[U-Boot] [PATCH v3] AT91SAM9*: Change kernel address in dataflash to match u-boot's size

[Alexandre Belloni]

On Wed, Feb 29, 2012 at 01:50:18AM +0100, Ulf Samuelsson wrote :
> > 
> >> 2. Std AT91bootstrap loads U-Boot from 0x8400
> >>    so your patch breaks 99% of all SAM9  boards.
> >> 
> > 
> > Those boards are broken anyway !
> 
> No they are not.
> The partitioning gives you some hint on where to store the kernel,
> but you can store the kernel at any suitable address.
> you lose some conveniance, but thats all.
> 
> Storing U-boot at any other address than 0x8400, means that AT91bootstrap
> must be modified, and there is significant disadvantages in having two possible u-boot locations.
> if you have an at91bootstrap binary, will this use the old or new location?
> I fail to see any benefit in moving, so that 
> 
> 
> 
> > As u-boot is bigger than the load size
> > of at91bootstrap (0x33900 by default). So, not changing means that you
> > are screwed after flashing a new u-boot
> 
> IIRC, The latest bootstrap with Kconfig has configurable size.
> Changing size is OK, changing location is not.
> 
> 

Doesn't that mean that you then have to recompile/reflash at91bootstrap
and so that the boards are broken using the latest ut-boot ? I couldn't
get my board working with the stock at91bootstrap because it cannot load
u-boot.

It has to be fixed or I don't see the point in keeping those configs.
If we don't want to change the location, and I can understand the
reasons why, then was my first patch ok ?

http://lists.denx.de/pipermail/u-boot/2012-January/114485.html

I'd like to see that fixed so that I could integrate it properly in
buildroot...

> 
> 
> >> If you want to grow U-Boot, then
> >> 
> >> bootstrap  0x00000000        ; 16 kB
> >> ubootenv   0x00004200        ; 16 kB    - Should be plenty
> >> uboot      0x00008400        ;
> >> kernel     0x00063000        ; Why waste space...
> >> 
> > 
> > What about the redundant env ? Why shouldn't we reorder u-boot and its
> > env ?
> 
> Because it adds problems without any benefits.
> When I looked the last time, the environment is only 8 pages,
> So you can fit a redundant environment anyway in 16 kB+}
> 



-- 
Alexandre Belloni