[olpc-help] Making image of onboard flash for restore purposes

[Richard A. Smith]

Denver Gingerich wrote:

> I understand from the wiki that the G1G1 laptops have firmware
> security enabled by default so I will not be able to boot an external
> device unless I get a developer key.  Is that correct?  Can I get a
> developer key without booting the laptop?

Not quite.  OFW uses a file called 'olpc.fth' to decide where to load
the kernel from.  Its located in /versions/boot/current/boot modifying
this file you are free to load a kernel from any device that
openfirmware supports which includes SD,USB, and Network.

What you can't do is boot a kernel that is not signed.  So if you take
the kernel + initrd thats on the nand and copy it to an eternal device
and then modifiy olpc.fth to use that device and pass in the right root
device it should work.  Its been done.  Its not something that we test
on a regular basis so there may be a few bumps in the road.

> It seems like doing a backup of the flash might be a bit of a hassle
> given the firmware security.  Is it even worth it to try making a copy
> of the flash?  Or can I get an image of the factory default flash
> contents from somewhere else in case I need to restore?

Yes. There are complete signed jffs2 images on xs-dev.  See the
upgrading wiki pages for details.

-- 
Richard Smith  <richard at laptop.org>
One Laptop Per Child