[Qemu-devel] [PATCH] QEMU: ARM: boot: Load kernel at an Image friendly address

Peter Crosthwaite peter.crosthwaite at xilinx.com
Wed Apr 2 05:11:59 PDT 2014


On Wed, Apr 2, 2014 at 3:10 AM, Peter Maydell <peter.maydell at linaro.org> wrote:
> On 25 March 2014 03:34, Joel Fernandes <joelf at ti.com> wrote:
>> Loading kernel at offset 0x10000 works only for zImage, but not for Image,
>> because the kernel expect the start of decompressed kernel (.head.text) to be
>> at an address that's a distance that's 16MB aligned from  PAGE_OFFSET +
>> TEXT_OFFSET (see vmlinux.lds.S). This check is enfornced in __fixup_pv_table in
>> arch/arm/kernel/head.S TEXT_OFFSET is 0x00008000, so a 16MB alignment needs to
>> have a "0x8000" in the lower 16 bits so that they cancel out. Currently the
>> offset Qemu loads it at is 0x10000.
>>
>> With zImage, this need is met because zImage loads the uncompressed Image
>> correctly, however when loading an Image and executing directly Qemu is
>> required it to load it at the correct location. Doing so, doesn't break Qemu's
>> zImage loading. With this patch, both zImage and Image work correctly.
>>
>> Signed-off-by: Joel Fernandes <joelf at ti.com>
>
> Reviewed-by: Peter Maydell <peter.maydell at linaro.org>
>

Like others, I have been carrying this change locally. Good to see it up!

Reviewed-by: Peter Crosthwaite <peter.crosthwaite at xilinx.com>
Tested-by: Peter Crosthwaite <peter.crosthwaite at xilinx.com>

> I'll put this in target-arm.next after 2.0 has released.
>
> thanks
> -- PMM
>



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