How much NEON state should be saved in a context switch? (xilinx zynq)

Stephen Tether tether at
Wed Jan 21 07:06:19 UTC 2015

On 1/20/15 10:01 PM, Sebastian Huber wrote:
> ...
> The context switch code changes the stack and in case a thread is
> pre-empted via an interrupt it will resume execution in the exception
> epilogue which restores the volatile registers. In
> _ARMV4_Exception_interrupt you have to consider that this code executes
> with interrupts disabled. If you want to see this in action see test
> spcontext01 and set a break point to _CPU_Context_volatile_clobber and
> _CPU_Context_validate.

I understood about interrupts being disabled. What I didn't understand
was that the SVC stack is the task stack. That changes everything. In
the back of my mind I was thinking that the task stack was the user-mode
stack. Too much Linux on the brain, I guess. Thanks for your patience.

- Steve

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