U-Boot for the Ouya Game Console (ouya)
DISCLAMER! Moving your Ouya to use U-Boot assumes replacement of the
vendor bootloader. Vendor android firmwares will no longer be able to run on the
device. This replacement IS reversible if you have backups.
Quick Start
Build U-Boot
Process U-Boot
Flashing U-Boot into the eMMC
Boot
Self Upgrading
Build U-Boot
$ export CROSS_COMPILE=arm-none-eabi-
$ make ouya_defconfig
$ make
After the build succeeds, you will obtain the final u-boot-dtb-tegra.bin
image, ready for further processing.
Process U-Boot
DISCLAMER! All questions related to the re-crypt work should be asked
in re-crypt repo issues. NOT HERE!
re-crypt is a tool that processes the u-boot-dtb-tegra.bin binary into form
usable by device. This process is required only on the first installation or to
recover the device in case of a failed update. You need to know your device
individual SBK to continue.
$ git clone https://gitlab.com/grate-driver/re-crypt.git
$ cd re-crypt # place your u-boot-dtb-tegra.bin here
$ ./re-crypt.py --dev ouya --sbk <your sbk> --split
where SBK has next form 0xXXXXXXXX 0xXXXXXXXX 0xXXXXXXXX 0xXXXXXXXX
The script will produce bct.img and ebt.img ready to flash.
Flashing U-Boot into the eMMC
DISCLAMER! All questions related to fusee-tools should be asked in the proper
place. NOT HERE! Flashing U-Boot will erase all eMMC, so make a backup before!
Permanent installation can be performed by pre-loading just built U-Boot into RAM. Bct and bootloader will end up in boot0 and boot1 partitions of eMMC.
You have to clone and prepare fusee-tools from here: https://gitlab.com/grate-driver/fusee-tools according to fusee-tools README to continue.
Bootloader preloading is performed to device in APX/RCM mode connected to host
PC. This mode can be entered from testpad on motherboard with device connected
to the host PC. Host PC should detect APX USB device in lsusb.
U-Boot pre-loaded into RAM acts the same as when it was booted “cold”. Currently U-Boot supports bootmenu entry fastboot, which allows to write a processed copy of U-Boot permanently into eMMC. This is how U-Boot can be preloaded using fusee-tools:
$ ./run_bootloader.sh -s T30 -t ./bct/ouya.bct --b u-boot-dtb-tegra.bin
While pre-loading U-Boot, interrupt bootflow by pressing CTRL + C (USB keyboard
must be plugged in before U-Boot is preloaded, else it will not work), input
bootmenu from the keyboard and hit enter. The bootmenu will appear. There, select
fastboot using the up and down arrows and enter key. After, on host PC, do:
$ fastboot flash 0.1 bct.img
$ fastboot flash 0.2 ebt.img
$ fastboot reboot
Device will reboot.
Boot
To boot Linux, U-Boot will look for an extlinux.conf on eMMC. Additionally,
bootmenu provides entries to mount eMMC as mass storage, fastboot, reboot,
reboot RCM, poweroff, enter U-Boot console and update bootloader (check
the next chapter).
Flashing bct.img and ebt.img eliminates vendor restrictions on eMMC and
allows the user to use/partition it in any way the user desires.
Self Upgrading
Place your u-boot-dtb-tegra.bin on the first partition of the USB. Enter
bootmenu, choose update bootloader option with Enter and U-Boot should update
itself. Once the process is completed, U-Boot will ask to press any button to reboot.