Re: [Qemu-devel] [PATCH] ARM targets: added ARM_FEATURE for Thumb-exception bit in system control register

[Peter Maydell]

On 5 September 2015 at 14:38, Mike Haben <address@hidden> wrote:
> Hi Peter,
>   You're quite right, on reading some more I see the correspondence with V7.
> However... while reading up on the Cortex-M3/4/7, I also found
> "Only Thumb and Thumb-2 instruction sets are supported in Cortex-M
> architectures, but the legacy 32-bit ARM instruction set isn't supported".
> Ugh - to avoid storing up a problem for the future, I think I better think
> it out again!

M profile exception handling is completely different to A/R
profile, and does not use this function at all (it is done
via arm_v7m_cpu_do_interrupt()). So that isn't a problem.
(In fact M profile doesn't even have an SCTLR register.)

thanks
-- PMM