From 2968bbdfc5d2ab381bbc9ce88e6ae90493cba2cb Mon Sep 17 00:00:00 2001 From: Thomas Schwinge Date: Tue, 29 Mar 2011 12:19:10 +0200 Subject: faq/which_microkernel: Resurrect Olaf's text, and work on it some more. --- faq/which_microkernel.mdwn | 44 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 42 insertions(+), 2 deletions(-) (limited to 'faq') diff --git a/faq/which_microkernel.mdwn b/faq/which_microkernel.mdwn index 608e6b3f..0852cf09 100644 --- a/faq/which_microkernel.mdwn +++ b/faq/which_microkernel.mdwn @@ -8,8 +8,48 @@ 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]]."]]"""]] -[[!meta title="What happened with the ports to the L4 / Coyotos / Viengoos +[[!meta title="What happened with the Hurd ports to the L4 / Coyotos / Viengoos microkernels?"]] -This story is told on the page about the + + +It is a frequently asked question, which microkernel the Hurd should be based +upon assuming that [[microkernel/Mach]] is no longer considered state of the +art, and it is well known that there has been a lot of discussion about this +topic, and also some code produced, but then, years later, the Hurd is still +based on [[GNU Mach|microkernel/mach/gnumach]]. + +Around the turn of the millenium, some of the Hurd developers began +experimenting with using other [[microkernel]]s for the Hurd, as they have been +encountering a number of fundamental design issues with the [[Mach +microkernel|microkernel/mach]], mostly with respect to +[[open_issues/resource_management_problems]]. + +At that time, L4 (Pistachio) was the prime candidate. A reimplementation of +the Hurd on this microkernel looked promising, and got pretty far (running some +simple POSIX programs, such as `banner`). However, over time some lingering +design issues turned out to be fundamental problems: the original L4 is not +suitable for building object-capability systems like the Hurd. Thus +development was aborted in 2005. + +During that process, Neal Walfield and Marcus Brinkmann started on a period of +research on other microkernels, getting in deeper contact with other +researchers. There was a lot of discussion, and a lot of good ideas produced, +but a straight-forward port of the Hurd to such a modern microkernel (Coyotos, +or the new L4 variants, for example) didn't seem feasible to them anymore: they +found microkernel design and system design to be interconnected in very +intricate ways, and this demanded design changes in the Hurd's core itself. + +Based on this experience, the next step was to write an own microkernel +instead, which Neal Walfield began doing with his experimental +[[microkernel/Viengoos]] project, for his research on resource management. +Currently he works in another research area though, and thus Viengoos is on +hold. + +Note that while none of the microkernel research work is active now, the +previous experiments already yielded a lot of experience, which will be very +useful in the further development / improvement of the mainline (Mach-based) +Hurd implementation. + +For more detauls about this topic, please see our history page about the [[history/port_to_another_microkernel]]. -- cgit v1.2.3