[U-Boot-Users] dtb in env sector - was: (Try 2) Please pull ...

[Jerry Van Baren <gerald.vanbaren@smiths-aerospace.com>]

Joakim Tjernlund wrote:
> On Tue, 2007-04-03 at 14:59 +0200, Wolfgang Denk wrote:
>> In message <1175600261.12080.24.camel@gentoo-jocke.transmode.se> you wrote:
>>> I think to start with one would just need an install dtb command that
>>> places the dtb at the end of the env. sector to allow either one
>>> to grow without trashing eachother. Also rendundant env needs to be
>> Umm... The environment will not grow beyond it's defined  size.  Then
>> just use "cp" to copy the dtb to the next free address.
> 
> And later you need some more space for env. so you increase CFG_ENV_SIZE
> a little and now you have destroyed your dtb as well.

Actually, it is much worse than that: currently when you do a "saveenv" 
it will wipe out the fdt blob because it doesn't know that the blob is 
in the same sector.

I'm thinking that we want to store the blob immediately after the env 
variable storage _reserved area_ as a #define option (as a new #define 
option? part of the CONFIG_OF_LIBFDT define?) and enhance the env 
save/restore to do the blob too.  This would get us the redundancy and 
we can cover it with a new (preferred?) or existing env CRC (not good?).

>>> Secondly one needs someway of telling bootm where to find the dtb.
>> You pass the address as an argument...
> 
> yes, but it would be handy to just say "use the dtb in my spare
> env space", especially if you use rendundant env. so the right
> one is selected.
> 
>  Regards
>           Jocke

Best regards,
gvb