rubyx/lib/risc
Torsten Ruger 3cc9175efa start BranchListener
but on hold, since it needs positions before we have them
Must create them during collection phase
2018-06-14 21:29:34 +03:00
..
builtin fix function call and simple call logic 2018-05-19 12:21:20 +03:00
instructions start BranchListener 2018-06-14 21:29:34 +03:00
position start BranchListener 2018-06-14 21:29:34 +03:00
binary_writer.rb jump was written off the end of binary code, fixed 2018-05-28 11:45:04 +03:00
boot.rb minor simplification 2018-06-09 08:13:37 +03:00
builder.rb another million index fixes 2018-05-14 15:17:04 +03:00
collector.rb get the label int to work consistently 2018-05-30 10:54:18 +03:00
fake_memory.rb use fake memory 2018-05-28 15:09:59 +03:00
instruction.rb give interpreter a clock and pc 2018-05-23 18:05:22 +03:00
interpreter_platform.rb dragging the extra through resets 2018-05-25 19:04:48 +03:00
interpreter.rb fixes outstanding misc, All green 2018-06-10 13:19:55 +03:00
machine.rb introduce the LabeListener to move instructions along when first code position changes 2018-06-09 22:13:43 +03:00
method_compiler.rb loading label must translate the labels too 2018-05-24 19:20:06 +03:00
padding.rb fix opal error 2018-05-20 15:51:36 +03:00
parfait_adapter.rb fixing the binary code indexes 2018-05-28 18:20:09 +03:00
platform.rb make the interpreter platform 2018-05-17 09:31:36 +03:00
README.md polish docs 2018-03-11 16:11:15 +05:30
risc_value.rb random checkin 2018-05-14 12:38:44 +03:00
text_writer.rb write adjusted address 2018-05-31 00:07:58 +03:00

Risc Machine

The RiscMachine, 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 typed code 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 RiscMachine only uses 1 fixed register, the currently worked on Message. (and assumes a program counter and flags, neither of which are directly manipulated)

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 Risc 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 (and nothing else).

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

Arm / Elf

There is also a (very straightforward) 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 :-)).