Android Customizing U-Boot

Toolchain setup for manual U-Boot build

$ export ARCH=arm
Setup the toolchain path to point to arm-eabi- tools in prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin
$ export CROSS_COMPILE=//prebuilts/gcc/linux-x86/arm/arm-eabi-4.8/bin/arm-eabi-

Manual build Bootloader 

Change directory to U-Boot

$ cd //bootable/bootloader/uboot-imx

Execute following commands:

clean tree:
$ make mrproper

Choose build for SD card or NAND flash:
$ make mx6var_som_sd_android_defconfig
or
$ make mx6var_som_nand_android_defconfig

Build U-Boot:
$ make -j4

This command will generate the U-Boot images 'SPL' and 'U-Boot'.

Flash newly created bootloader

To flash the newly created SPL and U-Boot images, replace the following files in the recovery SD card image.

SPL Images:

SPL-nand ---------------- NAND SPL
SPL-sd ------------------ eMMC / SD SPL

U-Boot Images:

u-boot-var-imx6-nand.img - NAND U-Boot
u-boot-var-imx6-sd.img --- eMMC / SD U-Boot

Path Where to Replace Android Image: /opt/images/Android/

Sync and safely remove the SD card after replacing image.

Boot And Flash new updated bootloader

Flash the Android images

• Note: Be careful this will wipe out your Android partitions and re-create it on eMMC / NAND.