about the kernel for Letux 400 (MIPS)
Letux 400 is a Ingenic JZ4730 (MIPS SoC) based mini-notebook with 7 inch 480x800 screen.
There are very old 2.4 kernels with good hardware support by the original designers from China (Skytone).
There is also a newer 2.6 kernel which recently got an update that is included here in the Letux-kernel project. Check the sources for git tags like "letux-400-2.6.*".
Finally, there is very small progress on modernizing everything so that a 4.* kernel becomes available. The main hurdle is that modern kernels heavily use "Device Tree" which was only available for PowerPC in 2.6 kernel and neither ARM nor MIPS.
And, although modern kernels support the JZ4740 and JZ4780 SoC the differences to the JZ4730 are not minimal and there is almost no documentation (we have no User Manual of the JZ4730) except the 2.4 and 2.6 kernel sources.
So this is a major task to re-implement the 2.6 patches for the latest kernel and progress is very slow.