Re: [PATCH 6/6] target-arm/cpu.h: document why env->spsr exists

Peter Maydell
2015-03-11T15:48:06Z

On 25 February 2015 at 16:02, Alex Bennée <alex.bennee@linaro.org> wrote:
> I was getting very confused about the duplication of state. Perhaps we
> should just get rid of env->spsr and use helpers that understand the
> banking?

I've already disagreed with this. I would suggest putting
tentative questions about future direction of the codebase
below the '---' rather than in the commit log :-)

> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 11845a6..d7fd13f 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -155,6 +155,11 @@ typedef struct CPUARMState {
> This contains all the other bits. Use cpsr_{read,write} to access
> the whole CPSR. */
> uint32_t uncached_cpsr;
> + /* The spsr is a alias for spsr_elN where N is the current
> + * exception level.

This isn't true for AArch32 (which has multiple different SPSRs
any of which might be the one in env->spsr when we're at EL1).

-- PMM