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From what I understand, the Mach kernel which is now used in XNU is not the Mach micro kernel (3.0 >) but based upon the pre-micro-kernel 2.5 version of Mach.
by gillianseed 13y ago
From what I understand, the Mach kernel which is now used in XNU is not the Mach micro kernel (3.0 >) but based upon the pre-micro-kernel 2.5 version of Mach.
I'm not sure where I read this originally but I just googled this source which seems to back it up:
http://www.roughlydrafted.com/0506.mk3.html http://www.roughlydrafted.com/0506.mk3.html
- asveikau 13y agoI am not intimately familiar with the history of Mach, but what I do see is that in the late 80s and early 90s these two groups (NeXT and GNU) seeing Mach as the future (a position that makes no sense at a later time), and having vastly different outcomes. I don't know much about how these people work, but I always figured Mach at Apple is just about momentum and familiarity of contributors, rather than technology. NeXT hired Tevanian who worked on Mach at CMU, they spent roughly a decade hacking on Mach, then Apple did the same. I'd imagine they employ people who know Mach well and haven't seen it as worthwhile to replace it. I even remember they had this goofy project "MkLinux", which sought to put Linux in the position that BSD carries with XNU, on top of Mach... Just goofy stuff, unless you figure they had Mach hackers on staff.
- empthought 13y agoAccording to the Apple docs XNU is based on Mach 3.0. https://developer.apple.com/library/mac/documentation/Darwin/Conceptual/KernelProgramming/Mach/Mach.html https://developer.apple.com/library/mac/documentation/Darwin...
- valleyer 13y agoThat's misleading. Apple merged in a bunch of Mach 3 code but still maintains the architecture of Mach 2.5 (i.e., Mach + BSD both running in supervisor mode in one big monolith; no BSD server; xnu is not a microkernel…).