Subject: Re: UDF project status update
To: None <>
From: Reinoud Zandijk <>
List: tech-kern
Date: 04/18/2005 00:44:07
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

Hiya Hubert,

On Sun, Apr 17, 2005 at 11:54:34PM +0200, Hubert Feyrer wrote:
> On Sun, 17 Apr 2005, Reinoud Zandijk wrote:
> >My strategy is still to develop the UDF support using a two-track system;
> Why reinvent the wheel and not use the FreeBSD/OpenBSD version?

Simple reasons: the FreeBSD/OpenBSD version is pretty limited; its 
*read-only* and only supports a subset of UDF just enough to read Roxio 
DirectCD discs and prolly also Nero InCD.

No support for writing has ever been envisoned by the author of the FreeBSD 
code and its code has been in this state for a couple of years. In my talks 
with him he said he wasn't working on any enhancement either. UDF however 
is not standing still and allthough the FreeBSD/OpenBSD version now also 
reads UDF 2.01 the standard is allready at 2.60 introducing quite a lot. 
The FreeBSD/OpenBSD version is well written but has some limits on the UDF 
filingsystems it can grock. Silicon graphics is known to have used the 
FreeBSD framework as a starting point for their read/write implementation 
of UDF in Irix but offcoure (...) didn't contribute the code back to 

My version doesn't read 2.50 and 2.60 either yet but has all the nessisary 
bolts and plates allready to fix that on though. The kernel version was set 
back some time by some unclear in-kernel SCSI ioctl() issues allready 
discussed on either this list or on tech-kern wich are solved now. The 
version i am working on is in a way a bit `overdone' i have to admit; it 
support a bit too much and ever is pretty relaxed in what 
versions/recording programs it can handle. I haven't encountered an UDF 
disc yet that it couldn't read nor write but then again the UDF standard 
can be quite elaborate.

In the end i hope to come up with a inkernel implementation of UDF that can 
both read and write on both recordable and rewritable media. Restricted / 
self remapping overwrite media like BluRay 'DVD' are also to be supported.

Hope this answers enough for now,


Content-Type: application/pgp-signature
Content-Disposition: inline

Version: GnuPG v1.2.6 (NetBSD)