Subject: Re: Making UFS optional
To: Wolfgang Solfrank <>
From: Chris G. Demetriou <cgd@postgres.Berkeley.EDU>
List: tech-kern
Date: 03/03/1994 19:40:03
>In an attempt to stir up some more user complaints of the type "my kernel
>doesn't build any more" :-), I'm going to make ufs (more or less) optional.

sounds like a good idea...  it should be "options FFS" for future
compatibility.  8-)

>This means, moving quite some code out of the ufs directory.


>And then there is the file ufs_disksubr.c, which hasn't anything to do with
>ufs at all. It contains code that is used by most (if not all) disk drivers.
>I'm not sure where to place this file.
>Should it go into the kern directory and made optional on all the disk drivers
>(needs inclusion of this file in all the machine dependent
>configuration files and editing this files in non-obvious places, when a new
>driver is added), made standard (superfluous inclusion of code for diskless
>machines) or placed into libkern (my preference, but up until now libkern
>only includes routines that (re-)implement things that are also available
>in user mode.

hmm.  it would make the most sense to put it into libkern, given the
problem with figuring out when it gets included...

Perhaps it's appropriate to split libkern (e.g. via a subdir) into
"libc-derived code" and "kernel code."