This last week I added an additional 16 MB of memory to my 486/DX2
system for total of 32 MB. I came up with what I thought was an
unusual problem. With this additional memory installed, the system
would not boot. It kept stopping at the "VFS: Mounted root (ext2
filesystem) readonly" message. This is at the point that init is
started.
I played around with hardware and lilo options and discovered that
the system would boot okey if I either used the kernel boot command
option of "mem=16m", or if I turned off the hardware external cache.
Neither of these options were very good. So I limped along and
read some linux mail from vger.rutgers.edu. I do not remember which
piece of mail it was that I read, because that mail had already hit
the bit bucket, but some discussion that was being carried on finally
sank into my brain about adjusting memory options during the boot
phase of the system to compensate for this kind of a hardware problems.
What I found out was that if I told the kernel I had 384 KB less
than what I really had, the system would boot with nearly all of the
available 32 MB of memory, and the external cache as well.
I do not know why I cannot use the last 384 KB of memory. Maybe the
hardware is relocating something it needs to upper memory. The point
as I see it is that this kind of a problem demonstrates a variation
in way that motherboards are designed. Linux needs to be able to
work with as many of these different variations as it can if it is to
be a successful operating system.
Bill
-- William M. Perkins Internet - wperkins@us.net The Greenwood or - bill@cais.com Commodore is dead. Long lives the Amiga! (AmigaOS/Linux/NetBSD)