Subject: Re: Multiple linux /emul environments
To: Christos Zoulas <christos@zoulas.com>
From: David Brownlee <abs@anim.dreamworks.com>
List: tech-kern
Date: 02/21/1999 23:53:05
On Sun, 21 Feb 1999, Christos Zoulas wrote:

> In article <Pine.GSO.4.05.9902191304040.16700-100000@cynic.anim.dreamworks.com> abs@anim.dreamworks.com (David Brownlee) writes:
> >	What we need is some way to tell the kernel that certain linux
> >	binaries do not use /emul/linux.
> >
> >	Trying to generalise this, would it make sense to allow binaries
> >	to be tagged (possibly via an elf note) to run with different
> >	/emul/XXXX paths? Maybe based on the Vendor-specific ELF note
> >	docs as at www.netbsd.org/Documentation/kernel/elf-notes.html
>
> If you are running /current you can make the binary only look in the
> real tree (and not in /emul) by prefixing the path with /..
> 
> For example if /emul/linux/lib exists, a linux program accessing /lib
> will actually reference /emul/linux/lib, but if it accesses /../lib
> it will reference the real /lib.

	This does not work for us - specifying the filesystems as
	/../ and /../usr/ leaves the client ignoring all files.
	Had it worked it would have been an interesting sell to other
	people around here ("So I have to add '/..' to the start of every
	path when I backup or restore on the NetBSD boxes?"), but it
	looks like a non-starter :/

	I could change the magic number on the ADSM binary and setup a
	different (empty) /emul filesystem, but I'd prefer to come up with
	a generally useful (and clean :) solution...
	
		David/absolute

                  -=-  and team B will be... Kenny.  -=-