Here's how to Setup a Development toolchain for cross-compiling code for SlugOS (based on http://wiki.openmoko.org/wiki/Toolchain#Installing_New_Libraries(approve sites))

• Build Toolchain

        make update
        bb meta-toolchain-slugos

• extract resulting tar file (found in slugos/deploy/sdk) to root (to get /usr/local/slugos)

        tar jxvf slugos-5.4-alpha-armv5te-linux-gnueabi-toolchain-slugos.tar.bz2 -C /

• Setup environment (this has to be done every session)

        source /usr/local/slugos/armeb/environment-setup

• Configure toolchain's opkg with appropriate cross feeds URL (for opkg-target to fetch packages)

        vi /usr/local/slugos/armeb/armeb-linux-gnueabi/etc/opkg.conf
        (ie. replace '/all' with 
        http://ipkg.nslu2-linux.org/feeds/slugosbe/cross/5.3-beta/)

• Update package list

        opkg-target update

• Add required packages to toolchain (-dev is for includes)

        examples:
        opkg-target install libusb-1.0
        opkg-target install libusb-1.0-dev
        opkg-target install gpsd
        opkg-target install gpsd-dev

• Update project's Makefile to use pkg-config in LDFLAGS and CXXFLAGS

        ie. `pkg-config --libs libusb-1.0` & `pkg-config --cflags libusb-1.0`

• Build your project

        make