Barebox newbie questions : arch/arm/{plat, mach} split and interrupts

[Antony Pavlov]

On 13 November 2011 22:29, Robert Jarzmik <robert.jarzmik at free.fr> wrote:

> As I'm a bit new to barebone, and after reading a bit the code for the ARM
> architectures, I have questions :
>
> ...
>
>  (2) In arch/arm, I understand that interruptions are never used (do_irq()
>     implementation is quite clear about that). Is that a design decision and
>     why ?
>     If so, I suppose that active polling for each device is required. Am I
>     right here ?
>

Barebox is a firmware. So there are two main requirements for firmware:
 * easy adaptation for new board (new board revision);
 * small RAM/ROM footprint.

No interrupt support will help you to fulfill the both requirements.

Moreover, if you have a board with some interrupt damage (e.g. PCI
interrupt pin broken or
erroneously routed) you can start firmware and easy find the problem.
 But if your firmware use the interrupts and your board have broken
PCI interrupts
and console on RS232 connected via PCI  when ... you will have very
funny hardware quest :)))

-- 
Best regards,
  Antony Pavlov