Linus Torvalds has come out strong against proposed support for RISC-V big endian capabilities within the Linux kernel.
In response to a mailing list comment whether RISC-V big endian "BE" patches being worked on would be able to make it for this current Linux kernel cycle. Linus Torvalds initially wrote:
"Oh Christ. Is somebody seriously working on BE support in 2025?
WHY?
Seriously, that sounds like just stupid. Is there some actual real reason for this, or is it more of the "RISC-V is used in academic design classes and so people just want to do endianness for academic reasons"?
Because I'd be more than happy to just draw a line in the sand and say "New endianness problems are somebody ELSES problem", and tell people to stop being silly.
Let's not complicate things for no good reason. And there is NO reason to add new endianness.
RISC-V is enough of a mess with the millions of silly configuration issues already. Don't make it even worse.
Tell people to just talk to their therapists instead. That's much more productive."
There aren't currently any RISC-V hardware implementations that support big endian (although I guess someone must have tried it on a simulator), so supporting it in the Linux kernel is about as useful as supporting any other hypothetical CPU that only exists on paper. The mainline kernel is meant for computers that exist in the real world, so supporting BE RISC-V should only happen after such CPUs have actually been made. As things stand, there's nothing to suggest that anyone will bother making them, so the Linux maintainers shouldn't bother supporting them.
I really appreciate the accessible explanation, thank you!