configure busybox

[Glenn McGrath]

Hi, im trying to make a project im involved with
(http://busybox.lineo.com/) more portable, specifically i want to make it
compile under GNU/Hurd as well as linux.

My initial thoughts were that autotools would be ideal, but busybox is an
unusal project and im unsure how to go about it.

Busybox is a single binary that can provide the funcionality of one of
about 130 (i think) general unix commands.

Current build process goes roughly as follows, there is a manually edited
config file (Config.h, not to be confused with the autotools config.h) that
defines which ./<command>.c files are compiled. There is also a library of
common functions (./libbb/libbb.a) that are all compiled and linked to
irrespective of which commands are wanted.

The problems i see are;

1) all libbb files are compiled, however some have system calls that
obviously depend on the linux kernel (and other portability problems),
there needs to be a way to only compile functions that will work on the
target machine.

2) Config.h assumes that libbb is fully functional and therefore any of the
commands will compile, however functions that may be required to compile a
specific command may not have been compiled in libbb and may be missing. It
would be good if a Config.h could be generated  that only lists commands
that are compilable, then the user could manually select what they want
(and will work) prior to making it.

Is it a bit ambitious to expect autotools to be able to handle this sort of
setup, in the short term its probably easier to manually port/fork busybox
to another architecture, but the best longterm solution would be if
autotools could be made to handle it.

Does anyone have any advice, or examples of similarly situations in other
projects ?

(Ive only used autotools on simple projects)


Thanks

Glenn