Subject: Need help from core-knowing people
To: None <amiga@NetBSD.ORG>
From: Daniel Widenfalk <>
List: amiga
Date: 01/21/1995 21:54:46

First I'd like to say that if you find another posting from me which is much
longer and contains some source, ignore it. I've found out more and the
info in that posting is outdated. (I haven't seen it myself. I posted it
TWO days ago!)

The problem is: I realy need to get in touch with someone who knows a lot
about interrupts, virtual <-> physical mapping, process scheduling ...

My problem is:
st_mode_sense gives my Fastlane driver a buffer which is located on some
process' stack (&mode_sense I think) but when my driver (which is interrupt
driven almost always) gets to the data in phase I find that the virtual
to physical mapping has changed! My suspicion is that a process switch
has occured and with that, the interrupt routine runs on a diffrent stack
=> The data gets transfered to an illegal adress.

If you know how to work around this PLEASE let me know how. I could force
my code to do non-interrupt code for all transfers except read and write
but I'd rather not!

I've hunted this bug for ~4 hours a day for seven days now and I'm getting
very sick of it!

Best regards
/Daniel Widenfalk