Endian wars and anti-portability: this again?

Summary

Note: This is another really technical post. Those who do not know the difference between a PowerPC and an ARM can probably skip this one – we’ll be back to general audience posts tomorrow! One of my friends made the mistake this evening of linking me to a thread about endianness on that bastion of free expression, Hacker News. (Feel the shade dripping from my virtual pen.). I had drafted this article for Old Blog, but I never published it because I was never quite satisfied that I had a good ending. Well, today Zach has gotten me on with it. I rewrote the ending. I grow weary, dear reader, of the hostility in the broader open source software community against portability. It is exhausting to hear the same tired arguments against portability, especially when in the end most projects end up realising the errors of their ways. So, here are some of the most common arguments I hear and my rebuttals to them. Against “old” architectures The most disturbing, and frequent, argument that I hear is that whatever port I have suggested (or indeed written) is for an “old” architecture that “is not relevant today”. The only architectures supported by Linux that have no commercial viability left are the DEC Alpha AXP and the Itanium. The Itanium has been removed from the Linux kernel with 6.7, which warranted its own article on Old Blog, so I will remove that one from the discussion. In my opinion, the Alpha is a valuable resource for learning some of the core concepts of a RISC architecture. In fact, the team behind RISC-V said they took a significant amount of inspiration from Alpha, and had it not been for some of the oddities around storing quadwords, they may have tried to resurrect it instead of bringing up their own ISA. I think there are still more valuable lessons to learn from it, which is why I’ve been quite happy to see development progressing on it! This has been primarily driven by the Gentoo community around it. As for MIPS, it is still sold and used in products wit...