Why is CPU_ISR_PASSES_FRAME_POINTER == FALSE on sparc?

[Sebastian Huber]

Hello,

I work currently on this ticket:

https://devel.rtems.org/ticket/4458

This is also related to the strange set_vector() function. Why do we 
have this:

/**
  * Does the RTEMS invoke the user's ISR with the vector number and
  * a pointer to the saved interrupt frame (1) or just the vector
  * number (0)?
  *
  * The SPARC port does not pass an Interrupt Stack Frame pointer to
  * interrupt handlers.
  */
#define CPU_ISR_PASSES_FRAME_POINTER FALSE

I noticed that in bsp_spurious_initialize() we use this default handler:

static rtems_isr bsp_spurious_handler(
    rtems_vector_number trap,
    CPU_Interrupt_frame *isf
)
{
   CPU_Exception_frame frame = {
     .trap = trap,
     .isf = isf
   };

We also have in cpu_asm.S:

         sethi    %hi(SYM(_ISR_Vector_table)), %g4
         or       %g4, %lo(SYM(_ISR_Vector_table)), %g4
         and      %l3, 0xFF, %g5         ! remove synchronous trap indicator
         sll      %g5, 2, %g5            ! g5 = offset into table
         ld       [%g4 + %g5], %g4       ! g4 = _ISR_Vector_table[ vector ]


                                         ! o1 = 2nd arg = address of the ISF
                                         !   WAS LOADED WHEN ISF WAS 
SAVED!!!
         mov      %l3, %o0               ! o0 = 1st arg = vector number
         call     %g4

So, why is CPU_ISR_PASSES_FRAME_POINTER set to FALSE when the handler is 
actually called with the frame pointer and some handler actually use it?

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