(1) The directories below are licensed under Apache License, Version 2.0.
./rk3588/hardware/

(2) The directories below are licensed under GNU General Public License, version 2.
./common/kernel/
./common/sdk_linux
./common/vendor
./rk3588/kernel/
./rk3566/sdk_linux
./rk3566/vendor

(3) The directories below are licensed under MIT
./common/kernel/
./rk3588/kernel/

(4) The directories below are licensed under BSD-3-Clause
./common/kernel/
./rk3588/kernel/

(5) The directories below are licensed under GPL-2.0 OR MIT
./rk3588/kernel/

(6) The directories below are licensed under GPL-2.0+ OR MIT
./rk3588/kernel/

(7) The directories below are licensed under GPL-2.0 WITH Linux-syscall-note
./common/kernel/
./rk3588/kernel/

(8) The directories below are licensed under GPL-2.0 WITH Linux-syscall-note OR MIT
./common/kernel/
./rk3588/kernel/

As for the specific use of the licenses,  please refer to the relevant description in the documents.