An initramfs is a kernel with an include filesystem that can be use directly from uboot with clunc. You can use miniroot or buildroot to build an initramfs.

Miniroot is intended to be a simple solution to build and/or develop a minimal system based on Linux and BusyBox. The system is “makefile-oriented” with few shell scripts. Its main goal is to be human readable.

The project is available on git :

  git clone git://lacie-nas.org/miniroot.git    

Customisations are done by writing your own config.mk (see doc/ directory).

The list of relevant variables can be found in headers of .mk files or in the main Makefile.

Buildroot is a set of Makefiles that makes it easy to generate a complete Linux system. Buildroot is a project quite bigger than miniroot but have higher capabilities.

The project is available on :

   http://buildroot.uclibc.org/

Buildroot has a nice configuration tool similar to the one you can find in the Linux kernel. The configuration assistant can be run with :

   make menuconfig