Boot process

This is the sequence that OFW goes through before booting an image. The canonical specification should be at Firmware Security.

1. If all four game-pad buttons are held down (secure copy-nand)
   1. Firmware looks at fs.zip (should be in root directory of usb key, along with the os{build_number}.img)
      • fs.zip should have data.img and data.sig in it
   2. If the data.sig lines up with the data.img, the os{build_number}.img is booted.
2. If your laptop is insecure (the ww flag is set instead of the wp flag)
   • The laptop boots the old insecure way (loads /boot/olpc.fth and runs whatever script is there)
   • NOTE: if you hold the '×' game-pad key during startup, the laptop will go into secure mode for that one boot up
3. If your laptop is secure (wp flag set, or '×' game-pad key was held), then...
   1. If dk flag is set
      • goto old insecure boot
   2. If present and valid /security/develop.sig (in the usb, sd, or nand)
      • goto old insecure boot.
   3. If present /boot/bootfw.zip (for secure reflash of OFW) (has... how should key be set up? data.rom and data.sig?)
      • If signature is valid, then reflash
   4. If present, valid, and not expired /security/lease.sig OR the ak flag is set
      • If present /boot/os.zip (contains data.sig and data.img)
        • then, If data.sig and data.img are valid, boot from the data.img.

Early boot describes the Linux boot sequence after these steps in firmware.