[U-Boot-Users] heap location (PXA)

[Robert Schwebel]

On Mon, Jul 28, 2003 at 10:24:53AM +0200, Nemec, Bernhard wrote:
> I'm porting u-boot 0.4.0 to a custom PXA255 board similar to the CSB226, of
> which I used the configuration as a starting point.
> 
> What I'm confused about ATM is _armboot_real_end, which is used for heap
> initialisation with mem_malloc_init() in lib_arm/board.c.
> 
> 1 - _armboot_real_end has the value 0x0BADC0DE, which is not in RAM, but in
> FLASH range of the PXA.
> 
> 2 - the heap is supposed to be located *below* u-boot, not above, since
> u-boot itself gets relocated to the upper end of RAM.
> 
> Therefore I would propose to change
> 
>       mem_malloc_init (_armboot_real_end);
> to
>       mem_malloc_init ( _armboot_start - CFG_MALLOC_LEN );
> 
> in start_armboot().
> 
> I'm interested in any thoughts on the subject.

I've noticed that as well when I started porting u-boot to some PXA
boards. My -ptx patches (see www.pengutronix.de) contain a fix to for
the memory layout but Wolfgang has rejected the patch until the whole
mess of the different initialisation strategies between ARM and PPC is
resolved. As I didn't have time to do some work in this area yet things
are still the way they are...

Robert
-- 
 Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de
 Pengutronix - Linux Solutions for Science and Industry
   Handelsregister:  Amtsgericht Hildesheim, HRA 2686
     Hornemannstraße 12,  31137 Hildesheim, Germany
    Phone: +49-5121-28619-0 |  Fax: +49-5121-28619-4