Re: Urgent help needed to port some drivers on Fiasco L4 µ-Kernel

Björn Döbel doebel at
Fri Apr 3 00:58:41 CEST 2009

Hash: SHA1


>               We are students of IIT Delhi. We are working on a project
> based on Fiasco L4 microkernel. We need to buid servers on L4 for ext2
> filesystem support and usb web cam support. Could you please clear following
> doubts :
>               1) Does "fiasco l4 microkernel/ l4 env" provide support for
> ext2 filesystem or usb webcam ?


The L4Env does not contain a working implementation of an ext2 file
system nor a USB webcam driver (which is actually a pretty vague
description as there are several different webcams, aren't there?).

>               2) Does "fiasco l4 microkernel/ l4 env" provides Device Driver
> API library so that we can build driver for it ?


If you want to build your own device driver, we recommend to use the
DDEKit, a basic device driver API that can be found in l4/pkg/dde/ddekit.

>               3) Do we need to build both usb driver and webcam driver in
> "fiasco l4 microkernel/ l4 env" to provide support for usb webcam ?


If you want to support a USB webcam, you'll need a USB host controller
driver as well as a specific driver for your USB web cam. Dirk Vogt did
an implementation of a HC as well as a USB driver framework and is
currently integrating it into the L4Env. I hope to see it in the public
SVN soon.

>               4) Does "fiasco l4 microkernel/ l4 env" provides l4 io driver
> for SATA or IDE harddisk ? Can we use that to build our ext2 filesystem
> support for it?

We have done some experiments with hard disks. One can be found in
l4/pkg/l4ide. It is an IDE driver that makes use of the (deprecated)
dde_linux26 package. The more recent DDE in l4/pkg/dde/linux26 does
contain most of the necessary stuff to get an IDE driver running.

It should be pretty straightforward to implement an ext2 file system
server similar to the way the Flexible IP Stack (FLIPS - l4/pkg/flips)
was implemented by just taking the necessary files from the Linux kernel
sources and linking them against the necessary Device Driver Environment
(DDE) libraries.

Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla -


More information about the l4-hackers mailing list