sorry, i run it on older meta-openembedded,so i dont find this WARNING. now, i know it ,thanks.

this is note in README:
"You should find a copy of v2 of the GNU General Public License
   somewhere on your Linux system; if not, write to the Free Software
   Foundation,"

then,can i copy  "kernel-source\LICENSES\preferred\GPL-2.0" to files to fix "obsolete licenses GPL-2.0"?

thanks for your
suggestions very much!