[ECOS] Random questions about ARM vectors.s

[Bill Diehls <billabloke at yahoo dot com>]

Hi All,
We fear we may have to significantly modify hitherto
untouched portions of vectors.S in order to workaround
the interrupt issues we've been battling with the
Gameboy (such as the IRQ and exception handling
routines.)  We have a couple of random questions: 

-- When calling C-code from the IRQ routine (such as
hal_IRQ_handler) the stack frame (v6) is passed as an
argument.  Is this for debugging purposes?  Does gdb
use this?

-- Toward the end of the IRQ routine (close to the
switch back to IRQ mode), there are 2 nop
instructions.  Not that it matters much, but we've
been curious why they are there.  (On a related note,
why are the IRQ and FIQ disable bits set separately
from the mode bits at the end of the IRQ routine?)

thanks!
--bill
 



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