Q about PowerPC new exception processing.

[Eric Valette]

Sergei Organov wrote:
> 
> Hello,
> 
> Here is text from 'c/src/lib/libcpu/powerpc/new_exception_processing/cpu.h'
> (latest snapshot):
> 
> <BEGIN>
> /*
>  *  Does RTEMS manage a dedicated interrupt stack in software?
>  *
>  ...
>  *  If this is TRUE, CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
>  ...
>  */
> 
> #define CPU_HAS_SOFTWARE_INTERRUPT_STACK TRUE
> ...
> 
> #define CPU_ALLOCATE_INTERRUPT_STACK FALSE
> <END>
> 
> Actual definitions obviously come in contradiction with comments. Guess this
> is because usual interrupt stack allocation method is bypassed in the new
> exception processing code.
> 
> Strictly speaking, changing comments in the header means changing interface
> between RTEMS core and BSPs, and thus corresponding headers for other BSPs (as
> well as documentation) should also be changed :-( So the question arise:
> 
> Do we need to switch back to usual method of stack allocation or fix comments
> in the header?

I would suggest no to switch back as interrupt stack may need to be
initialized much more early than what is actually done in rtems...

I would change the comments because the defines value exactly describes
what is done in the code... Compatibility issue is usally an argument
for people that do not want to improve old code :-) New exception
management is required to implement either a kenel debugger or RDBG.
BEside it is also required for new interrupt handling API...


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