====== Boot Loader======
----

===== Boot Media =====
On ODROID-XU3 is a DIP Switch (sw1) to select the [[en:xu3_bootmode_configuration|booting Device]] and CCI Disable/Enable. 

^ SW1-1(Left of Dip Switch) ^ 1st Boot media ^
|OFF|MicroSD card|
|ON|eMMC|

^ SW1-2(Right of Dip Switch) ^ CCI ^
|OFF|Disable|
|ON|Enable|

**SW1-2 MUST be ON(CCI Enable) in order to boot properly.**

===== Boot Sequence =====
 Upon power on the board will search for the boot media. It will perform the following:
  * 1) iROM (Code inside the SoC) will attempt to read the boot media at the first 512 bytes of it. On those first 512 bytes fwbl1 should exist.
  * 2) fwbl1 will load bl2 (SPL) that is part of the U-boot.
  * 3) bl2 will load U-boot.
  * 4) U-Boot will do whats left, such as handle TrustZone, load kernel image if setted. 

=== fwbl1 ===
 This blob is the first thing that CPU will call, we don't have much information on it since its provided by Samsung.\\ Position on SD: 1

=== bl2 ===
 This is the SPL, part of the U-Boot, upon building U-Boot you'll have the mkspl program what will extract it from the u-boot.bin\\ Position on SD: 31

=== u-boot.bin ===
 This is the U-Boot itself built. For more information about U-Boot please check their website:
http://www.denx.de/wiki/U-Boot\\ Position on SD: 63

=== TrustZone Software ===
 This is the blob done by Samsung/ARM to support Trustzone platform.\\ Position on SD: 719

=== Default Env ===
 The default env provided in U-Boot will attempt the following:

  * 1) Load boot.ini script from the first FAT type partition from the boot media.
  * 2) Load kernel from its on media/ramdisk position (This is the Android Boot)