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mailing list for the eCos project.
RE: semaphore bug??
- To: "'ecos-discuss at sources dot redhat dot com'" <ecos-discuss at sources dot redhat dot com>
- Subject: RE: [ECOS] semaphore bug??
- From: Geoff Patch <grp at cea dot com dot au>
- Date: Wed, 15 Aug 2001 11:49:32 +1000
Hi Folks,
> I don't think you can post to a semaphore from an ISR. You'll
> have to run a DSR and do it there. There's a table in the eCos
> Reference Manual (Device Driver Interface to the Kernel) that
> shows what functions may be called from an ISR. About the only
> thing you can do is ack/mask/unmask interrupts and run a DSR.
This is correct, and I recall other postings to the list about this issue.
It's obviously a fairly common misconception. I come from a pSOS
background, where it is possible to post a semaphore in an ISR, and I also
spent a bad week stumbling over this exact issue .
Could I suggest to the eCos team that an explicit statement of *exactly*
what can and cannot be done in an ISR be inserted into the "eCos Interrupt
Model" section of the Reference manual? I'm sure that this would help a lot
of newbies (like me) retain their sanity. :-)
And while I'm writing, I'd like to say that I think eCos is a great piece
of gear. Hats off to you guys.
Cheers
Geoff
------------------------------
Geoff Patch
Senior Software Engineer
CEA Technologies
Canberra Australia
02-6213 0141