Re: Mach on L4

[Farid Hajji]

> > > [...]  I envision more of a portability layer with an interface
> > > similar to that of the Linux kernel's architecture-dependent part
> > > (although hopefully a bit cleaner).  Let's call this KAL
> > > (``kernel-abstraction layer'') for a moment.
> [...]
> > As a *BSD-guy, I'm not very familiar with Linux internals, so I'll
> > have to figure out what you mean with "architecture-dependent part"
> > by diving in Linux's sources ;-). I'm acquainted to FreeBSD und NetBSD
> > internals though, so I can roughly imagine what you mean here.
> 
> To get the general idea, have a look at
> <URL:http://os.inf.tu-dresden.de/~hohmuth/prj/linux-on-l4/if/>
> (Postscript version at
> <URL:http://os.inf.tu-dresden.de/~hohmuth/prj/linux-on-l4/if.ps.gz>).
> In that report, I documented part of Linux' architecture-adaption
> layer's interface.  (The report corresponds to an ancient version of
> Linux, but it should be enough to give you the idea.)  Yes, I guess
> that it is similar to the BSDs' portability layer's interface.
Thanks, that is what I expected. Both Linux' and BSD's portability
layers are quite similar, but they differ in some places as well.

> > > - Don't assume your basic RPC mechanism can transfer system-object 
> > > handles 
> > >   (handles for threads, address spaces, etc.).
> > I understand the rationale behind this. It seems like this will be quite
> > hard to enforce though. Okay, I'll try to come up with a basic model.
> > I'd need help here though (suggestions, ideas, etc.)...
> 
> Your KAL interface doesn't have to have the same restriction, as long
> as a KAL implementation can deal with the issue internally.
OK, I'll have a first try at it and it will be always possible to
cleanup up the design in a few iterations before we start hacking.

Regards,

-Farid.

-- 
Farid Hajji -- Unix Systems and Network Admin | Phone: +49-2131-67-555
Broicherdorfstr. 83, D-41564 Kaarst, Germany  | address@hidden
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