[Oberon] OP2 compiler assessment

[skulski at pas.rochester.edu]

Richard:

  thank you for describing the OP2. I have heard many times it was not an
easy piece to digest. OK, down the list of things "to do" we can put the
OP2 compiler cleanup and a book titled "Compiler Construction In Real
World".

> Right, so you want to have a processor on your board and you want to
> have an Oberon-2 compiler for it. So, why not "implement" a processor
> for which an Oberon-2 compiler already exists? I think, MIPS would be
> a good candidate because it has a simple "classic" MIPS instruction
> set, and OP2 creator Regis Crelier himself has written a code
> generator for it.

Is MIPS open-source and royalty free? Wikipedia says "Companies can also
obtain an MIPS architectural licence for designing their own CPU cores
using the MIPS instruction set". See
http://en.wikipedia.org/wiki/MIPS_Technologies

The so-called "freedom to operate" is the key. We should not bring
anything to the table that smells like litigation down the road. I am
hoping that the Oberon System is free from legal snags. I asked the key
players how this work should be licensed (GPL, Creative Commons, BSD,
...). Perhaps this is not an issue in Europe, but it is certainly the key
issue in the USA. Lack of a clear statement from the key players is
certainly a big roadblock. I am not sure if they appreciate, how big.

>From the rest of your e-mail I gather that making OP2 emit RISC5 code is
highly nontrivial. However, RISC5 may be the only way to go in order to
steer away from legal issues.

Wojtek