2002-09-26 18:31:46

by Michael D. Crawford

[permalink] [raw]
Subject: cramfs: wrong magic when loading ramdisk from floppy

I'm trying to load a cramfs filesystem as a ramdisk from a floppy. After I am
prompted to insert the floppy with the ramdisk image, and the kernel
acknowledges that it found a compressed image, I get the message:

cramfs: wrong magic

and then the kernel panics.

What I am trying to do is to use a regular PC to estimate the amount of RAM and
flash ROM an embedded project will require, so I'm loading a cramfs image from
floppy that will be similar to the cramfs image that will be loaded into flash.
I'm also booting a kernel with only enough options selected to boot and use
the console, ramdisk, cramfs and floppy disk. It's otherwise a stock 2.4.19 kernel.

I added a line to fs/cramfs/inode.c to print out the magic that it's seeing, and
it is 0xf6f6f6f6, which is not correct.

I'm using syslinux on a FAT floppy for my bootloader. The contents of
syslinux.cfg are:

DEFAULT linux root=/dev/fd0 init=/bin/sh load_ramdisk=1 prompt_ramdisk=1

Thanks for any help you can give me.


Michael D. Crawford
GoingWare Inc. - Expert Software Development and Consulting
[email protected]

Tilting at Windmills for a Better Tomorrow.