TIL MediaTek in 2022 DMCA'd a bunch of repositories with "proprietary" code but it's just sources for LK bootloader, binaries, etc.
https://github.com/github/dmca/blob/master/2022/11/2022-11-10-mediatek.md
Discussion
Little Kernel is licensed under MIT.
https://github.com/littlekernel/lk/blob/master/LICENSE
That's why you better choose GPL for hardware projects.