esk at ira.uka.de
Wed May 24 14:32:31 CEST 2006
> Sigma0 has disappeared from the latest Pistachio kernels as well, so
> even the information above is version dependent.
What?!? Sigma0 has always come with the kernels and will always do.
How else are the applications supposed to get access to memory?
> Learning about L4 in general can be frustrating as, being in
> significant part, a research vehicle, much of the background
> documentation is in conference papers and thesis extracts, and dates
> quickly (L4::Pistachio is evolving very rapidly). The background
> material is still useful, but you need to be aware that it's not
> always relevant to the latest releases.
Actually, the Version X.2 API and the corresponding L4Ka::Pistachio
implementation is evolving rather slowly. Or put in a better way, the
API is getting close to feature complete and there are as such not
many more changes to the kernel (for the current API).
> The source code is your friend here (although the user manual and
> refman are reasonably up to date). Most of the code is well written
> and structured (if sparsely commented), although it requires very
> good C++ and CPU platform knowledge to follow in detail.
The source code is *not* supposed to be your friend. This is not
Linux. The refman is the definite source for kernel behaviour; and
yes, the refman is updated whenever the API changes (with a changelog
history entry in the preamble). If there's something unclear in the
refman then please ask.
Any hack in the kernel implementation are either temporary solutions
or used for testing purposes. Don't rely on them.
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