ISR Argument Proposal Request

[Valette Eric]

Valette Eric wrote:

> Wait wait wait. I do not see the need of having access to the context 
> pushed on the stack for irq. I do see the need for exception handling.
> 
> In most RTEMS port, IRQ handling and execption handling are unified but 
> this is an error has exceptions are CPU scpecific (defined in the data 
> book) while IRQ frequently depend on board physical irq routing. Look at 
> PPC code or Ix86 code, they have two different API one for execption 
> handling and one for irq handling.
> 
> So please do not mix everything.

Thinking a little bit more, I furthermore think that the needed saved 
context in both case are differents : for real exception you need a full 
set of registers to try to recover from recoverable exceptions or for 
unrecoverable exception to debug your application (e.g remote debugging 
stuff). For irq, you only need to push the minimal set of registers 
needed to call a C function (usually the C scratch register defined in 
the ABI + some that you cannot avoid to use for low level (read raw) irq 
handling). So if we try to define the *right* context frame, we will 
never agree.

If Eric N. is listening, maybe he will comment on the various diffrent 
frame pushed by a 68030 or 38040 that depends on exception number and 
that you cannot manipulate so easilly.


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