Samsung Exynos 7870 Boards
Preparation
Pack the device tree blob in the QCDT format [1] using dtbTool-exynos [2]
by issuing the following commands:
dtbTool-exynos -o stub-dt.img .output/u-boot.dtb
Finally, use mkbootimg by osm0sis [3] to generate the boot image:
mkbootimg -o u-boot.img \
--kernel .output/u-boot-nodtb.bin \
--dt stub-dt.img
Offsets are not provided to mkbootimg as S-BOOT ignores them.
Flashing
If flashing for the first time, it must be done via Samsung’s Download (Odin) mode. Heimdall [4] can be used for flashing, like so:
heimdall flash --BOOT u-boot.img
However, if U-Boot is already installed, you may also use its fastboot interface for flashing. Boot into the boot menu by holding the volume down key. Enable fastboot mode from there, connect the device to your host, then run:
fastboot flash boot u-boot.img
To flash an OS image in internal storage, fastboot is a reliable option.