[PATCH v3 1/2] ARM: mmu64: allow to disable null pointer trap on zero page

[Sascha Hauer]

On Wed, Oct 21, 2020 at 04:51:39PM +0200, Michael Tretter wrote:
> Barebox uses the zero page to trap NULL pointer dereferences. However,
> if the SDRAM starts at address 0x0, this makes the first page of the
> SDRAM inaccessible and makes it impossible to load images to offset 0x0
> in the SDRAM.
> 
> Trapping NULL pointer dereferences on such systems is still desirable.
> Therefore, add a function to disable the traps if accessing the zero
> page is necessary and to re-enable the traps after the access is done.
> 
> The zero_page_memcpy function simplifies copying to the SDRAM, because
> this is the most common required functionality, but memtest also
> accesses the zero page and does not use memcpy.
> 
> Signed-off-by: Michael Tretter <m.tretter at pengutronix.de>

Applied, thanks

Sascha

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