On Thu, Mar 08, 2007 at 04:13:03PM -0800, Jason Thorpe wrote:
> 
> On Mar 8, 2007, at 3:25 PM, Dieter Baron wrote:
> 
> >my goal is to enhance vnd(4) to support UDIF (Apple's Universal Disk
> >Image Format; the format .dmg files use).  This format compresses
> >chunks (usually 128kb) of the disk, similar to CLOOP2 we already
> >support.  It can use zlib or bzip2, and has support for AES-128
> >encryption.
> 
> OS X, FWIW, has a hybrid approach.  Un-encrypted / un-compressed DMGs  
> are handled entirely in the kernel-resident driver, IIRC, and stuff is  
> only passed to userland if it is necessary to do so.

  Un-encrypted, un-compressed DMGs are just the raw data with a
trailer tacked onto the end.  They work with our current vnd (with the
caveat that the trailer is readable as an additional sector).

					yours,
					dillo