Boot from DoC2000

Boot from DoC2000

[Darren Martz]

I'm new to linux, so my questions may seem rather simplistic <g>

Sorry for the multiple questions, I have read most of the papers and
many of the posting on this list but these are missing pieces...

It seems the m-sys driver adds logic to the bios gaining access to the
DoC. The mtd solution everyone is working so hard on seems to do things
differently, but I'm not sure how or what.  I am also unclear as to what
boot loaders support this new way to boot an mtd device. I understand
grub is designed to support that scenario but is still in development.
Does the lilo solution rely on the m-sys patch?

I suppose a boot loader like grub is required because the bios doesn't
support native access to the device(s).

So what filesystem options are there? I know that m-sys has their own
"TrueFFS" fs, and it requires a kernel patch. Being new to linux, I'd
like to stay away from that for the time being. I have read about jffs1
and jffs2, and from what I can tell jffs1 is stable but lacking the nice
features, while jffs2 is very much experimental but coming along nicely.

Knowing all that, the options seem to be as follows:

1) LILO plus an m-sys patch with the TrueFFS or any other filesystem
2) GRUB with any filesystem including JFFS, but not TrueFFS
3) SYSLINUX ??? i suspect is not supported

I believe I read that to date, nobody has had a successful boot on a DoC
with grub - yet! 
So does that leave the only current option as LILO with the m-sys patch?

Darren

Re: Boot from DoC2000

[Russ Dill]

On Thu, 2002-05-09 at 02:40, Darren Martz wrote:
> I'm new to linux, so my questions may seem rather simplistic <g>
> 
> Sorry for the multiple questions, I have read most of the papers and
> many of the posting on this list but these are missing pieces...
> 
> It seems the m-sys driver adds logic to the bios gaining access to the
> DoC. The mtd solution everyone is working so hard on seems to do things
> differently, but I'm not sure how or what.  I am also unclear as to what
> boot loaders support this new way to boot an mtd device. I understand
> grub is designed to support that scenario but is still in development.
> Does the lilo solution rely on the m-sys patch?
> 
> I suppose a boot loader like grub is required because the bios doesn't
> support native access to the device(s).
> 
> So what filesystem options are there? I know that m-sys has their own
> "TrueFFS" fs, and it requires a kernel patch. Being new to linux, I'd
> like to stay away from that for the time being. I have read about jffs1
> and jffs2, and from what I can tell jffs1 is stable but lacking the nice
> features, while jffs2 is very much experimental but coming along nicely.
> 
> Knowing all that, the options seem to be as follows:
> 
> 1) LILO plus an m-sys patch with the TrueFFS or any other filesystem
> 2) GRUB with any filesystem including JFFS, but not TrueFFS
> 3) SYSLINUX ??? i suspect is not supported
> 
> I believe I read that to date, nobody has had a successful boot on a DoC
> with grub - yet! 
> So does that leave the only current option as LILO with the m-sys patch?

look at the mailing list archives, grub works great on a DOC. jffs2 (or
jffs) is not ready for use on a DOC, but its close, so you'd have to use
a standard filesystem on top of NFTL.

actually, syslinux works fine with the original m-sys "firmware"

RE: Boot from DoC2000

[Darren Martz]

Russ,

Thanks for the clarification, I didn't realize that JFFS/2 was the only
unstable part. Being new to this, I'm trying to stick to as few patches
as possible. I'll look into grub with nftl.

Darren

> look at the mailing list archives, grub works great on a DOC. jffs2
(or
> jffs) is not ready for use on a DOC, but its close, so you'd have to
use a standard filesystem on top of NFTL.

> actually, syslinux works fine with the original m-sys "firmware"

Re: Boot from DoC2000

[Thomas Gleixner]

On Thursday, 9. May 2002 19:06, Darren Martz wrote:
> Russ,
>
> Thanks for the clarification, I didn't realize that JFFS/2 was the only
> unstable part. Being new to this, I'm trying to stick to as few patches
> as possible. I'll look into grub with nftl.
For further clarification, JFFS2 is not unstable. There's just no support for 
DOC. :)
-- 
Thomas
___________________________________
autronix automation GmbH
http://www.autronix.de gleixner@autronix.de

Re: Boot from DoC2000

[David Woodhouse]

You're a little confused. There are two options for the physical format on 
the DiskOnChip. First, there's 'NFTL', which is what M-Systems refer to as 
'TrueFFS', which emulates a block device. On top of that block device you 
put a normal filesystem -- VFAT, ext2 or whatever you prefer.

You need support for that in two places - both in your bootloader which has 
to load the kernel off it, and in your kernel which has to actually _use_ 
it. Just to add to the confusion, for _each_ of those requirements you have 
a choice of two methods.

The kernel part is simple - either you use their binary-only module with an 
initrd hack to get it loaded, or you use the GPL'd support for NFTL which 
is included in the official 2.4 kernel tree.

The bootloader part is only slightly less simple. The DiskOnChip ships with 
firmware built-in that hooks into the INT 13h disk BIOS interrupt, to make 
it look like a normal hard disk driver to DOS and LILO. If you want, you 
can replace their firmware with Grub. To make that useful, you have to have 
a copy of Grub which is capable of reading the DiskOnChip directly, as 
you're going to have taken away the INT 13h support.

Alternatively, you can use JFFS2 on the DiskOnChip. You need to fix up the 
DiskOnChip hardware drivers a little to handle reads and writes larger than 
512 bytes; nothing else that I recall. Booting a kernel on a JFFS2 file 
system on DiskOnChip is not yet implemented. I'd be inclined to use RedBoot 
for that.

--
dwmw2

RE: Boot from DoC2000

[Darren Martz]

That makes much more sense, you explained it very well - thanks David!

I'm going to push on with grub using the NFTL and ext2.

My PC/104 board has an older/patched version of lilo and linux on it,
how do I replace the current lilo firmware? I have already formatted the
device from a floppy boot (may that wasn't so smart). Can I install grub
over top of the existing lilo by bootdisk, or do I need to uninstall
lilo first?

So far I have downloaded grub 0.92, ran "configure" and "make" on my
desktop-pc. I put the stage1 and stage2 files using dd, as the manual
indicates, on a floppy and successfully booted the PC/104 board... but I
am having troubles figuring out how to access the DoC or to install grub
on the device. Is there a document that covers most/part of this? I am
assuming the 0.92 build has DoC support.

Darren

-----Original Message-----
From: linux-mtd-admin@lists.infradead.org
[mailto:linux-mtd-admin@lists.infradead.org] On Behalf Of David
Woodhouse

You're a little confused. There are two options for the physical format
on 
the DiskOnChip. First, there's 'NFTL', which is what M-Systems refer to
as 
'TrueFFS', which emulates a block device. On top of that block device
you 
put a normal filesystem -- VFAT, ext2 or whatever you prefer.

You need support for that in two places - both in your bootloader which
has 
to load the kernel off it, and in your kernel which has to actually
_use_ 
it. Just to add to the confusion, for _each_ of those requirements you
have 
a choice of two methods.

The kernel part is simple - either you use their binary-only module with
an 
initrd hack to get it loaded, or you use the GPL'd support for NFTL
which 
is included in the official 2.4 kernel tree.

The bootloader part is only slightly less simple. The DiskOnChip ships
with 
firmware built-in that hooks into the INT 13h disk BIOS interrupt, to
make 
it look like a normal hard disk driver to DOS and LILO. If you want, you

can replace their firmware with Grub. To make that useful, you have to
have 
a copy of Grub which is capable of reading the DiskOnChip directly, as 
you're going to have taken away the INT 13h support.

Alternatively, you can use JFFS2 on the DiskOnChip. You need to fix up
the 
DiskOnChip hardware drivers a little to handle reads and writes larger
than 
512 bytes; nothing else that I recall. Booting a kernel on a JFFS2 file 
system on DiskOnChip is not yet implemented. I'd be inclined to use
RedBoot 
for that.

--
dwmw2

Re: Boot from DoC2000

[David Woodhouse]

dmartz@shelbrook.com said:
>  My PC/104 board has an older/patched version of lilo and linux on it,
> how do I replace the current lilo firmware? I have already formatted
> the device from a floppy boot (may that wasn't so smart). Can I
> install grub over top of the existing lilo by bootdisk, or do I need
> to uninstall lilo first? 

Grub (or the original firmware) live in the raw flash, before the actual NFL
format starts. Grub is bigger than the original firmware, so when you 
install Grub, you have to recreate the NFTL format. It's best to do this 
with the M-Systems DFORMAT program under DOS, but it's also possible to use 
the Linux nftl_format program which doesn't deal with bad blocks properly.

You can tell the DFORMAT program how much space to reserve for the 
firmware, I believe. 

You need to apply the DiskOnChip patches to Grub, if they're not already 
merged. 

--
dwmw2

RE: Boot from DoC2000

[Ilguiz Latypov]

Darren,

On Thu, 9 May 2002, Darren Martz wrote:

> Is there a document that covers most/part of this? I am assuming the
> 0.92 build has DoC support.

There is a patch to GRUB enabling DoC read support.  The latest one is

       patches/grub-2002-02-19-doc.patch

in MTD CVS repository.  One has to apply it with the following command:

        cd ~/grub
        patch -p0 -i ~/infradead.org/mtd/patches/grub-2002-02-19-doc.patch

You can experience inconsistencies between the patch and the latest GRUB 
Changelog.

Once you patched the GRUB source code, take a look at README_DiskOnChip 
for further configuration commands.  You may be required to update 
autoconf and automake.

Ilguiz

Re: Boot from DoC2000

[David Woodhouse]

dmartz@shelbrook.com said:
> I have read about jffs1 and jffs2, and from what I can tell jffs1 is
> stable but lacking the nice features, while jffs2 is very much
> experimental but coming along nicely.

Forgot to respond to this bit earlier...

JFFS2 on NAND is experimental. JFFS2 on NOR is stable; more so than JFFS1 
now, I think.

--
dwmw2