Re: [Qemu-devel] [patch 1/2] Add Flash support to the Versatile PB platform

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hi Cédric !

Le Mon, 13 Oct 2008 22:35:54 +0200,
"Cedric Hombourger" <chombourger@gmail.com> a écrit :

> Well done! I have had a modified qemu for sometime now to do this as
> well but never got to the point where the Linux kernel could mount the
> root file-system from flash. I quickly gave a try to your patch using
> the latest svn and it seems to be the same (i.e. u-boot ok, kernel
> gets loaded from flash to memory and then boots but it fails to mount
> a root file-system). I have started to look into this but not yet deep
> enough to understand what is going on.... my kernel seems to be
> reading zeros instead of the cramfs magic number while the address
> that I am reading from seems to be correct. Is this something that you
> have tested and works for you? I will be happy to help if you also
> have issues.

So far, I've only tested :

 * Starting U-Boot from the Flash ;
 * Loading the kernel to RAM from TFTP in U-Boot ;
 * Saving the kernel to Flash ;
 * Saving the U-Boot environment to Flash ;
 * Booting the kernel from Flash ;
 * Having the kernel detect the Flash partitions ;
 * Erase one block of Flash from Linux using flash_erase.

I haven't tested yet mounting root filesystems from Flash, so it's
possible that it doesn't work completely. I'll try to have a look at
this during this week.

Thanks for testing and thanks for your feedback !

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.
http://free-electrons.com