xref: /freebsd/rescue/README (revision a2f733abcff64628b7771a47089628b7327a88bd)
1The /rescue build system here has three goals:
2
31) Produce a reliable standalone set of /rescue tools.
4
5The contents of /rescue are all statically linked and do not depend on
6anything in /bin or /sbin.  In particular, they'll continue to
7function even if you've hosed your dynamic /bin and /sbin.  For
8example, note that /rescue/mount runs /rescue/mount_nfs and not
9/sbin/mount_nfs.  This is more subtle than it looks.
10
11As an added bonus, /rescue is fairly small (thanks to crunchgen) and
12includes a number of tools (such as gzip, bzip2, vi) that are not
13normally found in /bin and /sbin.
14
152) Demonstrate robust use of crunchgen.
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17These Makefiles recompile each of the crunchgen components and include
18support for overriding specific library entries.  Such techniques
19should be useful elsewhere.
20
213) Produce a toolkit suitable for small distributions.
22
23Install /rescue on a CD or CompactFlash disk, and symlink /bin and
24/sbin to /rescue to produce a small and fairly complete FreeBSD
25system.
26
27These tools have one big disadvantage: being statically linked, they
28cannot use some advanced library functions that rely on dynamic
29linking.  In particular, nsswitch, locales, and pam all
30rely on dynamic linking.
31
32
33To compile:
34
35# cd /usr/src/rescue
36# make obj
37# make
38# make install
39
40Note that rebuilds don't always work correctly; if you run into
41trouble, try 'make clean' before recompiling.
42