

Unfortunately it seems to be a completely proprietary kernel. I did find a paper on it (presented by Huawei in a conference): https://www.usenix.org/conference/osdi24/presentation/chen-haibo
The first line of the abstract reads
This paper presents the design and implementation of HongMeng kernel (HM), a commercialized general-purpose microkernel that preserves most of the virtues of microkernels while addressing the above challenges.
Another interesting tidbit from the paper:
We started the HongMeng kernel (HM) project over 7 years ago to re-examine and retrofit the microkernel into a general OS kernel for emerging scenarios. To be practical for production deployment, HM achieves full Linux API/ABI compatibility and is capable of reusing the Linux applications and driver ecosystems such that it can run complex frameworks like AOSP [42] and OpenHarmony [35] with rich peripherals.
I wonder if immutable systems could negate the need for kernel anti cheat. If the game can ensure the current kernel and image is one from a list of acceptable ones, it doesn’t need to kernel anti cheat. They could do this by comparing the checksum or something.