[PATCH] arm: update advice on kernel and FDT load address.

[Ian Campbell]

On Tue, 2013-07-30 at 15:04 +0100, Russell King - ARM Linux wrote:
> On Tue, Jul 30, 2013 at 02:56:10PM +0100, Ian Campbell wrote:
> > Actually I've just noticed that the existing text in
> > Documentation/arm/Booting only talks about zImage and 32KiB, so perhaps
> > not worrying about non-zImage is acceptable?
> 
> Straight binary kernels have tighter requirements, because they're _not_
> entirely position independent.  Firstly, with dynamic physical offset,
> they calculate that based on their position in physical space when
> they're first called.
> 
> So, with a PAGE_OFFSET of 0xc0000000 and a link address of 0xc0008000,
> a binary kernel image better be placed at 0xXXXX8000, and it _will_
> assume that RAM starts 32KiB below itself.  And yes, the 32KiB offset
> applies as the kernel uses TEXTADDR-16KiB to store the initial page
> tables.

OK, so in the non-zImage case 32KiB is a Requirement and not just a
recommendation. I'll update things to that affect.

This is turning out to be more complicated to write down than I
imagined!

Ian.