[U-Boot] [PATCH] relocation: Do not relocate NULL pointers.

[Scott Wood]

On Mon, Oct 05, 2009 at 11:18:11PM +0200, Wolfgang Denk wrote:
> Dear Peter Tyser,
> 
> In message <1254773254.24664.657.camel at localhost.localdomain> you wrote:
> > 
> > > 32 bit alignment of the BSS segment might not be sufficient. Be
> > > careful!
> > 
> > I've tried a few ways to ensure the BSS isn't at address 0x0, and they
> > all seem to have their shortcomings.  I'm currently leaning towards
> > doing something along the lines of the above, ie ORing 0x10 into the BSS
> > address.
> > 
> > I had assumed 8 or 16 bit alignment of the BSS would be sufficient.
> > Could you give a little background on your warning above about 32 bit
> > alignment being insufficient?
> 
> I don't know all flavours of Power machines, but gcc seems to align
> "double" on 64 bit boundaries. This makes me think it might be needed.

Plus, explicit alignment (cacheline, page, some DMA alignment
restriction, etc) could have been requested on something in the BSS.  I'd
keep it at least page-aligned if possible.

-Scott