UBL need to be modified to fit your board, this doc focus on how to compile ubl. 1. source toolchain is a must $ source set_env.sh 2. build all targets once $ make -C ti-flash-utils/DM36x/GNU/ubl/ clean $ make -C ti-flash-utils/DM36x/GNU/ubl/ 3. build specified target for saving time $ make -C ti-flash-utils/DM36x/GNU/ubl/build/ TYPE=sdmmc clean $ make -C ti-flash-utils/DM36x/GNU/ubl/build/ TYPE=nand clean $ make -C ti-flash-utils/DM36x/GNU/ubl/build/ TYPE=nor clean $ make -C ti-flash-utils/DM36x/GNU/ubl/build/ TYPE=sdmmc SDRAM_BASE=0x80000000 SDRAM_SIZE=0x08000000 PLL_SETTING=ARM297_DDR270_OSC24 $ make -C ti-flash-utils/DM36x/GNU/ubl/build/ TYPE=nand SDRAM_BASE=0x80000000 SDRAM_SIZE=0x08000000 PLL_SETTING=ARM297_DDR270_OSC24 $ make -C ti-flash-utils/DM36x/GNU/ubl/build/ TYPE=nor SDRAM_BASE=0x80000000 SDRAM_SIZE=0x08000000 PLL_SETTING=ARM297_DDR270_OSC24 available PLL_SETTINGs are here, you can add more settings based on your code in ti-flash-utils/DM36x/Common/src/device.c ARM297_DDR270_OSC24 ARM270_DDR216_OSC24 ARM297_DDR277_OSC27 ARM216_DDR173_OSC19P2 ARM216_DDR173_OSC24 ARM432_DDR340_OSC24 ARM297_DDR243_OSC24 ARM445_DDR351_OSC24 ======================================================================================================= history 2017-12-21 dsc: goto ti-flash-utils/DM36x/GNU/ubl/ and make, then generates all images for all available PLL settings mod: ti-flash-utils/DM36x/GNU/ubl/build/makefile mod: ti-flash-utils/DM36x/GNU/ubl/makefile add: ti-flash-utils/DM36x/GNU/ubl/device.mak ----------------------------------------------------- 2017-12-08 dsc: avoid udivsi3 err after clean mod: ti-flash-utils/DM36x/GNU/ubl/build/makefile