Booting from DOC2000 with GRUB loader

[John Sutton <john@scl.co.uk>]

Hi all (and Russ in particular)

I've got the same problem as previous post on this subject:

---------------------------------------
On Thu, 2002-04-25 at 19:19, Zhiwei Yu wrote:
> Hi,
> 
> I am working on booting from DOC2000, LILO works on my
> box but GRUB doesn't.  After I patched the latest
> patch for GRUB, I got grub-fireware and sucessfully
> load the fireware in DOC.
> 
> For now, everytime I boot up, I got grub prompt, but I
> failed to load kernel, the command I using is 
> kernel (dc0,0)/boot/bzImage.
> 
> This problem is not new to the list, I found several
> similar mails, All of them didn't have the answer.  DI
> u have any idea?  Thanks in advance.

probably because you overwrote some nftl stuff with grub. Erase the
whole thing (eraseall /dev/mtd0), put grub on it, find the next free
block directly past grub and nftl_format at that offset. fdisk your
nftla, mkfs the partition, add the kernel, and maybe a menu.lst.
----------------------------------------------

My question is: *how* do I "find the next free block directly past grub"?

When I put grub on there (not at that stage realising I was going to trash my
existing nftl partitions and so I omitted to record the output), I *seem to*
recall that doc_loadbios reported needing 6 x 16k "blocks" to store the grub
firmware - which fits, because the grub_firmware file is 87k.

So, in what units is the <start offset> argument to nftl_format?  i.e. do I do :

   nftl_format /dev/mtd0 6   (16k blocks)

or nftl_format /dev/mtd0 96   (1k blocks)

or nftl_format /dev/mtd0 98304  (bytes)

etc...?

I'm nervous about messing this up because since I put grub on the DoC, the
machine only ever boots from the DoC - completely ignores floppy, scsi disks
and cdrom.  So if I screw up this nftl_format and trash grub, I'm going to end
up with an unbootable system ;-(  (OK, I'll just have to pull the DoC chip out
of the board *again*, but even this gives me the eebies, so tight is the damn
thing stuck in its socket!  And anyway, if the system is unbootable with the
DoC chip in there, how am I ever going to reprogram it?)

Help much appreciated!

TIA
John

***************************************************
John Sutton
SCL Internet
URL http://www.scl.co.uk/
Tel. +44 (0) 1239 711 888
***************************************************