Maybe this information is of use to someone, so I'll write it down. Maybe it has been mentioned elsewhere already, but you'll have to forgive me then. Better an abundance of information than a shortage, eh?
- Download the latest version of the iPKG tools from ftp://ftp.handhelds.org/packages/ipkg-utils/ (version 1.7 seems to be the latest);
- untar the archive, cd into the just untarred directory, and type 'make install' (make sure you're root);
- open /usr/local/bin/ipkg-build, find the line where it says "outer=ar" (line 159 in version 1.7), and change "ar" into "tar";
That sets up your build environment. From here on it's pretty straightforward. To create a package copy everything you want in it into a directory, in the directorystructure it needs to be on the target device. Also, you need to create a control file with some meta data about the package, and it has to live in the CONTROL directory. e.g. Say I have a binary, foo, and I need it to be available as /bin/foo on the target device. The procedure would be something like this:
mkdir -p /tmp/foo/bin cp foo /tmp/foo/bin mkdir -p /tmp/foo/CONTROL cat >/tmp/foo/CONTROL/control <<EOF Package: foo Version: 0.1 Architecture: mipsel Maintainer: foo bar <firstname.lastname@example.org> Section: base Priority: optional Description: This package provides foo, which does nothing. Source: http://foo.bar/foo EOF ipkg-build -o root -g root /tmp/foo /tmp
The result will be a package /tmp/foo-0.1_mipsel.ipk, which is ready to install on a standard openwrt distribution.
If modifying your ipkg environment is not an option, there's the possibility to modify your openwrt installation.
A standard ipkg-build produces packages which are basically two tarballs put together with "ar". In a standard openwrt, busybox is compiled without support for "ar", so to use standard iPKG packages in openwrt this has to be compiled back in. Modify buildroot/sources/busybox.config to include "CONFIG_AR=y" (line 39). Then modify buildroot/build_mipsel/root/bin/ipkg to use "ar" for extracting ipkg files (line 729, change "tar" into "ar -p", just like 2 lines below it). Possibly also a symlink has to be made to busybox for ar, so while you're in buildroot/build_mipsel/root/bin/ anyway, type "ln -s busybox ar". Rebuild your openwrt image, and it *should* support standard iPKG packages now...well, except for the ones which were already created for openwrt :-)
Chicken, egg, time to make a decision on whether or not to support standard iPKGs?
That's all for now, more to follow as I progress. Happy packaging.