Emdebian rootfs for Emdebian Crush

The root filesystem is a basic set of packages needed to provide a usable login environment around a kernel and kernel modules. The rootfs must be extensible to a full system so normal packaging tools need to be supported. See also Emdebian website.

The main Debian root filesystem is based on 'Essential' - a collection of packages that contain: Essential: yes in debian/control and although small in Debian terms, it is still much too large for Emdebian.

This page concentrates on how to use the emdebian-rootfs package to build an Emdebian root filesystem for your device and describes how to customize your package set for your needs.

Linux Embedded

In order to be able to build an embedded Linux system, obviously you need:

The GNU cross-development tools installed on your host machine (presumably a Linux PC machine).

Your target system will need to have these different pieces of software:

Firmware (or boot loader), such as u-boot, redboot or a BIOS: you can these choose to boot from Flash, network (tftp), or disk;

Kernel (linux): the kernel must be compiled with support for your board (cpu and peripherals);

Root file system (contains the C/C++ libraries, the shell, etc.).

If your board comes with a ‘good’ firmware, you might not need at all a JTAG programmer. Using the firmware, you might be able to program the flash with the kernel and/or the root filesystem. Both u-boot and redboot let you do this, assuming they have the drive for the Flash you are using.