History

Torsten Ruger 5ddc96718b slight call logic modification simplification, new model is such that the upon start the method: has a message in r0, works on it and returns to the return address. Everything else is up to the caller		2015-11-07 21:59:39 +02:00
..
builtin	simplify the __init	2015-11-07 21:58:19 +02:00
instructions	slight call logic modification	2015-11-07 21:59:39 +02:00
assembler.rb	test the log_level too	2015-11-05 14:05:12 +02:00
boot.rb	fix super class with name mixup	2015-11-07 19:37:38 +02:00
collector.rb	need to collect labels for return	2015-11-03 11:22:26 +02:00
instruction.rb	function call now saves the return address before calling	2015-11-03 11:20:49 +02:00
machine.rb	framework for parfait runtime testing	2015-11-07 17:37:41 +02:00
minimizer.rb	fold last of the virtual into register	2015-10-22 18:16:29 +03:00
padding.rb	fix padding	2015-11-04 10:34:03 +02:00
parfait_adapter.rb	rename internal get/set functions	2015-11-07 17:40:59 +02:00
positioned.rb	first stab at fixing the assembly	2015-11-03 16:24:12 +02:00
README.md	rename phisol to soml	2015-10-23 14:22:55 +03:00
register_value.rb	minor cleaning	2015-11-07 21:55:04 +02:00

README.md

Register Machine

The RegisterMachine, is an abstract machine with registers. Think of it as an arm machine with normal instruction names. It is not however an abstraction of existing hardware, but only of that subset that we need.

Our primary objective is to compile Soml to this level, so the register machine has:

object access instructions
object load
object oriented call semantics
extended (and extensible) branching
normal integer operators (but no sub word instructions)

All data is in objects.

The register machine is aware of Parfait objects, and specifically uses Message and Frame to express call semantics.

Calls and syscalls

The RegisterMachine only uses 1 fixed register, the currently worked on Message.

There is no stack, rather messages form a linked list, and preparing to call, the data is pre-filled into the next message. Calling then means moving the new message to the current one and jumping to the address of the method. Returning is the somewhat reverse process.

Syscalls are implemented by one Syscall instruction. The Register machine does not specify/limit the meaning or number of syscalls. This is implemented by the level below, eg the arm/interpreter.

Interpreter

There is an interpreter that can interpret compiled register machine programs. This is very handy for debugging (an nothing else).

Even more handy is the graphical interface for the interpreter, which is in it's own repository: salama-debugger.

Arm / Elf

There is also a (very strightforward) transformation to arm instructions. Together with the also quite minimal elf module, arm binaries can be produced.

These binaries have no external dependencies and in fact can not even call c at the moment (only syscalls :-)).