Subject: Re: UDF project status update
To: None <tech-kern@netbsd.org>
From: Christos Zoulas <christos@tac.gw.com>
List: tech-kern
Date: 04/17/2005 20:39:00
In article <20050417224407.GB25928@rangerover.13thmonkey.org>,
Reinoud Zandijk  <reinoud@netbsd.org> wrote:
>-=-=-=-=-=-
>
>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 
>opensource.
>
>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.
>

Still since your code does not have a kernel portion, why not start with
the FreeBSD one? Unless their version is flawed in some way that you have
not mentioned.

christos