Although Rust has support for MIPS, it’s currently limited to 32-bit and the o32 ABI, while the more recent MIPS processors are almost entirely 64-bit-capable, and people actually using them are more likely to choose a more performant ABI such as n32. For example, the Chinese homegrown Loongson series of processors support a superset of MIPS64 since Loongson 2, and it would be really nice to leverage the chip’s full potential.
I’m owner of a Loongson 2F netbook and a Loongson 1C development board, and would like to push forward MIPS support in Rust. But I’d first see if anyone else is also interested and perhaps get some advice on the general approach, as overall there seems to be insufficient foundation for elegant ABI support. x32 on AMD64 is missing for example, and the preparatory work really should be done.