>Date: Sun, 17 Dec 1995 20:09:27 -0800
>From: Jonathan Stone <jonathan@dsg.stanford.edu>

>To build kernels, /usr/src/sys/arch/compile/ needs to have a read-write
>filesystem mounted on it.

We could replace each /usr/src/sys/arch/*/compile directory with a
symlink to /usr/obj/sys/arch/*/compile, instead.  Each
/usr/src/sys/arch/*/Makefile would need an obj: target to create the
link.

>I haven't found that to be a limitation.  If it's a limitation for
>others, then I think the "read-only" status is a side issue; the
>scheme above would, for example, allow compiling from source on a
>CD-ROM (provided of course the ./obj symlinks were on the CD-ROM).

The Walnut Creek 4.4BSD CDROM that I have has obj links and tags
files in each directory.

>If what Gary is really after is building multiple object trees, on
>a single machine, from a single source tree, then "lndir" is one
>ugly, but time-worn, solution.

Note that X11R6 renamed lndir to something else, I forget what
exactly.
-- 
Mike Long <mike.long@analog.com>           http://www.shore.net/~mikel
VLSI Design Engineer         finger mikel@shore.net for PGP public key
Analog Devices, CPD Division          CCBF225E7D3F7ECB2C8F7ABB15D9BE7B
Norwood, MA 02062 USA       (eq (opinion 'ADI) (opinion 'mike)) -> nil