This is the mail archive of the
ecos-discuss@sources.redhat.com
mailing list for the eCos project.
Re: nested interrupt question
- From: "Eric de Jong" <list_ericdejong_10 at gmx dot net>
- To: <ecos-discuss at sources dot redhat dot com>
- Date: Tue, 17 Jun 2003 09:39:47 +0200
- Subject: Re: [ECOS] nested interrupt question
- References: <Law14-F63yTilzDhBlt00020791@hotmail.com>
Hello BRS/johnsonest,
> here, switch to svc mode,so enable interrupt, if interrupt occur at
>this time, r0-r5 stored in _exception_stack was corrupted,new r0-r5 will be
>pushed into _exception_stack.so last interupt failed to restore.right?
> my key question is that:
> 1) when interrupt can come again after cpsr updated? Is it immediately?
no, interrupt can not come again because the interrupt disable bit in cpsr is
not modified (and is set after handling an interrupt)
Further in the code the exeption stack is copied to the system stack, and thus
interrupts may get enabled again.
Eric.
--
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss