When the kernel is present in memory, the sequence on an ARM processor based system is similar to what might happen on a desktop computer. However, the bootloading process can be very different, as ARM processor based phones or more deeply embedded devices can lack a hard drive or PC-like BIOS.

Typically, what happens when you power the system on is that hardware specific boot code runs from flash or ROM. This code initializes the system, including any necessary hardware peripheral code and then launches the bootloader (for example U-Boot). This initializes main memory and copies the compressed Linux kernel image into main memory (from a flash device, memory on a board, MMC, host PC or elsewhere). The bootloader passes certain initialization parameters to the kernel. The Linux kernel then decompresses itself and initializes its data structures and running user processes, before starting the command shell environment. Let's take a more detailed look at each of those processes.