Renesas H8/300 CPU Support Looks To Be Dropped Again From The Linux Kernel

The Linux kernel support is looking to drop support for Renesas (Hitachi) H8/300 CPUs once again.

The "h8300" Linux port for the obsolete Renesas H8/300 series processors/microcontrollers is once again looking to be removed. Back in 2013 the Linux kernel originally dropped support for the old H8/300s as no one objected while a number of kernel developers "acknowledged" its removal. Way back in 2013 it was considered "dead for several years, the kernel for it has not compiled for ages, and recent versions of GCC for it are broken."

But then in 2015 a developer stepped up wanting to maintain the H8300 port for the Linux kernel... He rewrote some of the architecture code so at least would build and in better shape than previously. That restored H8300 support was merged into Linux 4.2 and then... Sat there.

Since the end of 2015 there hasn't been much H8300-specific work with most of the commits since then being for basic header cleanups/fixes and other mostly trivial changes as part of cross-architecture changes. Now due to the lack of activity to the kernel code and Renesas H8 MCUs being even more obsolete, it's being eyed for removal once more.

Linux looks set to remove H8 arch support (again).

Longtime kernel developer Christoph Hellwig sent out a request for comments on removing the arch/h8300 code. He notes the H8300 port hasn't been maintained for quite a while with "even years old pull request lingering in the old repo." Plus with the fact of the code being "rather fringe to start", he's hoping to see the port removed. Clearing out the H8300 CPU code from the linux kernel would reduce the ongoing maintenance burden by some 7k lines of code.

Kernel developer Arnd Bergmann also commented that H8300 is Linux's "least actively maintained architecture we have at the moment, and probably the least useful."

Thus this PR now stands for seeing the removal of the Renesas H8/300 architecture support for the Linux kernel for hopefully a final time given how obsolete the hardware is and unlikely anyone still finding such hardware would be running a modern kernel.