Renesas H8/300 CPU Architecture Support To Be Dropped In Linux 5.19

The Renesas (originally Hitachi Semiconductor) H8/300 "h8300" CPU architecture support is set to be removed again once more from the Linux kernel. It was previously retired years ago before being restored only to once again fail to be maintained.

As covered last month when it was discussed again about the idea of dropping the h8300 Linux kernel port, back in 2013 this H8/300 CPU support was originally removed as at that point it was already unmaintained for years and even broken GCC compiler support. But then in 2015 a developer stepped up pledging to maintain the port and get it into better shape. But since the end of 2015, there hasn't been much of h8300-specific work with most of the commits touching it just being in regards to tree-wide clean-ups/fixes/changes.

The h8300 has been called the least maintained CPU architecture for the Linux kernel and even h8300 patches lingering in out-of-tree repositories for years haven't ended up being mainlined. Thus for Linux 5.19 this CPU port is again being removed -- this time hopefully for good.

The h8300 architecture is retired after it has been effectively unmaintained for a number of years. This is the last architecture we supported that has no MMU implementation, but there are still a few architectures (arm, m68k, riscv, sh and xtensa) that support CPUs with and without an MMU.

The asm-generic pull is removing this architecture from the mainline kernel.