Embedded Linux system basis

An embedded Linux system is very similar (when speaking about software) to a Desktop one, thanks to the power of the latest embedded microprocessor, like the ARM9 one. It is composed of:

• a bootloader, which is the first bits of code executed when the processor starts. It behaves like the BIOS+Grub combination on Desktop PCs.
• an operating system = the Linux kernel
• many programs and librairies organised in a filesystem = the rootfs

The bootloader

In our case our bootloader is U-Boot. It's main role is to initialize the hardware, load the Linux kernel and launch it with the correct parameters

The kernel

In our case Linux.

The rootfs

It is composed of:

• a C library
• basic utilities (in our case regrouped as one executable through Busybox)
• additionnal librairies and tools

To build all these tools, you need a "build system". We use Buildroot.