RE: [ECOS] context for creating interrupts on edb7312

[Gary Thomas <gary@mlbassoc.com>]

On Fri, 2003-11-21 at 08:06, Aaron Case wrote:
> > > It appears that cyg_interrupt_enable() acts directly on the CPSR in
> > > ARM(after viewing the ASM), but my MAJIC debugger tells me that the CPSR
> > > doesn't change unless the scheduler is started. So what in eCos blocks
> > > access to the interrupt bits in the CPSR when the scheduler is
> > not running?
> >
> > Nothing - remember eCos is pretty light weight; you can do most anything
> > you want at any time.  That said, it's not a good idea to be messing
> > around with the interrupts and you should never blindly just enable them
> > (unless you want a broken system!)
> >
> > --
> > Gary Thomas <gary@mlbassoc.com>
> > MLB Associates
> >
> >
> 
> Ok, I see now that cyg_interrupt_enable runs checks before enabling
> interrupts to prevent you from hosing the hole system.
> 
> So that I can hose my system fully, I have one last question.
> 
> (Last question) Where is the attachment between the generic call
> cyg_interrupt_enable()  and the hardware specific hal_interrupts_enable
> macro in vectors.S?
> 
> 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


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