ODROID boot chain

The ODROID-N2 comes with a SPI flash as well as a connector for an eMMC flash and an SD card slot. The SoC is an Amlogic S922X which can boot from all those storages, depending on GPIO configuration and a fallback flow in the mask ROM. For booting from SPI flash, the ODROID-N2 board has a switch, and comes with Petitboot preinstalled¹.

The SPI flash boot flow is as follows:

flowchart LR
    maskrom["mask ROM"]
    spl["U-Boot SPL"]
    uboot["U-Boot main"]
    petitboot(["petitboot"])
    maskrom-->spl-->uboot-->petitboot-->OS

• U-Boot SPL initializes DRAM and loads U-Boot main ("proper")
• U-Boot main is set up to directly load Linux with Petitboot, which implements LinuxBoot

See also

• ODROID forum discussion on porting Petitboot to ODROID-N2

1. https://wiki.odroid.com/getting_started/petitboot/os_installation_using_otg ↩