history/port_to_another_microkernel: New. Based on other pages.

1 files changed, 5 insertions, 100 deletions

diff --git a/history/port_to_l4.mdwn b/history/port_to_l4.mdwn
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+++ b/history/port_to_l4.mdwn
@@ -1,108 +1,13 @@
-[[!meta copyright="Copyright © 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
-2009, 2010 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
 document under the terms of the GNU Free Documentation License, Version 1.2 or
 any later version published by the Free Software Foundation; with no Invariant
 Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
-is included in the section entitled
-[[GNU Free Documentation License|/fdl]]."]]"""]]
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
 
-[[!meta title="Porting the Hurd to L4: Hurd/L4"]]
+[[!tag stable_URL]]
 
-There was an effort to port the Hurd from [[microkernel/Mach]] to the
-[[L4_microkernel_family|microkernel/L4]].
-
-The idea of using L4 as a [[microkernel]] for a [[Hurd_system|hurd]] was
-initially voiced in the [[Hurd_community|community]] by Okuji Yoshinori, who,
-for discussing this purpose, created the [[mailing lists/l4-hurd]] mailing list
-in November 2000.
-
-The project itself then was mostly lead by Marcus Brinkmann and Neal Walfield.
-Even though there was progress -- see, for example, the
-[[QEMU image for L4|hurd/running/qemu/image for l4]] -- this port never reached a
-releasable state.  Eventually, a straight-forward port of the original Hurd's
-design wasn't deemed feasible anymore by the developers, partly due to them not
-cosidering L4 suitable for implementing a general-purpose operating system on
-top of it, and because of deficiencies in the original Hurd's design, which
-they discovered along their way.  Read the [[hurd/critique]] and a
-[[hurd/ng/position paper]].
-
-By now, the development of Hurd/L4 has stopped.  However, Neal Walfield moved
-on to working on a newly designed kernel called [[microkernel/viengoos]].
-
-Over the years, a lot of discussion have been held on the
-[[mailing lists/l4-hurd]] mailing list, which today is still the right place
-for [[next-generation Hurd|hurd/ng]] discussions.
-
-Development of Hurd/L4 was done in the `hurd-l4` module of the Hurd CVS
-repository.  The `doc` directory contains a design document that is worth
-reading for anyone who wishes to learn more about Hurd/L4.
-
-
-One goal of porting the Hurd to L4 was to make the Hurd independend of Mach
-interfaces, to make it somewhat microkernel-agnostic.
-
-Mach wasn't maintained by its original authors anymore, so switching to a
-well-maintained current [[microkernel]] was expected to yield a more solid
-foundation for a Hurd system than the decaying Mach design and implementation
-was able to.
-
-L4 being a second-generation [[microkernel]] was deemed to provide for a faster
-system kernel implementation, especially in the time-critical [[IPC]] paths.
-Also, as L4 was already implemented for a bunch of different architectures
-(IA32, Alpha, MIPS; SMP), and the Hurd itself being rather archtecture-unaware,
-it was expected to be able to easily support more platforms than with the
-existing system.
-
-A design upon the lean L4 kernel would finally have moved devices drivers out
-of the kernel's [[TCB]].
-
-
-One idea was to first introduce a Mach-on-L4 emulation layer, to easily get a
-usable (though slow) Hurd-using-Mach-interfaces-on-L4 system, and then
-gradually move the Hurd servers to use L4 intefaces rather than Mach ones.
-
-
-Neal Walfield started the original Hurd/L4 port while at Karlsruhe in 2002.  He
-explains:
-
-> My intention was to adapt the Hurd to exploit L4's concepts and intended
-> [[design_pattern]]s; it was not to simply provide a Mach
-> [[compatibility_layer]] on top of L4.  When I left Karlsruhe, I no longer had
-> access to [[microkernel/l4/Pistachio]] as I was unwilling to sign an NDA.
-> Although the specification was available, the Karlsruhe group only [released
-> their code in May
-> 2003](https://lists.ira.uni-karlsruhe.de/pipermail/l4ka/2003-May/000345.html).
-> Around this time, Marcus began hacking on Pistachio.  He created a relatively
-> complete run-time.  I didn't really become involved again until the second
-> half of 2004, after I complete by Bachelors degree.
-
-> Before Marcus and I considered [[microkernel/Coyotos]], we had already
-> rejected some parts of the Hurd's design.  The
-> [[open issues/resource management problems]] were
-> what prompted me to look at L4.  Also, some of the problems with
-> [[hurd/translator]]s were already well-known to us.  (For a more detailed
-> description of the problems we have identified, see our [[hurd/critique]] in the
-> 2007 July's SIGOPS OSR.  We have also written a forward-looking
-> [[hurd/ng/position paper]].)
-
-> We visited Jonathan Shapiro at Hopkins in January 2006.  This resulted in a
-> number of discussions, some quite influential, and not always in a way which
-> aligned our position with that of Jonathan's.  This was particularly true of
-> a number of security issues.
-
-A lange number of discussion threads can be found in the archives of the
-[[mailing lists/l4-hurd]] mailing list.
-
-> Hurd-NG, as we originally called it, was an attempt to articulate the system
-> that we had come to envision in terms of interfaces and description of the
-> system's structure.  The new name was selected, if I recall correctly, as it
-> clearly wasn't the Hurd nor the Hurd based on L4.
-
-
-The source code is still available in [CVS module
-`hurd-l4`](http://savannah.gnu.org/cgi-bin/viewcvs/hurd/hurd-l4/) (note that
-this repository has in the beginning also been used for Neal's
-[[microkernel/Viengoos]]).
+[[!meta redir=port_to_another_microkernel]]