RE: [ECOS] cyg_drv_interrupt_create ()

["Trenton D. Adams" <tadams at extremeeng dot com>]

> -----Original Message-----
> From: rob.wj.jansen@philips.com [mailto:rob.wj.jansen@philips.com] 
> Sent: Friday, June 22, 2001 2:05 AM
> To: tadams@extremeeng.com
> Cc: ecos-discuss@sources.redhat.com
> Subject: RE: [ECOS] cyg_drv_interrupt_create ()
> 
> 
> >> The interrupt number. Most times these map directly to 
> what you would 
> >> expect. But you can get the definitions by including 
> >> <cyg/hal/hal_intr.h>. Look at the header (and possibly what it 
> >> includes) to find the value required. Yes our 
> documentation could be 
> >> improved :-|.
> >
> >Does it have to be defined in the <cyg/hal/hal_intr.h> 
> header file to 
> >be a useable interrupt?
> 
> Yes it should.
> The interrupt number you specify is an index into an 
> interrupt table. The ARM processor only has one IRQ and one 
> FIQ pin and on most boards these lines are connected to an 
> interrupt controller (this may be part of a chip with an 
> embedded ARM core). In the hal for the arm the interrupt 
> routine (hal/arm/arch/current/src/vector.S, label 
> handle_IRQ_or_FIQ:) will call the hal_IRQ_handler function 
> defined in hal/arm/edb7xxx/current/src/edb7xxx_misc.c. This 
> latter function will then query the interrupt controller to 
> determine where the interrupt comes from and return this as a 
> number. Now the IR handler in vectors.S will get the address 
> of the function from a table (hal_interrupt_handlers) and 
> call the corresponding interrupt.

I'm counting three interrupt lines, and an FIQ line myself.  Does this
most likely mean that I will have to add the handling for the interrupt
that I'm using?

 
> I don't know details about the board you are using but if you 
> are using a free interrupt or an interrupt not yet 
> used/defined by eCos you should define one yourself. The only 
> thing is that you have to make sure that this is the same 
> number as returned by hal_IRQ_handler. You will also want to 
> add this to hal/arm/edb7xxx/current/include/hal_platform_ints.h.

What's a free interrupt?

> Best is to first have a good look at the code, I did some 
> single stepping through the interrupt handler before I 
> understood what is going on (but I guess this is only 
> possible with a hardware debugger and not with a GDB stub).

What's a hardware debugger?  Doesn't sound like I want to get into using
a hardware debugger.