File.........: 5 - Using the toolchain.txt Copyrigth....: (C) 2010 Yann E. MORIN License......: Creative Commons Attribution Share Alike (CC-by-sa), v2.5 Using the toolchain / ____________________/ Using the toolchain is as simple as adding the toolchain's bin directory in your PATH, such as: export PATH="${PATH}:/your/toolchain/path/bin" and then using the target tuple to tell the build systems to use your toolchain: ./configure --target=your-target-tuple or make CC=your-target-tuple-gcc or make CROSS_COMPILE=your-target-tuple- and so on... It is strongly advised not to use the toolchain sysroot directory as an install directory for your programs/packages. If you do so, you will not be able to use your toolchain for another project. It is even strongly advised that your toolchain is chmod-ed to read-only once successfully build, so that you don't go polluting your toolchain with your programs/packages' files. Thus, when you build a program/package, install it in a separate directory, eg. /your/root. This directory is the /image/ of what would be in the root file system of your target, and will contain all that your programs/packages have installed. The 'populate' script | ----------------------+ When your root directory is ready, it is still missing some important bits: the toolchain's libraries. To populate your root directory with those libs, just run: your-target-tuple-populate -s /your/root -d /your/root-populated This will copy /your/root into /your/root-populated, and put the needed and only the needed libraries there. Thus you don't polute /your/root with any cruft that would no longer be needed should you have to remove stuff. /your/root always contains only those things you install in it. You can then use /your/root-populated to build up your file system image, a tarball, or to NFS-mount it from your target, or whatever you need. The populate script accepts the following options: -s src_dir Use 'src_dir' as the un-populated root directory. -d dst_dir Put the populated root directory in 'dst_dir'. -l lib1 [...] Always add specified libraries. -L file Always add libraries listed in 'file'. -f Remove 'dst_dir' if it previously existed; continue even if any library specified with -l or -L is missing. -v Be verbose, and tell what's going on (you can see exactly where libs are coming from). -h Print the help. See 'your-target-tuple-populate -h' for more information on the options. Here is how populate works: 1) performs some sanity checks: - src_dir and dst_dir are specified - src_dir exists - unless forced, dst_dir does not exist - src_dir != dst_dir 2) copy src_dir to dst_dir 3) add forced libraries to dst_dir - build the list from -l and -L options - get forced libraries from the sysroot (see below for heuristics) - abort on the first missing library, unless -f is specified 4) add all missing libraries to dst_dir - scan dst_dir for every ELF files that are 'executable' or 'shared object' - list the "NEEDED Shared library" fields - check if the library is already in dst_dir/lib or dst_dir/usr/lib - if not, get the library from the sysroot - if it's in sysroot/lib, copy it to dst_dir/lib - if it's in sysroot/usr/lib, copy it to dst_dir/usr/lib - in both cases, use the SONAME of the library to create the file in dst_dir - if it was not found in the sysroot, this is an error.