Hundreds of thousands of linux-based smartnic cards, actually. Fun stuff. Those particular ones were EOLd and have been replaced with ARM but the MIPS based ones will live on in the datacenters until they die, I'm sure.
> Like previous you, I have to admit I'm skeptical but would be happy to be wrong
Seriously, you are going to be delighted to be wrong. On your linux machine, go write a go program and write "GOOS=darwin GOARCH=arm64 go build ..." and you will have yourself an ARM mac binary. Or for going the other way, use GOOS=linux GOARCH=amd64. It really is that simple.
I install QEMU (I have the same setup locally), then it's one line each to run unit tests for: Linux 386, arm64, riscv64, ppc64le and s390x.
With QEMU installed, all you have to do is:
GOARCH=bla go test ./...The Go build system runs under your current architecture, cross-compiling tests to your target architecture.
Then, the Go test runner also runs under your current architecture, orchestrating running your cross compiled test binaries.
Since you registered to run cross-compiled binaries under QEMU, those test binaries magically run through QEMU.
The Go test runner collects test results, and reports back to you.
The first run might be slowish, as the Go compiler needs to cross compile the standard library and all your dependencies to your target platform. But once that's done and cached, and if your tests are fast, the edit-test cycle becomes pretty quick.
"EdgeOS" is based on Linux, and people run vanilla Linux distributions on those boxes, as well as OpenBSD and NetBSD.
I wonder how long Marvell will continue selling those Octeon MIPS64 chips, though. Marvell (then Cavium) switched to ARM nearly a decade ago (2016) for newer chips in the Octeon series. I think Loongson sells more modern MIPS64 (or at least MIPS64-like) chips, but they don't seem to be commercially available outside China.
Like previous you, I have to admit I'm skeptical but would be happy to be wrong.