SPU

This is a Soft Processing Unit application with custom assembly language, implementing it's assembler, disassembler and interpreter.

Building release version

(for full stack debug capabilities add FULL_DEBUG macro)

$ mkdir build
$ cd build
$ cmake .. -DCMAKE_BUILD_TYPE=Release
$ make

Assembly

assembler -a [-ho] [filename] < program.gasm [> program.gbin]

Assembles source code in castom assembly to binary file tha could be interpreted

Disassembly

assembler -d [-ho] [filename] < program.gasm [> program.gbin]

Disassembles binary file to human-readable format (assembly language)

Interpreter

interpreter < program.gbin

Interprets binary file and outputs results to stdout

Opcodes

Opcodes could be easily added and modified in ./include/commands.tpl

Opcode	Description	argc
idle	Do nothing, could take one argument to create lable indent	0/1
push	Push argument to stack	1
pop	Pop from stack and discard the result / save result to argument	0/1
add	Pop two values from stack, add them and push the result	0
add	Add the second argumen to the first one	2
sub	Pop two values from stack, subtracted them and push the result [push(pop_2 - pop_1)]	0
sub	Subtract the second argumen from the first one	2
mul	Pop two values from stack, multiply them and push the result	0
mul	Multiply the first argument by the second one	2
div	Pop two values from stack, divides them and push the result [push(pop_2 / pop_1)]	0
div	Divides the first argument by the second one	2
mov	Copies value from the second argument to the first one	2
out	Pops value from stack and prints it to stdout	0
out	Prints argument to stdout	1
jmp	Jumps to position of the argument (usually a goto lable)	1
call	Makes a function call by starting position (usually a goto lable)	1
ret	Returns to the position after last call (is stored in general stack)	0
exit	Stop the program interpretation with exit code 0	0
cmp	Pop two values from stack, compares them and sets comp register [pop_2 cmp pop_1]	0
cmp	Compares arguments and sets comp register	2
jeq	Jumps to position of the argument (usually a goto lable) if comp register is set to equal (0)	1
jl	Jumps to position of the argument (usually a goto lable) if comp register is set to less (-1)	1
jle	Jumps to position of the argument (usually a goto lable) if comp register is set to less or equal (-1 / 0)	1
jg	Jumps to position of the argument (usually a goto lable) if comp register is set to greater (1)	1
jge	Jumps to position of the argument (usually a goto lable) if comp register is set to greater or equal (0 / 1)	1
dec	Decreases the top stack element or the argument	0/1
inc	Increases the top stack element or the argument	0/1
sqrt	Calculates sqrt of the top stack element or the argument	0/1

Done

1. Bacis assembly logic (assembler/disassembler/interpreter)
2. Optimised bytecode conversion and interpretation
3. Basic cli apps and interface (via getopt)
4. Recursive operand parsing
5. Flexible opcode operands, could implement complex calculations, RAM and register calls
6. Limited substraction in operands calculations (better use brackets after substraction, no unary minus, use 0-n)
7. GoTo functionality, lables and jumps
8. Function calls, no real recursion limit
9. call main opening is added to every binary
10. Lables could be used as vars stored in RAM (check out examples)
11. Example programs (solver of quadric equasions and fibinacci recursive calc)
12. Easy opcode list extension and modification with preprocessor codegen
13. Screaming Capybara ASCII art
14. CMake config with fetching my Unkillable Stack ang GoogleTest lib
15. Doxygen docs

TODO

1. Add unit testing and Github Action CI
2. Add video-RAM and draw some circles
3. Status stack for advanced error handling
4. More durable parser and full subtraction support in operands calculations