Re: [Qemu-devel] vexpress-a9 aborts when booting decompress code from a modified Linux kernel

[Peter Maydell]

On 16 October 2015 at 18:21, Ilya Lipnitskiy <address@hidden> wrote:
> Hi All,
>
> I am running into a curious issue with QEMU ARM, maybe a Linux/QEMU
> ARM expert could help before I filed a bug report. Is this a QEMU
> problem or is there a fundamental problem with my kernel change? QEMU
> builds before SHA 6ec1588e handle this kernel change just fine...
>
> I'm seeing a very early CPU abort if I add L1 cache invalidation logic
> in early Linux decompress code in arch/arm/boot/compressed/head.S.
> Essentially, if I add a copy of v7_invalidate_l1 from
> arch/arm/mm/cache-v7.S to __armv7_mmu_cache_on in head.S QEMU aborts
> somewhere inside the new code. Please see the head.S patch below:

It would be helpful if you said what the abort actually was
(ie what instruction do we abort on, what are the fault status/
fault address registers if applicable, etc).

(I assume you mean "we send an abort to the guest", not "QEMU's
C code calls abort(); if the latter, please provide a backtrace.)

thanks
-- PMM