Booting Linux on 16 Meg DiskOnChip 2000

Carson, Jon A. JACarson at addcoinc.com
Wed May 9 15:22:34 EDT 2001


Hi All,

I need some help....HELP....as the subject line says, I am trying to boot 
Linux on a 16 Meg DiskOnChip 2000. Since I have a lot of information to 
give, this email will be a little terse,...sorry.

I have (apparently) sucsessfully formatted, fdisk'ed and ext2 filesystem'ed
it. The mount
point I chose was /doc. I then put a directory hierarchy on it resembling a
Linux distro. At this
point, I copied over the nftl* and mtd* drivers to /doc/dev.

I built a kernel choosing to build in all of the MTD/NFTL drivers into the
kernel ( not as modules ).
The Kernel is version 2.4.3 was downloadded from ftp.kernel.org.  Everything
seems to build
great,...no whining.   I used lilo-mtd to install the new kernel into the
DiskOnChip.

The problem I am having is that the kernel can't seem to find the root
filesystem on /dev/nftla1.  When the
kernel finally comes to a screeching halt, the last 4 lines of output are:

request module [block-major-3]: root fs not mounted
VFS: cannot open root device "" or 03:03 
please append a correct "root=" boot option
Kernel Panic: VFS: unable to mount root fs on 03:03

I am really confused by this because nothing I have done points to this
filesystem ( 03:03 aka /dev/hda3 ),
although this just happens to be my main development hard drive.  Another
interesting thing
is that there appears to be a NULL string somewhere ( see line #2 above ).

Here is my /doc/etc/lilo.conf:

	boot=/dev/nftla
	image=/doc/boot/docmtd243
	label=DOC-2.4.3-yaya
	root=/dev/nftla1

Since I have instructed lilo to use /dev/nftla , I have not marked the
partition as bootable ( primary partition #1 ).

Here is my lilo incantation, whilst booted onto /dev/hda3, and having
mounted the DOC:

# cd /doc/sbin
# ./lilo-mtd -v -C /doc/etc/lilo.conf -i /doc/boot/boot.b-mtd -m
/doc/boot/map

Here is what happens when the above incantation is executed, indented for
clarity:

	Warning: /dev/nftla is not on the first disk
	Patched LILO for M-Systems' DiskOnChip 2000
	LILO version 21, Copyright 1992-1998 Werner Almesberger

	Reading boot sector from /dev/nftla
	Merging with /doc/boot/boot.b-mtd
	Boot image: /doc/boot/docmtd243
	Added DOC-2.4.3-yaya *
	/boot/boot.5D00 exists - no backup copy made.
	Writing boot sector.

Everything seems to have gone well with lilo-mtd, but when the kernel boots,
it seems like it wants
to phone home over to /dev/hda3.  If I hadn't disabled IDE in the kernel ,
it would actually continue to 
boot the /dev/hda3 root filesystem.

Please note the reference to "/boot/boot.5D00 exists - no backup copy
made.".  This does not point
to /dev/nftla ( as it should ) , but /dev/hda3.

Is this a bug in lilo-mtd , or am I doing something wrong ?

I follow this list somewhat regularly and I nave not seen much information
on this subject.  If anybody out there
has a good recipe for booting DiskOnChip 2000 as a stand alone item, PLEASE,
share it with me.

Thanks in advance,
Jon Carson
ADDCO Inc.










More information about the linux-mtd mailing list