Re: [ECOS] Use of IRQ on ARM

[Francesco Regazzoni <regazzoni at alari dot ch>]

Hi,

I applied your suggestions and worked fine.

Thanks a lot.


Andrew Lunn wrote:
> On Fri, Feb 24, 2006 at 03:18:43PM -0500, Francesco Regazzoni wrote:
> 
>>Hi,
>>
>>I have one questions about attaching an handler for the IRQ generated by
>>an ARM simulator.
>>
>>I generate my eCos using:
>>ecosconfig new integrator_arm9
>>ecosconfig add posix
>>
>>
>>
>>Then in my main.c I added this:
>>
>>static cyg_interrupt int1;
>>static cyg_handle_t int1_handle;
>>int initInterruptHandler(void) {
>>        cyg_vector_t int1_vector = CYGNUM_HAL_VECTOR_IRQ;
>>        cyg_priority_t int1_priority = 0;
>>
>>        cyg_interrupt_create (
>>                int1_vector,
>>                int1_priority,
>>                0,
>>                &MyHandler,
>>                NULL,
>>                &int1_handle,
>>                &int1);
>>
>>        cyg_interrupt_attach (int1_handle);
>>        cyg_interrupt_unmask (int1_vector);
>>        cyg_interrupt_enable();
>>}
>>
>>
>>and I call it here:
>>
>>int main(int argc, char **argv)
>>{
>>	initInterruptHandler();
>>	while (1) {}
>>}
>>
>>
>>I was expecting to see my MyHandler being called when IRQ is raised, but
>>when the pin of the CPU is up, I don't see my function being executed.
>>
>>
>>Am I missing something?
> 
> 
> The ARM processor only has two interrupts, IRQ and FIQ. So most chips
> contain the "Advanced Interrupt Controller". This multiplexes many
> interrupt sources onto the IRQ. See hal_platform_ints.h for a list of
> these interrupts. cyg_interrupt_create() installs an interrupt handler
> for one of these multiplex interrupts.
> 
> If you really want to install a handler for the IRQ, you need to use
> the function cyg_interrupt_set_vsr(). Note that the function you
> register must be a real interrupt handler, ie it must take care to not
> destroy any registers. This means you will need to write it in
> assembly language.
> 
>         Andrew

-- 
Ing. Francesco Regazzoni,
PhD student at ALaRI - USI, Lugano [http://www.alari.ch]

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