[PATCH] score: Delete _CPU_Context_Fp_start()

Sebastian Huber sebastian.huber at embedded-brains.de
Thu Jan 26 06:32:38 UTC 2017



On 25/01/17 17:24, Joel Sherrill wrote:
> I had another thought that we need to be sure that the
> reason for adjusting the starting FP context pointer
> to not be the base address of the FP context area
> should be clear.
>
> For architectures where you are just linearly saving the FPU
> registers, it is just a normal structure.
>
> For architectures like the m68k where the FPU state is saved
> as a stack which grows down, the adjustment should have
> a comment to explain it. Even if it is done inline in the
> context initialization.

Thanks for the review. I added a comment for m68k:

     /*
      * The floating-point context is saved/restored via FSAVE/FRESTORE 
which
      * use a growing down stack.  Initialize the stack and adjust the 
FP area
      * pointer accordingly.
      */
     #define _CPU_Context_Initialize_fp( _fp_area ) \
        { \
          uint32_t *_fp_context = _Addresses_Add_offset( \
            *(_fp_area), CPU_CONTEXT_FP_SIZE - 4); \
          *(--(_fp_context)) = 0; \
          *(_fp_area) = (void *)(_fp_context); \
        }

It is the only architecture supported by RTEMS that uses this model.

-- 
Sebastian Huber, embedded brains GmbH

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