[U-Boot] [PATCH] powerpc: do not fixup NULL ptrs

[Joakim Tjernlund]

Andre Schwarz <andre.schwarz at matrix-vision.de> wrote on 2010/10/26 14:34:57:
>
> All,
>
> >
> >> Having a look at include/asm/global_data.h gives some 40 ulongs for my
> >> MPC8377 system.
> >> Current CONFIG_SYS_GBL_DATA_SIZE= 0x100 which should be enough.
> >>
> > Indeed. I was asking because I just discovered that most of the
> > PowerPC boards are actually broken in this respect - 89 % of them,
> > 170 out of 191 :-(
> >
> >
> >> The system is still dead after removing the 4 nops after _start.
> >>
>
> actually I'm facing another issue and don't now whether this might be
> related to this thread or not.
>
>
> Just before relocation in arch/powerpc/lib/board.c the CPU gets a "check
> stop" followed by reset during "memset()" in line 493.
>
> [snip]
> DRAM:  256 MiB
> Top of RAM usable for U-Boot at: 10000000
> Reserving 341k for U-Boot at: 0ffaa000
> Reserving 512k for malloc() at: 0ff29f80
>
> - reset -
>
> U-Boot 2010.09-00488-g5edbadb-dirty (Oct 26 2010 - 14:16:00) MPC83XX
>
> Reset Status: Check Stop, External/Internal Soft, External/Internal Hard
>
>
> I know that DDR might not be 100% stable but it is basically set up
> properly.
> Removing the memset yields the next debug messages before resetting
> again while setting up SP.
>
> Is the DDR required to work 100% for a simple write operation or might
> there be another problem ?

Yes, DDR must be correct. You might get a bit further by turning off
the data cache.