[U-Boot] [MPC83xx] broken patch "do not fixup NULL ptrs" ?

[André Schwarz]

On Fri, 2010-10-22 at 16:56 +0200, Joakim Tjernlund wrote:
> André Schwarz <andre.schwarz at matrix-vision.de> wrote on 2010/10/22 
> 16:30:49:
> > 
> > Joakim,
> > 
> > 
> > your commit d1e0b10accdbac2e0a8b2cbf7c589645442f87c5 renders my MPC8377
> > based board unbootable.
> > 
> > 
> > Two weeks ago I got this after power on : 
> > 
> > 
> > U-Boot 2010.09-00486-gfda6278-dirty (Oct 22 2010 - 16:19:20) MPC83XX
> > 
> > Reset Status:
> > 
> > CPU:   e300c4, MPC8377, Rev: 2.1 at 533.333 MHz, CSB: 266.667 MHz
> > Board: Matrix Vision MergerBox
> > ....
> > 
> > 
> > 
> > After rebasing my work to current master completely silences the serial
> > line and the CPU doesn't come up. Bisection leads to your patch.
> > 
> > reverting it makes the board work again.
> > 
> > Any ideas ?
> 
> Yes, the problem is else where. This code runs after relocation to RAM.
> I had a similar problem and the reason was the patch:
>  "powerpc: Remove warm reset entry point"

hmm, ok.
But what's the root cause ?

> 
> Try sticking 4 nop's right after _start:
> in start.S
> 

... and why should this work ?
Has this something to do with trial and error ?

Can you shed some light on this ?



Regards,
André




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