So far, we can't even get Samsung to have their FOSS kernel stuff published in a buildable and usable form - its basically impossible to build their recent kernels with their recent toolchains without finding out that some obscure config option was skipped or that some file didn't survived the pre-release purge or that it requires some obscure Linux distribution to run on. And if you get it to build, chances that it will boot are slim. (Good luck finding out if there's a working UART somewhere on chip pins and it's not hidden behind hypervisor and fuses)