Re: [Xenomai-core] Xenomai on PXA255

[Stelian Pop <stelian.pop@domain.hid>]

Le lundi 29 mai 2006 à 16:14 +0200, Bart Jonkers a écrit :

> > The Ipipe patch for ARM only support the integrator platform for
> > now. There exist patch for another ARM platform, but it exist only as
> > a separated patch. Looking at the patch contents it seems that the only
> > patched files specific to the integrator architecture are :
> > arch/arm/mach-integrator/core.c
> > arch/arm/mach-integrator/integrator_cp.c
> > include/asm-arm/arch-integrator/entry-macro.S
> > include/asm-arm/arch-integrator/platform.h
> > include/asm-arm/arch-integrator/timex.h
> > 
> > Looking rapidly at these files, it seems that the machine specific
> > functions and variables are reduced to:
> > 
> > int __ipipe_mach_timerint;
> > int __ipipe_mach_timerstolen;
> > unsigned int __ipipe_mach_ticks_per_jiffy;
> > 
> > void __ipipe_mach_acktimer(void);
> > unsigned long long __ipipe_mach_get_tsc(void);
> > void __ipipe_mach_set_dec(unsigned long reload);
> > unsigned long __ipipe_mach_get_dec(void);
> > 
> > If you provide the same variables and functions for the PXA platform, I
> > think there is no modification to be done at Xenomai level.

Gilles is 100% correct. All the platform specific code has to do is
provide the low level timer manipulation functions.

> I found this out already. But it would be a easier to implement this
> functions if I know what they have to do. So could somebody give an
> explanation of this variables and functions?

Well, __ipipe_mach_acktimer acks the timer, __ipipe_mach_get_tsc returns
the TSC of the platform, __ipipe_mach_set_dec sets the decrementer etc.
Should I go on ?

If you have specific questions feel free to ask. But I suggest you read
and try to understand the code first.

Stelian.
-- 
Stelian Pop <stelian.pop@domain.hid>