On Tue, 13 Feb 2001, Allen Briggs wrote:

> On Tue, Feb 13, 2001 at 05:07:45PM -0800, Henry B. Hotz wrote:
> > >Anyone interested in trying to get the Darwin HFS support working, BTW?
> > Is that allowed by the Darwin license?  Or do you mean use the Darwin 
> > source as a reference to create our own?
> 
> I'm not sure--I was under the impression that the Darwin code was under
> at least some sort of "open source" license.  That should at least allow
> someone to create an LKM filesystem that could be a separate package.

It's open-source, except changes have to be fed back to Apple, and they
have to be able to use them as they wish. It's a mix of GPL and BSD. It
lacks the object-contamination aspects of GPL. Segregating it to its own
tree, adding Readme's, and maybe a on-change-email-Apple cvs commit script
would more than satisfy things. Oh, there'd need to be a big README for
folks who use the code in other products..

I looked at the code, and got overwhelmed. I can see the ancestry in the
VFS system, but it was a bear to deal with.

One big problem is that they introduced a new vnode type, named Complex I
think. It's a vnode which represents the whole file (both forks). It is an
interesting mix of file and directory. You can do name lookups to ask for
particular forks (data or resource), but you can also do reads and get the
underlying file data. I haven't figured out how to do vnode locking for
this...

> It might also be useful as a reference, though, for a native driver.

That it would. But there is a certain beauty in being bug-compatible with
Apple. :-)

Take care,

Bill