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Re: L4 instead of gnumach?

Erik Verbruggen <ejv@cs.kun.nl> writes:

> Ok, I think the L4 stuff needs a bit of background. Special for Niels: I
> started doing a Sparc port, but there were some problems which are
> similair to those that the Alpha port has, so that's why I react.

Thanks for the info. I've tried browsing
http://os.inf.tu-dresden.de/L4/, but I haven't yet found the
definition of the "L4 µ-kernel API". Do I have to get some source
archive for that (and if so, which source; there seems to be several

My concerns last time I looked at L4 was

  (i) It was written in C++, which I dislike (that's a religious
      question, and this is not the right place to argue the details).

 (ii) The "clans and chiefs" model seemed odd. As I said, I think
      ports and send rights are quite sane and easy to understand.
      (see "An Ode to the Granovetter Diagram,

When I look now, it seems there are several implementations, not all
C++, which is good. So (i) seems solved. As for (ii), I would be happy
if you who are looking into L4 could tell me that you know how to do
HURD security or capability-style security on top of "clans and
chiefs", and that it won't kill performance. If you also have the time
to explain how to do it, that would of course be even better.

A short list of features one gains or loses when moving from Mach to
L4 would also be nice (efficient asyncronous "messages", network
transparent ipc, transfer of send rights, friendliness to higher level
ipc-services (say GNOME's corba stuff), etc).

Ok, that's a fair amount of questions. I would appreciate answers, but
I also understand if you want to spend your time hacking rather than


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