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Annotation of OSKit-Mach/=announce-oskit-mach-1.2.90, revision 1.1

1.1     ! root        1: I am pleased to announce the availability of an initial development
        !             2: snapshot of a new variant of the Mach kernel, which I am tentatively
        !             3: calling OSKit-Mach.  The starting point for this variant is the current GNU
        !             4: development version of Mach (aka GNUmach).  The difference between GNUmach
        !             5: and OSKit-Mach is that I have entirely ripped out all the old Mach and
        !             6: Linux device driver code and several parts of the i386 hardware support
        !             7: code and replaced them with uses of the OSKit's hardware support and device
        !             8: driver libraries.
        !             9: 
        !            10: Please note that although I am a sometime employee of the University of
        !            11: Utah's Flux Group (makers of the OSKit), and I am a Hurd developer and a
        !            12: long-time volunteer and former employee of the GNU Project, this is wholly
        !            13: a personal project of mine that I began on my own without consulting
        !            14: anyone.  I am using the Hurd project's CVS repository for OSKit-Mach
        !            15: because it is convenient for me (seeing as it's a branch off the current
        !            16: gnumach development) and is a convenient way for me to make my code
        !            17: available, and obviously I am encouraging use of the University of Utah's
        !            18: OSKit, but that should not be misconstrued as an endorsement of my project
        !            19: by the Hurd project, the GNU Project, the FSF, the University of Utah, or
        !            20: Major League Baseball.  I just decided this would be a fun thing to do.
        !            21: 
        !            22: For the time being, this is most definitely for kernel hackers and
        !            23: dedicated "thrill seekers" only.  If anything or everything in this message
        !            24: makes no sense to you, then please just don't worry about it.  Just wait,
        !            25: and people to whom it does make sense will decide if and when you want to
        !            26: worry about it and give you specific instructions on where to go and what
        !            27: to do at that time.
        !            28: 
        !            29: This variant is intended to be completely identical to GNUmach from the
        !            30: user-mode perspective (aside from the behavior of the device drivers), and
        !            31: I intend to keep Oskit-Mach abreast of all applicable changes to GNUmach on
        !            32: a regular basis (not much is changed from GNUmach aside from the drivers).
        !            33: 
        !            34: 
        !            35: In some respects this project brings the relationship of Mach and the OSKit
        !            36: full circle.  When maintenance of Mach 3.0 at CMU waned, the University of
        !            37: Utah's Flux Group took over in the form of the Mach4 project, and revamped
        !            38: much of the i386 machine support code in the course of their research.
        !            39: While at Columbia University, Shantanu Goel worked on using Linux device
        !            40: drivers in Mach, and later continued this work at the University of Utah.
        !            41: Utah Mach4 became the seat of Mach development on the 3.0-compatible line,
        !            42: and the microkernel underyling the GNU/Hurd multiserver operating system.
        !            43: When the Flux Group's research moved on from Mach to other systems, they
        !            44: wanted to reuse the work they had done in hardware support and device
        !            45: drivers; this work (and a whole lot more) eventually evolved into the
        !            46: OSKit.  Meanwhile, when the Flux Group stopped maintaining Mach4, the Free
        !            47: Software Foundation's GNU Hurd Project had taken it up and produced the
        !            48: GNUmach release to go with the Hurd.  Since then, the Hurd has become an
        !            49: all-volunteer project whose developers are not paid by the FSF, and later
        !            50: GNUmach releases incorporating bug fixes and updating the Goel/Utah
        !            51: encapsulation of Linux device drivers have been made by volunteers
        !            52: including Okuji Yoshinori and Thomas Bushnell.
        !            53: 
        !            54: This bit of history explains some of why it was so easy to replace a lot of
        !            55: the GNUmach/Mach4 hardware support code with OSKit calls--in many cases the
        !            56: OSKit code is a direct evolution of the code originally in Mach4 that I was
        !            57: replacing, with the names changed and improvements Utah has made since the
        !            58: Mach4 days.
        !            59: 
        !            60: 
        !            61: * What you get vs GNUmach
        !            62: 
        !            63: ** All the benefits of an OSKit kernel
        !            64:   -> Device drivers from Linux 2.2.12 (IDE, SCSI, and Ethernet)
        !            65:      (GNUmach has Linux 2.0.36 drivers with a few fixes.)
        !            66:   -> Serial-port console support with a very simple minimal serial driver
        !            67:   -> OSKit-style Multiboot support, including "return address" hack
        !            68:      for extra-speedy soft reboot when using OSKit's Netboot
        !            69:   -> Serial-port GDB support for debugging the microkernel in style
        !            70:   -> The University of Utah might maintain the device drivers for you
        !            71: 
        !            72: ** A much smaller source tree!  The unpacked OSKit-Mach sources total about
        !            73:    a quarter of the GNUmach sources (though the OSKit itself is much larger
        !            74:    of course).  The gzip'd tar file of the source tree is about 700k, vs
        !            75:    3.6MB for gnumach.  This is because I have wiped out much old cruft, as
        !            76:    well as all the old device drivers and the Linux code.
        !            77: 
        !            78: 
        !            79: * What you lose vs GNUmach
        !            80: 
        !            81: ** All the old device drivers are gone, so you only get what the OSKit has.
        !            82:    It would not be very hard to support some of the old drivers alongside
        !            83:    the OSKit drivers, but I am not interested in working on that.  I am
        !            84:    more interested in adding good new drivers to the OSKit.
        !            85: *** The PC screen/keyboard console driver is very minimal, and not
        !            86:     compatible with the old Mach driver's terminal emulation.
        !            87:     The OSKit's PC console emulates an adm3a terminal, and the keyboard
        !            88:     input support is very simple.
        !            89: *** No real serial drivers at all
        !            90:     The serial drivers that provide the serial console and serial GDB
        !            91:     are very minimal and not really generally usable serial drivers at all.
        !            92:     The oskit's freebsd serial driver might work, but the interface glue
        !            93:     for features specific to serial ports (baud rate, modem control, etc)
        !            94:     is not there.
        !            95: *** No parallel (printer) port driver(?)
        !            96:     The oskit's freebsd printer driver might work.
        !            97: *** No real drivers for PC keyboard or PS/2 mouse at all.
        !            98:     The oskit needs a good clean driver for the low-level keyboard access.
        !            99: 
        !           100: ** No DDB.  I ripped it out rather than making it work.  Serial GDB is much
        !           101:    better.  It might be useful at some point to resurrect some of DDB's
        !           102:    code that prints out kernel data structures in comprehensible form.
        !           103: 
        !           104: * What the hell is the OSKit again?
        !           105: 
        !           106: See <URL:http://www.cs.utah.edu/flux/oskit> to learn all about the OSKit.
        !           107: Please don't ask me to tell you all about it, because I won't do it.
        !           108: 
        !           109: * Where to get it
        !           110: 
        !           111: The source is in the Hurd project's CVS repository as a branch of gnumach.
        !           112: This is available for anonymous CVS from the GNU Project's server.
        !           113: See <URL:http://www.gnu.org/software/devel> about using anonymous CVS.
        !           114: You want to check out the gnumach module with the tag `oskit-branch', i.e.:
        !           115: 
        !           116: cvs -d :pserver:[email protected]:/gd/gnu/anoncvsroot co -d oskit-mach -r oskit-branch -P gnumach
        !           117: 
        !           118: I don't expect to do much in the way of distributing this other than by
        !           119: anonymous CVS any time soon, until it is ready for some kind of release.
        !           120: As I said, at this stage this is for seasoned kernel hackers and masochists
        !           121: only, so I will presume anonymous CVS is something you can cope with.
        !           122: Since cvs is a bit of a bear for the first checkout, I've put together a
        !           123: tar file containing a checkout from anonymous CVS (complete with CVS
        !           124: directories) to get you started.  You can find it at
        !           125: <URL:ftp://ftp.ai.mit.edu/pub/users/roland/mach/oskit-mach-19991125.tar.gz>.
        !           126: 
        !           127: 
        !           128: * What you need to build OSKit-Mach
        !           129: 
        !           130: The build is just the same as GNUmach, except that first you will need to
        !           131: build and install the OSKit.  You need the 19991124 "Butterball" snapshot
        !           132: release of the OSKit, which is at
        !           133: <URL:ftp://flux.cs.utah.edu/flux/oskit/oskit-19991124.tar.gz> (or a later
        !           134: version).  See <URL:http://www.cs.utah.edu/flux/oskit> for more information
        !           135: about the OSKit, including its mailing list and archives (where that
        !           136: wildman Okuji had already posted fixes before the sun set on that
        !           137: snapshot's first day!).
        !           138: 
        !           139: Please don't ask me about building the OSKit; see the web site and the
        !           140: documentation included with the source about what to do and to whom to
        !           141: complain.  (And realize that this is an informal bleeding-edge snapshot,
        !           142: not a released OSKit version, so you should expect to try to figure out
        !           143: your own problems.)  Before you try to build OSKit-Mach, please test your
        !           144: OSKit build on your hardware by building and running some of the oskit's
        !           145: example programs and making sure they boot and run ok.
        !           146: 
        !           147: The only way that I've actually built oskit-mach is with my i486-gnu (Hurd)
        !           148: cross-compilation setup; I just built the oskit with that cross-compiler
        !           149: and --prefix=/usr/i486-gnu and installed it.  Then just configure
        !           150: oskit-mach normally and build.  All of this should work with any native
        !           151: ELF/x86 compiler too (and no --prefix).  It should probably work to
        !           152: configure oskit-mach using the oskit's compiler front-end (i386-oskit-gcc),
        !           153: but I haven't tried that and don't recommend it.  The only difference
        !           154: between using a native compiler or a cross-compilation setup that has glibc
        !           155: installed, and using i386-oskit-gcc, should be that a few functions such as
        !           156: memcpy will come from the oskit's minimal C library rather than from glibc,
        !           157: which has much better-optimized implementations of those
        !           158: performance-critical functions.
        !           159: 
        !           160: 
        !           161: * If you are a rabid Mach kernel hacker
        !           162: 
        !           163: There are a few things to mention about technical details of how I did some
        !           164: things, and I will write some notes up sometime soon and stick them in the
        !           165: sources someplace.  In the meantime, there are some comments and if you
        !           166: grok the kernel already then reading the code should be substantially
        !           167: self-explanatory.  Aside from removed files, the diffs between the gnumach
        !           168: trunk and the oskit-branch are fairly small (cvs is your friend); all the
        !           169: new oskit-related support code is in the new oskit/ subdirectory.
        !           170: 
        !           171: 
        !           172: Please send bug reports to <[email protected]>.  If you have a problem with
        !           173: device drivers, before you report it to me as a problem with OSKit-Mach,
        !           174: please try those drivers on your hardware using some oskit example kernels.
        !           175: If your problems show up using those device drivers on your hardware in an
        !           176: oskit example kernel, then please report it to <[email protected]> as
        !           177: an oskit problem rather than reporting it as Mach problem.
        !           178: 
        !           179: 
        !           180: Enjoy,
        !           181: Roland McGrath <[email protected]>

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