RPi２開機順序與相關檔案

根據資料，RPi是把bootloader利用GPU執行的

在 https://github.com/raspberrypi/firmware
裡面提到

*start.elf, bootcode.bin are the GPU firmware and bootloaders. 

Their licence is described in 'LICENCE.broadcom'.

The kernel.img files
  are builds of the Linux kernel, released under the GPL (see COPYING.linux)