[0d0a]

I'm also writing a processor module, and reading this is a bit encouraging to eventually write about it once it's finished.

Getting off the ground wasn't the hardest part so far. You can just pick the skeleton module that already comes with Ghidra, then lookup some existing simpler modules like the one for z80 to figure out how instructions are put together. You also have the script `DebugSleighInstructionParse` to check how bits are being decoded, very useful when you screw up some instruction definitions.

Unfortunately, you bump into a lot of jargon heavy error messages. The first time you hear about "Interior ellipsis in pattern", you sure have no idea what's that about. Now repeat that experience for several messages.

Then the hardest challenge is how to even test the module outside of some quick disassemblies. There's `pcodetest` but the setup is cumbersome and it seems more about validating instruction decoding rather than semantics. I might just write my own validation using pcode emulation and compare the register state against another emulator's instruction trace...

[mumbel]

Pcodetest is more about validating the implementation of the instruction, sure it has to decode, but the benefit is most a base level set of logic that can be emulated. And definitely not a fan of the setup to get it going (also only helpful if you have a semi recent C compiler)

[0d0a]

Oh nice, it wasn't clear from the test suite if that was the case, I'll give it a closer look.

Judging from the python scripts, it seems to expect a whole binutils toolchain (so not just compiler but also objdump, readelf...) and that would be a blocker for me.