OpenEuphoria

2. Re: Causeway Error Codes

• Posted by Robert Craig <rds at EMAIL.MSN.COM> Jan 10, 1998
• 1131 views
• Last edited Jan 11, 1998

Pete Eberlein writes:
> Hey Rob, do you have a list of what the Causeway exception
> errors mean? Like "Exception: 0E, Error code: 0004"?

Those aren't specific to CauseWay. They are Intel-defined
exception numbers and error codes. Exception 0E would be
"Page Fault". The error code gives some detail of the page fault
but I don't think it's of much use. In general, I find the CauseWay
CW.ERR file to be almost useless in debugging ex.exe, so
I imagine it is even less useful for a Euphoria programmer.
Since you do a lot of assembly language work maybe it would
be of some use to you.

A CauseWay error typically occurs because you have
tried to access some high memory that doesn't belong to you.
CauseWay won't stop you from messing up low (640K) memory,
but it has the ability to catch *some* bad references to high
memory.

Here's a list of the Intel exceptions for what it's worth:

0. Division by Zero
1. Debug Exceptions
2. ?
3. Breakpoint
4. Overflow
5. Bounds Check
6. Invalid Opcode
7. Device Not Available
8. Double Fault
9. ?
A. Invalid TSS
B. Segment Not Present
C. Stack Fault
D. General Protection
E. Page Fault
F.  ?
10. Floating-point Error
11. Alignment Check

The "error code" is produced only for some exceptions.
It gives you some further debug info. If it's an even number
it means the exception was caused by your program, not some
other event external to your program. Beyond that, it gets
very cryptic, having to do with virtual memory page descriptors.

For your OE exception, I would guess that you have tried
to access a bad high-memory address, or less likely, if you
are handling hardware interrupts, you have not locked all
the data and code memory needed by your exception handler,
and some of it got swapped out.  See lock_memory()

Regards,
     Rob Craig
     Rapid Deployment Software