Using buildroot with the Code Sourcery toolchain to produce a uClibc based file system for uclinux

Code Sourcery
uClibc
Uclinux for linux programmers
buildroot

Process

Take the following steps to produce a minimal, static linked, flat binary file system.
The process below was carried out using buildroot revision 20649
with the Code Sourcery toolchain

arm-uclinuxeabi-gcc (CodeSourcery Sourcery G++ Lite 2007q1-21) 4.2.0 20070413 (prerelease)

• svn co svn://uclibc.org/trunk/buildroot
• Unpack the Code Sourcery uclinuxeabi toolchain.
• Patch buildroot as per patch attached
  Note that the patch contains a full busybox config file...
• Adjust for changes since my build....
• Setup the environment as in the attached script.
• Copy in the attached .config
• Adjust for your environment - at least
  • Location of the CS toolset
• (?sudo?) make oldconfig
• (?sudo?) make PREFERRED_LIB_FLAGS="--enable-static --disable-shared" PMP_MY_REAL_CROSS_GCC=<The Code Sourcery cross compiler>
• Adjust for changes since my build....

You'll need to twiddle the startup scripts in the resulting file system for your platform.
Make, stderr and boot log attached
I've only booted - not checked every binary runs
Please report bugs to mailto:peter.pearse@arm.com with Wiki [uClibc] in the subject

Retry with buildroot 20854

• package/fakeroot.mk and package/fakeroot-uclibc-LFS.patch are now patched in the buildroot tree.
• busybox has gone up to 1.9
  • Move the patches up where necessary
    transormer no longer required, others apply with offset.
• Kernel, GNU, Debian mirrors added - accepted defaults

Thumb-2

• Just add the gcc options as in the comment in the setup file.

TODO (not in order)

• Implement dynamic linking for flat binaries - I believe this needs both kernel and file system work....
• Add more packages
• Perfect the patch - still some generated files & binaries in it
• Actually run some of the binaries

Detailed explanation of (some of) the patches

• Stripping gave some problems so I turned it off throughout
• -Dfork=vfork worked in most packages, but I had to patch some headers to stop them failing e.g. busybox/libbb.h
• Some packages needed really hammering to build static libraries
  • Maintainers - please don't use .so files as targets if your package can be built statically.....
• Of course, some package versions changed
• Some packages had to be apprised of the existence of uclinux (altho I haven't checked that they work with it!)
• ARM still hasn't caught up with syscall()
• Some packages initialize their flags
  - I think it's nicer if the append to the environment values, rather than losing them.

-- PeterPearse - 13 Dec 2007