BSP for 405EX

[Nigel Spon]

On 29/03/2008, at 1:36 PM, Till Straumann wrote:
>>
> I'd like to add my 2 cents here; recently a framework for supporting  
> exceptions
> and interrupts has been added under
>
> libcpu/powerpc/new-exceptions/bspsupport
>
> please consider using that framework rather than deriving your own  
> variants
> from
>
> libbsp/powerpc/shared/irq/irq_asm.S
> libbsp/powerpc/shared/vectors/vectors.S
> libbsp/powerpc/virtex/irq_init.c
> etc.


I have made a start on BSP for the 405GP/405EX which uses the  
bspsupport code, and it is basically working. However, it looks as  
though I may be losing interrupts and I suspect I have not implemented  
BSP_enable_irq_at_pic or C_dispatch_irq_handler correctly.

My question is, should I be expecting BSP_disable_irq_at_pic to be  
potentially called from within the interrupt handlers called by  
bsp_irq_dispatch_list? If so, the implementation of  
BSP_disable_irq_at_pic can't just write to the PIC hardware, because  
the PIC hardware has to be used to inhibit any level-sensitive  
interrupts from recurring the moment bsp_irq_dispatch_list re-enables  
interrupts - because the interrupt handlers haven't cleared the source  
yet. The exact sequence of events at this point then gets a bit  
tricky...

Thanks,

---
" The boy stood on the burning deck, whence all but he had fled!
Twit."

Michael Hamel
ADInstruments Ltd, Dunedin, NZ