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- From: jne@rice-chex.ai.mit.edu (Jeff Eisen)
- Newsgroups: comp.os.ms-windows.programmer.misc
- Subject: GP Trap device driver
- Message-ID: <1iveutINNimf@life.ai.mit.edu>
- Date: 12 Jan 93 21:58:53 GMT
- Organization: MIT Artificial Intelligence Lab
- Lines: 38
- NNTP-Posting-Host: rice-chex.ai.mit.edu
-
- Hi.
-
- I'm new to device driver programming, so excuse me if my
- terminology is not 100% correct.
-
- I have taken over a GP Fault device driver written by someone
- else. It almost always works ok.
-
- When in 386 enhanced mode in windows 3.1, the driver is hooked in with
- Hook_PM_... and defined to handle interrupt "0dh".
-
- Normally, when I get a GP fault, my handler kicks in and throws my
- application (lisp) into the debugger, instead of windows putting up
- the "Do you want to close" screen.
-
- I have a repeatable case though, where I'm not sure why its GP faulting,
- with the following behavior:
- 1) If I don't install my handler, there is no GP fault (at least there
- is no "Do you want to close" screen and CVW doesn't detect the fault).
- 2) If my handler handles the fault, I get thrown into my debugger
- in an almost-dead state.
- 3) If my handler declines the fault by chaining to the next handler
- in the chain, there is no GP fault (at least there is no "Do you
- want to close" screen and CVW doesn't detect the fault.
-
- Is it possible that there are some classes (error codes?) of GP faults
- that my device driver is supposed to know to ignore?
-
- Is there any good way to debug this (I've never used WDEB386 or WINICE,
- but I could learn them if necessary)?
-
- This is a real bitch to debug because the error only happens when I'm
- set up so that CVW won't catch the error :-(
-
- Thanks in advance for any help or ideas.
-
- Jeff Eisen
- jne@ai.mit.edu
-