Hi all,

there is a (still) small group ('cuby' and myself) starting to work on porting the Apple Darwin Microkernel (also called XNU) to the Sharp Zaurus. The ideas behind are

* provide a BSD compatible real microkernel
* learn something
* a microkernel is something the Embedded World might look for (especially interesting for single-processor mobile phones)
* Darwin is very robust
* Development tools are for free (well, you need a Mac and a Zaurus - but development can be done using free Xcode & gcc)

So, if you are interested, please have a look at a first description page I have put on my server. And there is a forum for further technical discussions. It already contains some materials on how to create a gcc-3.4.2 cross compiler, the Mach-O format, what Darwin is, and how it works internally.

Here are the links:
http://www.dsitri.de/wiki.php?page=Darwin%20on%20ARM
http://www.dsitri.de/phpBB2/viewforum.php?f=24

-- hns

Interesting. You have a huge amount of work laying before you. Good luck in your efforts!

Thanks for the wishes!

And as usual it mainly depends on contributing people - like you have surely experienced with the OE/OZ projects...

There *might* be some aspects both projects could share like knowledge about hardware details and driver code although I know that Darwin and Linux are *very* different in their internal structures. And although both are based on *NIX and GCC there isn't very much in common.

The main work is expected in making the device drivers (.kext kernel extensions) fit to the Zaurus hardware. But the good thing is that they can be written in C++ using the IOKit.

The second largest part is probably adapting the XNU sources to compile for the ARM CPU including the hardware dependent parts of the Mach kernel. This needs some assemler and understanding how to map the primitives to interrupts, memory management etc. and make it booting.

And the smallest issue is to get the most recent GCC cross compiler to generate Mach-O binaries for the ARM architecture.

So if anybody (or any-company) wants to support or knows somebody (or some-company) who can help, please let us know.

-- hns

PS: the best soultion would have been if IBM had continued their PowerPC 405LP based PDA...