and update the values "soft" and not clobber the
"protected memory area".  In principle, a reboot/power-cycle will revert
the capacity back to 32GB so that one may reboot with out a hang.

This is the preferred order in my book.

FYI, I am working with the ADD-ON card manufacturers to get them to
correct their BIOS code to prevent this problem.

Cheers,

Andre Hedrick
The Linux ATA/IDE guy


I only got wierded out because of potential partition fragmentation if any
goes wrong.


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