Re: [Qemu-devel] [ARM] Cortex-R4F and VFP3-D16

[Peter Maydell]

On 1 March 2013 12:07, Fabien Chouteau <address@hidden> wrote:
> On 03/01/2013 12:32 PM, Peter Maydell wrote:
>> I think you're going to have to run some tests on the actual
>> hardware to find out what it really does. Specifically, what
>> are the values of SCTLR.IE, SCTLR.EE and CPSR.E when you think
>> you're in big-endian mode?

> SCTLR.IE and SCTLR.EE are both set to 1 at reset and the values
> cannot be changed.

OK, that makes sense. I think it's also a reasonable thing for
qemu's qemu-system-armeb model to present to the guest. Have
you changed QEMU to report IE and EE (and CPSR.E) as always-1,
or does your guest code just not look at them?

> BTW, our run-time works both on QEMU and a real-board, that's also why
> I'm confident that there are no endianness issue.

The trouble is that you can have two separate bits of QEMU
which both model the endianness incorrectly but in such
a way that the two errors cancel each other out and the
guest-visible behaviour looks correct...

-- PMM