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rtmk - real-time microkernel

This is rtmk, a free real-time microkernel released under the GNU General Public License version 2 or later.

About rtmk

rtmk is free real-time microkernel developed by Johan Rydberg. It shared alot of ideas with the Mach microkernel developed by CMU in the late 80's and early 90's (project stopped in -94).

The goals for the project;

create a fast and stable microkernel,
implement a single server operating system using the kernel, and
getting the Hurd running on the microkernel.

Current status of the kernel:

Working things:

Preemptive, fully re-entrant, multithreaded kernel
Callouts (done, partly verified)
Full locking primitives (read/write, sleep, recursive, ...)
Priority lending (done, partly verified)
Multiprocessor support (SMP) (partly done, partly verified)
Migrating threads (done, partly tested)
Interrupt threads (done, partly tested)
Copy-on-write and read-write shared memory (partly tested)

Not working/implemented things:

Continuations
...

See the Work-In-Process section to find out what I'm currently working on.

News

...
March 27, 2002: At last, a new source snapshot. This snapshot is the first one with RIG as a separate module. Also included is a pthread library.
March 22, 2002: No news really. I'm currently working on the new version of RIG. I also have rewritten huge parts of the IPC system.
February 16, 2002: James Jacobsson was kind enough to make a binary dist of the rtmk cross-compiler toolchain available to the rest of us. This dist contains GCC 3.0.1, GNU binutils 2.11.2 and the GNU C library version 2.2.4. Just untar it in your root directory, and add "/rtmk/bin" to your path. If you wanna do it your self, take a look here.
February 1, 2002: Add the Documentation section.
January 23, 2002: Got the GNU C library somewhat working, and here's small screenshot.
January 21, 2002: I have decided to not distribute any C library with the kernel. It is up to the operating system to supply one. Two library will be supplied by rtmk though; librtmk and libpthread.
January 17, 2002: Wrote a small introduction document to the new version of RIG.
January 12, 2002: New source snapshot. See Obtaining rtmk.
January 5, 2002: New source snapshot. See Obtaining rtmk.
December 19, 2001: Wrote a small text describing the features of rtmk.
December 7, 2001: Also released a source snapshot of today. See Obtaining rtmk for more info.
December 7, 2001: CVS and mailing lists moved to Savannah

Documentation

The rtmk manual is available in the following formats:

formatted in HTML (33K) entirely on one web page.
formatted as a PDF file (134K characters).
formatted as a PostScript file (158K characters gzipped).

Work-In-Progress

Well, I work on lots of things. I suggest that you look at the rtmk-cvs archives.

Obtaining rtmk

The latest source snapshot of rtmk is 20020327 (mirror). The NEWS file has details of what's changed in this release.

If you plan to do active work on the rtmk, you can access the development source tree by anonymous CVS:

  cvs -d:pserver:anoncvs@subversions.gnu.org:/cvsroot/rtmk login 
  {just hit enter when prompted for password}
  cvs -z3 -d:pserver:anoncvs@subversions.gnu.org:/cvsroot/rtmk co rtmk

Available modules are: rtmk, rig and pthread. Alternatively, you can use the viewcvs interface.

Contact

There are some public mailing lists related to rtmk.

rtmk-discuss (archives): For discussing rtmk issues
rtmk-cvs (archives): A read-only mailing list containing the notes from checkins to the rtmk CVS

You can also drop in at the #rtmk or #osdev IRC channels at irc.openprojects.net

Frequently Asked Questions

What about the PowerPC port? What hardware is supported? Currently the PowerPC port can only be run within the PSIM simulator. The PowerPC port was mainly done to make it easier to debug and profile the kernel.: Currently the PowerPC port can only be run within the PSIM simulator. The PowerPC port was mainly done to make it easier to debug and profile the kernel.

Contributing

Help is always needed. Among the things that need to be done (that I would like some help with) is:

Writing a bootloader for the PPC port, that can load the kernel and multiple modules from a ext2 and/or HFS file system.
Generic help with the PPC port.
And of course other stuff that needs to be done.