Newbie - JFFS as Root FS

[Michael Rothwell]

Have you trid telling the kernel which block device to use? Something like
"blkmtd_device=/dev/hda1"

I have JFFS2 on a CF card (/dev/hda2 on this machine), mounting as root.
/boot (/dev/hda1) is ext2, though; I'm using regular lilo to boot.

-M

----- Original Message -----
From: <Sheela.Kashyap at radisys.com>
To: <linux-mtd at lists.infradead.org>
Sent: Friday, December 28, 2001 6:27 PM
Subject: Newbie - JFFS as Root FS


> Hi,
>
> I am relatively new to Linux and definitely new to MTD/JFFS. We have a
> motorola 8xx board, the boot loader used is ppcboot. We are currently
using
> NFS as the root file system.  The kernel has been compiled with the right
> JFFS and MTD options. I am able to erase the MTD device, copy the file
> system on to it and mount and umount multiple times without any problems.
> The kernel is in the flash.  We are using Dhcp to figure out its IP
> address.
>
> When I set the bootargs in ppcboot to "root=/dev/mtdblock1 rw" or
> "root=/dev/mtdblock1 rw ip=10.100.4.44" and try booting the kernel,
> everything is fine till it comes time to mount the root FS.It still seems
> to try and go out on the net. This is the trace I see. I have cut out some
> parts to reduce the clutter.
>
> --------------------------------------------------------------------------
---------------------------------------------------------------
>
>
> Initializing...
>   CPU:   XPC860xxZPnnD4 at 80 MHz: 16 kB I-Cache 8 kB D-Cache FEC present
>   Board:   DRAM:  About to program UPMB... finished programming UPMB
> Setting value for MPTPR to 400
> Run precharge command for each chip-select used
> <snip...>
>
> cas latensies supported          3  2
> <snip...>
>
> ppcboot->printenv
> bootdelay=10
> baudrate=19200
> ipaddr=10.0.0.77
> serverip=10.0.0.128
> bootcmd=bootm 28080000
> stdin=serial
> stdout=serial
> stderr=serial
> bootargs=root=/dev/mtdblock1 rw ip=10.100.4.44
>
> SWSE(bootrom)->bootm 28080000
> ## Booting Linux kernel at 28080000 ...
>    Image Name:   HHL 2.0 for SWSE version 0.005
>    Created:      2001-12-06   5:07:40
>    Image Type:   PowerPC Linux Kernel Image (gzip compressed)
>    Data Size:    550042 Bytes = 537 kB = 0 MB
>    Load Address: 00000000
>    Entry Point:  00000000
>    Verifying Checksum ... OK
>    Uncompressing Kernel Image ... OK
> ## Transferring control to Linux (at address 00000000) ...
> Linux version 2.4.2_hhl20 (rick at localhost.localdomain) (gcc version 2.95.3
> 20010
> 315 (release/MontaVista)) #6 Wed Dec 5 21:03:08 PST 2001
> On node 0 totalpages: 65536
> zone(0): 65536 pages.
> zone(1): 0 pages.
> zone(2): 0 pages.
> Kernel command line: root=/dev/mtdblock1 rw ip=10.100.4.44
> Decrementer Frequency = 300000000/60
>
> <snip....>
>
> JFFS version 1.0, (C) 1999, 2000  Axis Communications AB
> loop: loaded (max 8 devices)
> physmap flash device: 1780000 at 28880000
> Physically mapped flash: Found 2 x16 CFI devices at location 0 in 16 bit
> mode
> JEDEC ID: 89 18
> cstm_cfi_jedec flash device: 1780000 at 28880000
> MTD flash: Found 2 x16 CFI devices at location 0 in 16 bit mode
> JEDEC ID: 89 18
> NET4: Linux TCP/IP 1.0 for NET4.0
> IP Protocols: ICMP, UDP, TCP, IGMP
> IP: routing cache hash table of 2048 buckets, 16Kbytes
> TCP: Hash tables configured (established 16384 bind 16384)
> Sending BOOTP requests............. timed out!
> IP-Config: Auto-configuration of network failed.
> NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
> Root-NFS: No NFS server available, giving up.
> VFS: Unable to mount root fs via NFS, trying floppy.
> request_module[block-major-2]: Root fs not mounted
> VFS: Cannot open root device "mtdblock1" or 02:00
> Please append a correct "root=" boot option
> Kernel panic: VFS: Unable to mount root fs on 02:00
> Rebooting in 180 seconds..
>
> --------------------------------------------------------------------------
------------------------------
>
> The "Sending BOOTP requests" line is what I don't understand. The kernel
> obviously does not figure out that the root filesystem to be used is
> 'jffs'. How can I get it to do that? Do I need to make changes to some
> kernel files? Or is it that I need to change the kernel so that it detects
> the MTD block device first and figures out the filesystem?
>
> Any help is greatly appreciated.
>
> Thanks,
> Sheela.
>
>
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