Booting from DOC2000 with GRUB loader

Booting from DOC2000 with GRUB loader

[John Sutton]

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
***************************************************

Re: Booting from DOC2000 with GRUB loader

[Ilguiz Latypov]

Hi John,

On Wed, 1 May 2002, John Sutton wrote:

> or nftl_format /dev/mtd0 98304  (bytes)

The third option is the right one.  The start offset of the NFTL layer
must be specified in bytes.

> And anyway, if the system is unbootable with the DoC chip in there, how
> am I ever going to reprogram it?)

Install GRUB or LILO on your hard disk.  Insert the DOC chip when you've
gotten to the boot prompt.

Ilguiz

Re: Booting from DOC2000 with GRUB loader

[Nikhil Goel]

 From the commands pondered upon -

	nftl_format /dev/mtd0 98304

works fine for me in a similar setup. The same was given as a reference, 
the first time the grub and DOC2000 patch showed up.



John Sutton wrote:
> 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
> ***************************************************
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
> 
> 

Re: Booting from DOC2000 with GRUB loader

[Russ Dill]

 
> or nftl_format /dev/mtd0 98304  (bytes)

this one is correct

> 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!

*** WARNING *** WARNING *** WARNING *** WARNING ***

THIS CAN DAMAGE YOUR HARDWARE AND BLOW YOU UP
(but it seems to work for me)

*** WARNING *** WARNING *** WARNING *** WARNING ***

I have an ISA card for the DOC2000, I boot up my workstation, carefully
plug in the isacard, modprobe doc2000, insmod docprobe insmod mtdchar
(if necessary) insmod nftl (if necessary). Do whatever I need to do,
rmmod nftl, rmmod docprobe, rmmod doc2000, and remove the card. On my
machine, doing this using the devfsd nodes causes an oops after the
first time, a simple workaround is using hand made device files.

*** WARNING *** WARNING *** WARNING *** WARNING ***

THIS CAN DAMAGE YOUR HARDWARE AND BLOW YOU UP
(but it seems to work for me)

*** WARNING *** WARNING *** WARNING *** WARNING ***

Re: Booting from DOC2000 with GRUB loader

[John Sutton]

Hi again

Many thanks for all that feedback!  Definitely a positive consensus
about the units for start_offset ;-)

Jasmine suggests that I should leave some extra after the end of grub for
future expansion, which seems a good idea, but raises in my mind the
question as to how grub (or anything else) knows where the nftl partition
starts?  Does nftl_format also write a pointer to the start block
somewhere else?  Or does the format contain some kind of signature?

Re the suggestions as to how to recover from an unbootable system!  To
an old fool like me, the idea of pushing a chip into a live board makes my
hair curl!  Anyways, I hope it doesn't come to that as it would in my case
be extremely difficult, if not impossible - I'm using an SBC plugged into
a passive backplane and the DoC socket is right at the bottom next to the
edge connector ;-(

Jasmine also comments that:

> > and cdrom.  So if I screw up this nftl_format and trash grub, I'm
> > going to end up with an unbootable system ;-(
> 
> no you aren't.  If you tell grub:
> 
> rootnoverify (fd0)
> chainloader +1
> boot
> 
> it will boot off the floppy.

But this assumes that I *haven't* trashed grub?

> (If you totally trash grub, the BIOS won't load
> anything off the DoC in the first place.)

Can it take that to mean that the BIOS will do some kind of checksum on
the code it's going to pass control to (i.e., in this case, grub) and
*won't* jump to it if the checksum fails?  That would be nice but I fear
it's not the case given the advice from the other guys who have obviously
on occasion found themselves in exactly this kind of mess?

And finally, off-list (so to speak) I've had this email from Cfowler
<cfowler@outpostsentinel.com>:

> Do not use grub.  You have erased the badblock table on that DOC and it
> is no logner good for production.  I spent 2 days recovering from this
> mess.

What am I to make of that?

TIA
John

On Wed, 01 May 2002, you wrote:
> > or nftl_format /dev/mtd0 98304  (bytes)
> 
> this one is correct
> 
> > 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!
> 
> *** WARNING *** WARNING *** WARNING *** WARNING ***
> 
> THIS CAN DAMAGE YOUR HARDWARE AND BLOW YOU UP
> (but it seems to work for me)
> 
> *** WARNING *** WARNING *** WARNING *** WARNING ***
> 
> I have an ISA card for the DOC2000, I boot up my workstation, carefully
> plug in the isacard, modprobe doc2000, insmod docprobe insmod mtdchar
> (if necessary) insmod nftl (if necessary). Do whatever I need to do,
> rmmod nftl, rmmod docprobe, rmmod doc2000, and remove the card. On my
> machine, doing this using the devfsd nodes causes an oops after the
> first time, a simple workaround is using hand made device files.
> 
> *** WARNING *** WARNING *** WARNING *** WARNING ***
> 
> THIS CAN DAMAGE YOUR HARDWARE AND BLOW YOU UP
> (but it seems to work for me)
> 
> *** WARNING *** WARNING *** WARNING *** WARNING ***
-- 

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

Re: Booting from DOC2000 with GRUB loader

[Russ Dill]

On Thu, 2002-05-02 at 00:47, John Sutton wrote:
> Hi again
> 
> Many thanks for all that feedback!  Definitely a positive consensus
> about the units for start_offset ;-)
> 
> Jasmine suggests that I should leave some extra after the end of grub for
> future expansion, which seems a good idea, but raises in my mind the
> question as to how grub (or anything else) knows where the nftl partition
> starts?  Does nftl_format also write a pointer to the start block
> somewhere else?  Or does the format contain some kind of signature?

just sure to erase any unused sectors.


nftl looks for a media header signiture

> Re the suggestions as to how to recover from an unbootable system!  To
> an old fool like me, the idea of pushing a chip into a live board makes my
> hair curl!  Anyways, I hope it doesn't come to that as it would in my case
> be extremely difficult, if not impossible - I'm using an SBC plugged into
> a passive backplane and the DoC socket is right at the bottom next to the
> edge connector ;-(

maybe something in bios could help (shadow regions, etc)

Re: Booting from DOC2000 with GRUB loader

[John Sutton]

Nearly there ;-)...

On Thu, 02 May 2002, Russ Dill wrote:
> On Thu, 2002-05-02 at 00:47, John Sutton wrote:
> > Hi again
> > 
> > Many thanks for all that feedback!  Definitely a positive consensus
> > about the units for start_offset ;-)
> > 
> > Jasmine suggests that I should leave some extra after the end of grub for
> > future expansion, which seems a good idea, but raises in my mind the
> > question as to how grub (or anything else) knows where the nftl partition
> > starts?  Does nftl_format also write a pointer to the start block
> > somewhere else?  Or does the format contain some kind of signature?
> 
> just sure to erase any unused sectors.

Is a sector a block?  And what is a block?

Here's where I'm up to now:

./nftl_format /dev/mtd0 98304
$Id: nftl_format.c,v 1.17 2001/08/29 14:28:48 dwmw2 Exp $
Erase size not 8Kb - I'm confused

So I put a %d for meminfo.erasesize in the printf and I get:

./nftl_format /dev/mtd0 98304
$Id: nftl_format.c,v 1.17 2001/08/29 14:28:48 dwmw2 Exp $
Erase size not 8Kb - I'm confused 16384

So I've got a 16Kb erase size.  What now?  If I hack the source so that it
just falls through this test and proceeds to malloc(meminfo.erasesize * 5)
am I heading for big trouble or success?

Once I've gotten past this little gotcha, how do I go about using the
erase util to erase the piece between the end of the grub and the start of
the nftl partition?  I'm thinking that if I start the nftl at 98304 then I
don't need to erase anything because doc_loadbios will have already erased
the unoccupied 96k-87k=9k at the end of the last of the 6 blocks. 
Whereas, if I do:

./nftl_format /dev/mtd0 114688  ( i.e. 7 x 16k block )

then I'll need to do:

erase /dev/mtd0 6 1

or, should that be:

erase /dev/mtd0 98304 16384

Sorry to be a dummy ;-(

Thanks again!

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

Re: Booting from DOC2000 with GRUB loader

[Ilguiz Latypov]

John,

On Thu, 2 May 2002, John Sutton wrote:

> Erase size not 8Kb - I'm confused

Do I understand correctly from the numerous clarifications in this mailing
list that the nftl_format utility may result in an NFTL layer incompatible
with the M-System's one when the chip's erase size is not 8Kb?  I myself 
removed the check and was able to format and use the chip.

I am dumber when it comes to the bad block table issue.  My guess is that
nftl_format marks bad erase sectors in the NFTL bad block table.  No way
GRUB itself is aware of any bad sectors in its own area.  My impression is
that erase sectors can be marked as bad in their ECC header, but others
may give you a less idiotic answer.

Ilguiz

Re: Booting from DOC2000 with GRUB loader

[Jasmine Strong]

On Thursday, May 2, 2002, at 05:09 PM, Ilguiz Latypov wrote:
> I am dumber when it comes to the bad block table issue.  My guess is 
> that
> nftl_format marks bad erase sectors in the NFTL bad block table.

It's supposed to but David wasn't sure whether this code worked properly.
Regardless of that, the blocks have their good/bad status marked in the
OOB area and nftl_format, while it doesn't necessarily handle it 
correctly,
certainly doesn't destroy that data.

>   No way
> GRUB itself is aware of any bad sectors in its own area.

If that area was bad, the chip would most likely be unusable-  the IPL
code isn't smart enough to take notice of such things, so any chips that
had badness in the first 48k or so would have failed M-Systems factory
QC.

Jas.

Re: Booting from DOC2000 with GRUB loader

[Jasmine Strong]

On Thursday, May 2, 2002, at 11:56 AM, John Sutton wrote:

> Nearly there ;-)...
>

Indeed so :-)

> So I've got a 16Kb erase size.  What now?  If I hack the source so that 
> it
> just falls through this test and proceeds to malloc(meminfo.erasesize * 
> 5)
> am I heading for big trouble or success?

I *think* it works.

> Once I've gotten past this little gotcha, how do I go about using the
> erase util to erase the piece between the end of the grub and the start 
> of
> the nftl partition?

Why not just erase the entire thing, then do doc_loadbios to put the 
grub firmware into it, and then nftl_format?  Then you'd be sure it was 
all
clean and empty.

That's how I did it, anyway.

Jas.

Re: Booting from DOC2000 with GRUB loader

[Frederick Lefebvre]

I have some poblem getting grub+doc working.

I followed the instructions :

1- patched grub-0.91 with mtd/patches/grub-2002-02-19-doc.patch
2- ./configure --enable-diskonchip-2000
3- make
4- cp stage2/pre_stage2 mtd/grub
5- cd mtd/grub
6- make
7- ../util/doc_loadbios /dev/mtd0 grub_firmware
8- reboot (I have a nftl partition right after the grub on the doc 2000)

I get the grub prompt but it does not know about dc0.  When I enter
"root (dc0,0)", I get : "Error 21: Selected disk does not exist".

Did I do something wrong?

Fred

Re: Booting from DOC2000 with GRUB loader

[Ilguiz Latypov]

Frederick,

There can be 2 things missing: 

  a) the *.in files must be re-generated with 

         aclocal && automake && autoconf

     as John Sutton showed in the RPM spec file.  Also, there is 
     README_DiskOnChip file in the patch that advises the same.

  b) The only block device layer supported by the DoC MTD patch to GRUB is 
     NFTL.  This means you may need to create a filesystem on top of the 
     /dev/nftla device or partition it into pieces with fdisk.  In the 
     first case you may need to specify "root (dc0)".

If you don't want to mess with NFTL layer, you might be interested in
another bootloader based on FFS2 filesystem.  I saw it in the boot
directory of the MTD CVS repository, but never tried it.

Perhaps, the GRUB bootloader can be modified to access a read-only
filesystem created on top of the raw NAND flash sectors.

And finally, the read-write JFFS2 filesystem was specifically designed
with flash memory in mind.  I heard about experimental work to enable
JFFS2 on NAND flash chips.  See the mailing list archives.  It would be
nice to make GRUB recognize JFFS2 filesystem.

Ilguiz

On 2 May 2002, Frederick Lefebvre wrote:

> "root (dc0,0)", I get : "Error 21: Selected disk does not exist".

Re: Booting from DOC2000 with GRUB loader

[John Sutton]

Ah, sweet success!

After a number of you made clear that you'd already blazed this trail, I
took the plunge and commented out the "I'm confused" check in nftl_format,
and ran it:

[root@spartam util]# ./nftl_format /dev/mtd0 98304
$Id: nftl_format.c,v 1.17 2001/08/29 14:28:48 dwmw2 Exp $
Phase 1. Checking and erasing Erase Zones from 0x00018000 to 0x01000000
Skipping bad zone (factory marked) #672 @ 0xa80000
        Checking Zone #1023 @ 0xffc000
Phase 2.a Writing NFTL Media Header and Bad Unit Table
Phase 2.b Writing Spare NFTL Media Header and Spare Bad Unit Table
Phase 3. Writing Unit Control Information to each Erase Unit

All looks good to me, and the stuff about skipping factory marked zones
and writing bad unit tables certainly give the impression that it knows
what it's doing!  So my previous concern re "You have erased the badblock
table on that DOC and it is no logner good for production" was probably
misplaced?  Anyway, in my application, once I've put this thing to bed, I
only expect to have to rewrite a small part of the doc, and only that say
half a dozen times in the lifetime of the system.  So with an expected
minimum rewrites of 100,000 (according to M-systems web site), I'm surely
in the clear.

After that I fdisked /dev/nftla and set up partitions, mke2fs, mkdir
/boot, put a kernel in it, mkdir /boot/grub and put a menu.lst in there,
reboot, bingo!

I realise with the benefit of hindsight that to avoid the danger of ending
up with an unbootable system when doing the nftl_format, all that's
necessary is to always follow it with (another) doc_loadbios.  So, even if
you can't figure out the numbers exactly, you'll get there eventually by
trial and error.

Some outstanding oddities with my grub on DoC:

1) At the command line (at least) the backspace key seems to have gotten
munged?  It seems to be emitting a single ^H rather than ^H<space>^H so
it's not clear that you've actually deleted a character (but you have). 
Maybe this is the same with vanilla grub (i.e. without mtd patch) but I
didn't notice it before?

2) More disconcerting, the TAB completion of valid devices in the "root"
command does not wholly recognise the "dc" prefix.  The behaviour, which
is rather complex, is as follows:

root (      hit TAB sees only my scsi disks hd0 and hd1
root (d
root (dc    hit TAB both give errors
root (dc0   hit TAB its happy with but it doesn't give you the comma
root (dc0,  hit TAB now its motoring!  It's shows me my 2 partitions 0 and
1 and, once I've selected one, TAB completion of filenames in the
partition when using the "kernel" command works fine.

Maybe both of these problems arise from the fact that I applied the latest
mtd patch (grub-2002-02-19-doc.patch) against a *later* grub source
(0.92)?  A few of the hunks were "shifted" (applied at different line
numbers) but they did stick.

Here are a few observations on the whole process which haven't come up
(explicitly at least) in this thread so far and which might be of help to
others:

1)  I've you've already gotten lilo going on your doc and are now trying
to get grub going, note the crucial difference: when you put grub on
the doc as opposed to putting it on a floppy or hard disk, you are putting
both stage1 AND stage2 on there.  Which is nice once you've understood
that ;-)  But if (like me) you thought you were just putting a 512 byte
boot loader on the grub which then knows the address of an mtd-aware
stage2 stored in an nftl partition, then it comes as a rather rude surprise
to find that you've trashed your existing efforts.

2)  Related to 1 (and here I'm only clear about the generalities and not
the details), note that the nftl format which exists on the doc when you
take it out of the wrapper - which is put on there by M-systems - is not
the same thing as that which you end up with (and need) to use grub. 
Quite why we've got 2 different implementations of this format on the go, I
don't know, but I became aware of it rather painfully ;-).

I started with the 2.4.18 kernel sources and using the help in make
menuconfig put together a kernel which looked like it would do the job. 
And it did, so far as it went - on booting the kernel I could see the
chip, fdisk /dev/nftla, mke2fs, everything sorted.  But then (no big
surprise) I found that vanilla lilo couldn't deal with it, so I downloaded
M-systems patched lilo, installed that and everything looked good.  The
point here however is that up to this point I am still using the nftl
format put on there by M-systems.  Once you want to have a go with grub,
this is no good.  (Presumably precisely because the mtd-patched grub
insists on putting stage2 onto the doc thus trashing this existing format?
 Can't see why you couldn't have a "standard" grub installation which
would only need to overwrite 512 bytes like lilo does?  Not that that
would have much merit in itself.)

Anyway, upshot of all this is that the kernel I'd built (and which I'd
imagined was everything needed because this far it had done everything
required of it) was no good because I'd omitted CONFIG_MTD_CHAR.  So when I
tried doc_loadbios /dev/mtd0 it wouldn't work because there was nothing
listening. (Cannot open device, or something like that.)  After some
digging about in the kernel sources, I realised what was missing, built a
new kernel, ran doc_loadbios and THEN, when I saw it erasing 96k instead
of 512 bytes, the penny finally dropped!

Here are the kernel config options which I've ended up with for my DoC2000
chip (and with everything paranoid switched on ;-) :

CONFIG_MTD=m
CONFIG_MTD_CHAR=m
CONFIG_NFTL=m
CONFIG_NFTL_RW=y

CONFIG_MTD_DOC2000=m
CONFIG_MTD_DOCPROBE=m
CONFIG_MTD_DOCPROBE_ADDRESS=0

CONFIG_MTD_NAND=m
CONFIG_MTD_NAND_ECC=y
CONFIG_MTD_NAND_VERIFY_WRITE=y

I started off with all this built in the kernel rather than as modules but
was getting fed up with docprobe (CONFIG_MTD_DOCPROBE) making a mess of my
console and syslog.  And on reading docprobe.c turns out that this probing
process is sometimes dangerous as well as messy, so I changed to building
as modules because then you can pass a single address in modules.conf:

options docprobe doc_config_location=0xcc000

Of course, YMMV in respect of the particular address at which your chip
presents itself.  (Mine is set with jumpers on the motherboard).  No doubt
this will end up being available as a kernel parameter in due course but
as best I can tell it has to be a module option at present.

So, happy grubbing and many thanks to all.  Hopefully I'll get this damn
thing out of the door pretty soon and will not be bugging you guys any
longer, but I'd be pleased to give assistance to any newbies out there. 
But note, I'm not subscribed to the list so be sure to copy any post to me
john@scl.co.uk if you think I can help you.

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

Re: Booting from DOC2000 with GRUB loader

[Jasmine Strong]

On Friday, May 3, 2002, at 02:40 PM, John Sutton wrote:
> ...the nftl
> format put on there by M-systems.  Once you want to have a go with grub,
> this is no good.  (Presumably precisely because the mtd-patched grub
> insists on putting stage2 onto the doc thus trashing this existing 
> format?

Yes.  The M-systems stuff reserves a block at the start of the DoC for
the BIOS extender-  however it only seems to be 48kbytes on any of the
parts I've tried, so that's not big enough for grub, and you need to
make more space.

If you don't reformat and make more space, you'll trash the first two
blocks of the NFTL, which contain the media headers, and this will
effectively destroy the NFTL.

>  Can't see why you couldn't have a "standard" grub installation which
> would only need to overwrite 512 bytes like lilo does?  Not that that
> would have much merit in itself.)

You could, but you would have to leave the M-Systems int13h 
implementation
in the first 48k of the DoC (as an unpatched grub would need to be able 
to
use standard int13h calls to read its second stage) and that would suck
*much* harder than just reformatting the thing.

Jas.

Booting from DOC2000 with GRUB loader

[Zhiwei Yu]

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.

-Zhiwei

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Re: Booting from DOC2000 with GRUB loader

[Russ Dill]

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.