[U-Boot-Users] using a flat device tree to drive u-boot config

Jens Gehrlein sew_s at tqs.de
Mon Aug 4 09:16:47 CEST 2008


Grant Likely schrieb:
> On Sun, Aug 3, 2008 at 11:49 AM, Timur Tabi <timur at freescale.com> wrote:
>> On Sun, Aug 3, 2008 at 10:47 AM, Wolfgang Denk <wd at denx.de> wrote:
>>
>>> If the  DTB  can  be  at  any
>>> flash location, you can for example have a fall-back version which is
>>> used  to bring up U-Boot in a minimal configuration for recovery mode
>>> if the new DTB fails to work.
>> I think that a "recovery DTB" would have to be part of U-Boot itself
>> to be effective.  If the normal DTB is not available, then it's likely
>> the backup one would also be unavailable.
> 
> Better to just not depend on the DTB at all for basic operation.  ie.
> don't brick the board if the DTB is unavailable.

If the DTB is not available or invalid, the settings in the config 
header file could be used as default values. At least, U-Boot should 
start with a limited function volume to be able to load valid DTB.

It's also possible to have no DTB at all for platforms not (or not yet) 
supporting the flat device tree.

Kind regards,
Jens




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