Applied it to the compilation / sd card using the url below.
-> https://eewiki.net/display/linuxonarm/BeagleBone+Black#BeagleBoneBlack-BackupBootloader
After removing the micro SD card,
When you insert an SD card into BeagleBone, only one LED blink continuously and
it appears to have no action.
* My main information is as follows.
2. git clone https://github.com/RobertCNelson/ti-linux-kernel-dev.git
3. wget
-c https://rcn-ee.com/rootfs/eewiki/minfs/ubuntu-16.04.1-minimal-armhf-2017-01-14.tar.xz
Thank you.