Re: [PLUG] memory problem

[Bill Jonas <bj@netaxs.com>]

On Tue, 15 Aug 2000, michael white wrote:

>So, it looks to me like LINUX just isn't seeing all of my memory.

(Skip a paragraph to get straight to the answer.)

This is because some BIOSes are buggy.  Without getting too bogged down
in details, there are 3 ways (if I'm not mistaken) for the BIOS to
report the amount of memory to the OS.  The first (and oldest of the
three) has a limitation in that it can't report more than 64 megs.  The
second, I believe is not well documented and was ironed out by Microsoft
and the BIOS manufacturers; as such, Linux doesn't have a reliable way
to use it, and guesses conservatively (bad things happen if the OS tries
to access physical memory that isn't there).  The third way is more of a
standard, but not every motherboard/BIOS combination uses it.

What you want to do is this: As root, edit /etc/lilo.conf with your
favorite editor, and add a line after each Linux stanza that looks like:
append = "mem=xxxM" where "xxx" is the number of megabytes of *physical*
RAM you have.  I noticed this problem on a company machine I have; the
relevant parts of my /etc/lilo.conf look like this (the machine has 256 
megs of physical memory):
image=/vmlinuz
        label=Linux
        root=/dev/hda5
        read-only
        append = "mem=256M hdc=ide-scsi"
image=/vmlinuz.old
        label=Linux-old
        root=/dev/hda5
        read-only
        append = "mem=256M"
(The hdc=ide-scsi is for an IDE CD-RW drive, so don't add that unless
you have one.)

After you do this, run LILO (/sbin/lilo) as root, and reboot.

Hope that helps.

Bill
-- 
>Ever heard of .cshrc?             | "Linux means never having to delete
That's a city in Bosnia. Right?    |  your love mail." -- Don Marti
(Discussion in comp.os.linux.misc  |  http://www.billjonas.com/
on the intuitiveness of commands.) |  http://www.harrybrowne.org/


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