Yet another post about how I'm digging into Elbrus machines architecture. This one isn't about the CPU though.

Interestingly, but actually Elbrus SPARC machines (in short, E90S) are absolutely incompatible with Sun machines. Instead, they have a lot in common with E2K machines.

Like in E2K, SPARC cores communicate interruptions with Intel's APIC. The northbridge between E90S and E2K is absolutely the same. The SIC controller has small differences. The BIOS firmware shares a lot of code between sparc and e2k.

Also there is no real reason to do so (?) but their proprietary compiler has codegen for SPARC as well. Though I remember they also recommended using normal GCC.

Unmodified Linux will not be able to boot on E90S, let alone unmodified Solaris. Damn I thought their SPARC machines are quite boring.