cramfs mpc8xx 2.4.18

Ruhland, Paul PRuhland at
Sat Feb 14 06:31:09 EST 2004

Without more information I can't really tell what is wrong.  Did you create
an mtd partition map for your flash (need this to use the mtdblock devices)?

I used to mount cramfs images from flash, but ran into problems every so
often with the cramfs root not decompressing correctly while reprogramming
other sectors.  So I switched to mounting the cramfs image as a ramdisk.
You just build the cramfs image as usual but mount is as a ramdisk when
booting the kernel (I use u-boot so I used mkimage to prep it for that

I've attached a patch against linuxppc_2_4_devel (2.4.23) which adds this
capability, if your interested.  It simply changes the ramdisk blocksize to
match cramfs blocksize if its mounting a cramfs root image.

-----Original Message-----
From: Lokesh Kumar [mailto:kumar.lokesh at]
Sent: Friday, February 13, 2004 1:33 PM
To: linuxppc-embedded at
Subject: cramfs mpc8xx 2.4.18

Hi Gurus,

I have a custom board running 2.4.18 with initrd. Now, I want to make cramfs
as root filesystem. When I built cramfs support in the kernel and gave it
root=/dev/mtdblock1 (where my cramfs in correct endian order is stored on
flash) rootfstype=cramfs, the kernel hangs. MTD support is built in the
kernel. If I build cramfs as module, then boot my kernel with initrd (ext2)
and then mount it (on say /mnt), I can read cramfs correctly.

I also looked at rd.c file in drivers/block and noticed that this is does
not have cramfs initrd support. Do I need this? What am I doing wrong?
Please help

Lokesh Kumar

-------------- next part --------------
A non-text attachment was scrubbed...
Name: linuxppc_2_4_devel-cramfs_ramdisk.patch
Type: application/octet-stream
Size: 2021 bytes
Desc: not available
Url : 

More information about the Linuxppc-embedded mailing list