New NDS32 Port

New Linux ports come and go. Ideally, Linux will run on any piece of hardware that needs it, but some ports lose all their users and are eventually expunged from the kernel, while new hardware might come along, clamoring for a port in the kernel tree, and Linus Torvalds will say no because no one uses that hardware.

This time a promising port appeared on the Linux Kernel Mailing List for the NDS32 architecture. Greentime Hu posted patches that would successfully boot the hardware and would also pass "most LTP-2017 test suites in [the] NDS32 AE3XX platform." Arnd Bergmann liked Greentime's code and approved it for inclusion in the tree, and when Linus asked for some clarity on what the chip was actually for, Arnd said it was a plain low-end RISC architecture, generally used for systems-on-chip (SoC) products, and sat in the same category as ARM32, ARC, MIPS32, RISC-V, and Xtensa architectures.

Greentime added that billions of products had already shipped with his company's hardware, and their customers would get better Linux support if the code were in the main-line tree. In a situation like this, with support from Arnd, a recognizable set of similar chips, and many existing users, a port is likely to go quickly into the kernel, even if – as in this case – the code still barely runs on the hardware. In many other instances, code must be relatively spotless to make it into the tree, but for a port that is unlikely to have any effect on other parts of the kernel, even broken code is often acceptable at first.

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