Richard Bonomo writes:
>
>
> On Wed, 9 Aug 2006, Andrew Haley wrote:
>
> <snip>
>
> > MM, wrong. gcc might put something between the insns. Ok, try
> >
> > #define disable() \
> > ({ int __Status; \
> > __asm__ volatile ("clra ; save CPU status\n" \
> > "tfr cc,b\n" \
> > "orcc #0x50 ; disable interrupts" \
> > : "=d" (__Status)); \
> > __Status; })
> >
>
> OK, I get this error message:
>
> error: can't find a register in class `Q_REGS' while reloading `asm'
>
> which I think is generated by the companion "restore" function.
OK. Well, you have a worked example -- now you need to read the
manual about Extended Asm and do the same with restore() that you did
with disable().
> Here are the 3 function definitions as they
> currently stand:
>
> #define disable() \
> ({ int __Status; \
> __asm__ volatile ("clra ; save CPU status\n" \
> "tfr cc,b\n" \
> "orcc #0x50 ; disable interrupts" \
> : "=d" (__Status)); \
> __Status; })
>
> #define restore(X) \
> ({ int __Status = (X); \
> __asm__ ("tfr b,cc ; restore status" : : "d" (__Status) :
> "d", "cc"); }) [NOTE that the line wrapped in this message]
>
> #define enable() \
> __asm__ ("andcc #0xaf ; enable interrupts")
>
>
> The disable function is as you (Andrew) suggested.
> The restore function and enable function definitions
> are unchanged.
>
> BTW, I am not familiar with the syntax which was
> and it being used. What does (for example)
> ("tfr b,cc ; restore status" : : "d" (__Status) :"d", "cc")
> mean in this context?
Here, register d is being used as an input and it's also being
clobbered. That doesn't seem right to me. Something more like using
"=d" as the ouput and a matching constraint "0" for the input might
work better.
Andrew.
