Re: 2.0.0/2.0.25 oopses with buslogic 956C and two 4G seagates ...

Peter T. Breuer (
Sun, 17 Nov 1996 14:59:08 +0000 (WET)

"A month of sundays ago Philip Blundell wrote:"
> On Sun, 17 Nov 1996, Peter T. Breuer wrote:
> > (if anyone already knows how to make a S/w bootdisk with a
> > decompressing ramdisk, please let me know :-).
> It's quite easy. Build your kernel with ramdisk enabled. Build your
> filesystem image (I use the loopback filesystem for this), and compress
> it.


I had already taken the buslogic boot disk, mounted it as minix on /mnt,
blammed my kernel onto it, added append="load_ramdisk=1 prompt_ramdisk=1"
to its lilo.conf (upgraded my lilo and ...) and ran lilo -r /mnt -b /dev/fd0
on it.

This works - i.e. it mounts a separate rootdisk into ram - but it doesn't
know how to decomopress the image. So I just decompressed a rootdisk and
it goes. I'd like to know the decompress trick ..

> Pick a start offset on the disk for the filesystem. This has to be large

But I want a FS on a _separate_ floppy. Do I therefore keep with offset 0?

> enough that it starts after the kernel finishes, and small enough that the
> filesystem will fit. Obviously the total size of kernel+compressed image
> has to be smaller than the size of your disk.
> Then use dd to write the filesystem onto the disk:
> # dd if=filesystem.gz of=/dev/fd0 bs=1024 seek=nnn
> where nnn is the offset you chose. When you boot your kernel, give it
> "ramdisk_start=nnn" and off you go. You can do this with LILO on the boot
> disk, or by hardwiring the value into the kernel image (with rdev).

I see. It looks to me as though what I already did should have worked
modulo some playing with offsets. It may be that the slackware
bootdisks are compressed at an offset, because my trick couldn't mount
the (compressed) bootdisks and I was using the default offset of zero.
Heck - what am I saying. They must be compressed at offset zero or I
couldn't have decomporessed them. I don't get it. Time for one more go.

> phil

Peter T. Breuer
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