[maemo-users] [maemo-users] Booting from MMC as a de-bricking method

From: Frantisek Dufka dufkaf at seznam.cz
Date: Tue Feb 13 16:07:50 EET 2007
Paule Ecimovic wrote:
> Hi, all
>    Is it possible to boot from MMC (assuming one sets up this booting 
> option by cloning the 770 on a suitably-large MMC and installing the 
> alternate boot loader and all the rest) to recover from a bricking 
> flash?

Boot from mmc can help you only when the problem is in rootfs partition 
i.e. (a bit simplistic explanation) when booting the device blue 
progressbar on the bottom starts.

I'm not sure what you mean by 'bricking flash' but any device reflash 
with full firmware image removes modified initfs with boot menu and then 
you cannot boot from mmc at all (without reflashing modified initfs 
back). But this is not big problem because booting from mmc allows you 
to stop fixing problems with your device by reflashing. Instead of 
reflashing you can boot clean system and either mount broken system and 
fix it (if you know how) or save data from it and clone your clean 
system to mmc and start again.

> Are there bricking scenarios from which it is not possible to 
> recover via booting from MMC?

Definitely yes but most things that can normally go wrong happen in 
rootfs. Examples:

- you install bad/incompatible package
- you try apt-get upgrade
- you are trying to hack startup sequence
- device reboots in wrong moment and some system files get lost or 
become corrupted (yes this really happens sometimes if you are unlucky)


More information about the maemo-users mailing list