This document describes what traps are, how they work and how they are handled by the SunOS kernel (applicable to both Solaris 1 and Solaris 2, I use the term SunOS as I am talking about the operating system itself and not the complete package of X-Windows and utilities that make up the full Solaris product).
We will look at traps for SPARC versions v7, v8 and v9 (v7 and v8 traps are essentially identical and so I'll be treating v7 and v8 as one). In places, we will have to differentiate between the v7/v8 and v9 quite extensively as there are significant differences between the two.
I assume that the readers are familiar with SPARC registers but I will give some expansion on the more obscure ones as I go :-)
Finally, I have made every effort to make this accurate as well as
informative but at the same time without too lengthy descriptions.
Even so, in parts it may be heavy going and plain ascii doesn't
leave much scope for clear diagrams (if you're reading the HTML
version of this, you might get lucky and see a picture here and
there. However, I try to avoid this due to the invariably slow
download of images). Feel free to post or email
questions and comments and corrections if you've spotted an error!
1.1 Who should read this document?
Anyone who wants to know more about traps in detail on the SPARC
architecture. I strongly recommend that you refer to one of these
two books for more information:
The SPARC Architecture Manual, Version 8 ISBN 0-13-099227-5
The SPARC Architecture Manual, Version 9 ISBN 0-13-825001-4
as they contain more detail on some of these topics. Also, take a
look at SunOS on SPARC, a white paper by Steve R. Kleiman and
D. Williams. This gives a good overview of SunOS on the SPARC
architecture, although it doesn't cover SPARC v9 as that was not
in existence at the time of writing. This paper (and others) is
available in:
The SPARC Technical Papers ISBN 0-387-97634-5
1.2 Copyright and Reproduction Information
This text is totally free for anybody to use or redistribute. I
would only request that you do NOT assume this text to be error
free and also that you at least credit me for putting the time
in to write the darn thing in the first place :-)