Re: [MiNT] Interrupt in kernel functions

[Andreas Schwab <schwab@linux-m68k.org>]

Miro Kropáček <miro.kropacek@gmail.com> writes:

> just verifying -- do I understand it right that if CPU is in a kernel
> function (most likely because an user program used trap #n), all interrupts
> (autovectors -- MFP, VBL etc) are ignored as they got lower priority than
> trap #n exception?

Interrupts are blocked by the setting the interrupt mask field in the SP
register.  Non-interrupt exceptions don't modify the interrupt mask.

Interrupts are served on any instruction boundary, given their level is
above the current interrupt mask.  In the example of a trap insn, this
boundary is just after the CPU has set up to begin processing the
execption handler.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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