How to use U-Boot on MX6Q/DL Udoo boards ---------------------------------------- - Build U-Boot for MX6Q/DL Udoo boards: $ make mrproper $ make udoo_defconfig $ make This will generate the SPL image called SPL and the u-boot.img. - Flash the SPL image into the SD card: sudo dd if=SPL of=/dev/mmcblk0 bs=1k seek=1; sync - Flash the u-boot.img image into the SD card: sudo dd if=u-boot.img of=/dev/mmcblk0 bs=1k seek=69; sync - Insert the SD card in the board, power it up and U-Boot messages should come up.