Bootloader question

Guylhem Aznar olpc at guylhem.net
Tue Jun 2 23:43:02 EDT 2009


Hello,

On Tue, Jun 2, 2009 at 22:12, Mitch Bradley <wmb at laptop.org> wrote:
> Don't believe everything you read on a wiki.
> OFW has included support for partitioned NAND since the first production
> shipments, dating back to January 2008.  The idea is to have a small
> boot partition that can be in any format that OFW supports - JFFS2,
> ext2, FAT, or even a .zip archive.  JFFS2 is just fine on a small
> partition; the scan time for a few MB is negligeable. I have been
> lobbying for such a structure for about 2 years now, but never managed
> to get enough traction among the OS people to actually implement it in
> the XO software distribution.  The OFW support for this is known to
> work, as debxo uses it.

I'm sorry, I didn't know that and I didn't want to imply OFW was not
the right tool for the job.

I'm just very concerned by the current time it takes for a vanilla
olpc to be ready, especially when compared to any netbook running
moblin, so I'm exploring various ways to fix the problem (actually
rereading every documentation that was send to me explaining various
aspect of the OFW before starting the UBIFS tests, but I have limited
time and I'd like to spend in on the UI rather than  on the boot
process)

What would you suggest to have the kernel loaded in ram as quickly as
possible? (I'd guess execute in place, but I think that's not
possible) A fat partition with the zimage ?

I'd also like to remove the initrd to try to shave some seconds. I
don't need any antitheft protection, I just want to protect the nand
against a reflash with a non approved software image, which IMHO is
the most interesting feature of OFW. But if that's too
complicated/requires the initrd or some weird other stuff, I'll scrap
that too.

BTW, could you point me to some documentation explaining how to have
OFW immediately boot a kernel, without fancy sound/screen/counter?
(only prioritising USB or MMC, so that it boots first if a media is
inserted or if a struck "esc" key is detected it gives a command
prompt)

I'm open to any additional suggestions. (I'll consider the sysvinit
optimisations later)


Thanks
-- 
Dr. Guylhem Aznar, MD PhD

Unité d'Analyse Médico-Économique
Service de Santé Publique et d'Économie de la Santé
Pôle SPSSR
CHU de Fort de France
BP 632
97261 Fort De France Cedex
Martinique, France

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