freebsd-dev/rescue
Xin LI 9a9ea25f4a Replace the GNU gzip with a slightly modified NetBSD gzip. The
NetBSD version is a feature-to-feature re-implementation of GNU
gzip using the freely-redistributable zlib and this version is
expected to be mostly bug-to-bug compatible with the GNU
implementation.

 - Because this is a piece of mature code and we want to make
   changes so it is added directly rather than importing to
   src/contrib.
 - Connect newly added code to src/usr.bin/ and rescue/rescue
   build.
 - Disconnect the GNU gzip code from build for now, they will
   be eventually removed completely.
 - Provide two new src.conf(5) knobs, WITHOUT_BZIP2_SUPPORT and
   WITHOUT_BZIP2.

Tested by:	kris (full exp-7 pointyhat build)
Approved by:	core (importing a 4-clause BSD licensed file)
Approved by:	re (adding new utility during -HEAD code slush)
2007-01-26 10:19:08 +00:00
..
librescue Respect MK_INET6_SUPPORT. 2006-07-27 12:28:05 +00:00
rescue Replace the GNU gzip with a slightly modified NetBSD gzip. The 2007-01-26 10:19:08 +00:00
Makefile Add /rescue bits. This basically encompasses all of bin and sbin along 2003-06-29 18:35:37 +00:00
README

The /rescue build system here has three goals:

1) Produce a reliable standalone set of /rescue tools.

The contents of /rescue are all statically linked and do not depend on
anything in /bin or /sbin.  In particular, they'll continue to
function even if you've hosed your dynamic /bin and /sbin.  For
example, note that /rescue/mount runs /rescue/mount_nfs and not
/sbin/mount_nfs.  This is more subtle than it looks.

As an added bonus, /rescue is fairly small (thanks to crunchgen) and
includes a number of tools (such as gzip, bzip2, vi) that are not
normally found in /bin and /sbin.

2) Demonstrate robust use of crunchgen.

These Makefiles recompile each of the crunchgen components and include
support for overriding specific library entries.  Such techniques
should be useful elsewhere.  For example, boot floppies could use this
to conditionally compile out features to reduce executable size.

3) Produce a toolkit suitable for small distributions.

Install /rescue on a CD or CompactFlash disk, and symlink /bin and
/sbin to /rescue to produce a small and fairly complete FreeBSD
system.

These tools have one big disadvantage: being statically linked, they
cannot use some advanced library functions that rely on dynamic
linking.  In particular, nsswitch, locales, and pam are likely to all
rely on dynamic linking in the near future.


To compile:

# cd /usr/src/rescue
# make obj
# make
# make install

Note that rebuilds don't always work correctly; if you run into
trouble, try 'make clean' before recompiling.

$FreeBSD$