RE: [ECOS] context for creating interrupts on edb7312

["Aaron Case" <aaron dot case at dynazign dot com>]

Aaron Case<aaron.case@dynazign.com>
Firmware Engineer
Dynazign, Inc.
Charlotte, USA

> -----Original Message-----
> From: Gary Thomas [mailto:gary@mlbassoc.com]
> Sent: Friday, November 21, 2003 12:28 PM
> To: Aaron Case
> Cc: Ecos-Discuss
> Subject: RE: [ECOS] context for creating interrupts on edb7312
>
>
> On Fri, 2003-11-21 at 10:22, Gary Thomas wrote:
> > On Fri, 2003-11-21 at 09:32, Aaron Case wrote:
> > > > >
> > > > > Im looking for something along the lines of #define
> > > > hal_interrupts_enable
> > > > > cyg_interrupt_enable().
> > > >
> > > > Actually, there is no explicit call like this (anymore).  Interrupts
> > > > will get enabled when the scheduler "starts" the first
> thread (minimally
> > > > the 'idle' thread).  Thread contexts are initialized with interrupts
> > > > enabled and this just sort of falls out with the washing :-)
> > > >
> > > > --
> > > > Gary Thomas <gary@mlbassoc.com>
> > > > MLB Associates
> > > >
> > > >
> > >
> > > Gary,
> > >
> > > Thanks for the prompt answer. I was speaking more in the
> context of linking
> > > and compiling the image.
> > >
> > > I see that a call to enable interrupts is not necessary when
> threads are
> > > initialized.
> > >
> > > I also see the cyg_interrupt_enable in the map file, which
> jumps to the
> > > hal_interrupts_enable( from vector.S but not in the map file)
> code in the
> > > application.
> >
> > I'm not sure I understand what you mean by this (in the map file?), but
> > if a function isn't used (cyg_interrupt_enable() is not used by the
> > kernel except for a single test), then even if that function is defined
> > it doesn't end up in the resulting application.
> >
> > IMO there is absolutely no need to ever call cyg_interrupt_enable(),
> > except for the kernel test which tests it.
> >
> > If you need to manipulate the interrupt state (and there are very few
> > cases even for this), this is a better approach:
> >
> >    cyg_uint32 state;
> >    HAL_DISABLE_INTERRUPTS(state);   // Disables interrupts
> >      ...
> >    HAL_RESTORE_INTERRUPTS(state);   // Restore interrupts
>
> Or, even better when writing device drivers:
>
>    cyg_drv_isr_lock();
>      ...
>    cyg_drv_isr_unlock();
>
> --
> Gary Thomas <gary@mlbassoc.com>
> MLB Associates
>
>

Ok, Ive got it worked out now.

Thanks,
Aaron Case


-- 
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss