Assembler

CPU emulator for custom ASM language

• assembler - tool to compile text assembly to bytecode
• processor - tool to run compiled bytecode

Installation

• Get source code
  • git clone https://github.com/platonvin/Assembler
• Build
  • cd Assembler
  • make

Usage

assembler dir/filename [--log] - compiles text assembly into bytecode. Compiled file is placed near source file

• [--log] means you either pass --log or nothing

processor dir/filename [--log] - runs bytecode. processor will try to find dir/filename.compiled first, then dir/filename

Examples

in programs/ you can find few examples

• circle - draws circle in terminal valid usage:

  assembler programs/circle
  processor programs/circle.compiled
  <radius> <threshold>

  e.g.:

    assembler programs/circle
    processor programs/circle.compiled
    42 100

• factor - calculates factorial valid usage:

  assembler programs/factor
  processor programs/factor.compiled
  <number_to_calculate_factorial_for>

• quadr - solves quadratic equation valid usage:

  assembler programs/quadr
  processor programs/quadr.compiled
  <a> <b> <c>

  floating point numbers are not supported, scaled integers used instead (1.012 -> 1012)

Language reference

All instructions can also be found in [commands.h](src/defines/commands.h)

Instruction	Opcode	Operands	Description
HLT	0x00	None	Halts program execution and terminates the emulator.
PUSH	0x01	1	Pushes a value onto the stack (from register, immediate value, or VRAM address).
POP	0x02	1	Pops a value from the stack (into register, VRAM, or discarded).
ADD	0x03	None	Adds the top two stack values and pushes the result.
SUB	0x04	None	Subtracts the second stack value from the first and pushes the result.
IMUL	0x05	None	Multiplies the top two stack values (signed) and pushes the result.
MUL	0x06	None	Multiplies the top two stack values (unsigned) and pushes the absolute result.
IDIV	0x07	None	Divides the first stack value by the second (signed) and pushes the result.
DIV	0x08	None	Divides the first stack value by the second (unsigned) and pushes the absolute result.
OUT	0x09	None	Pops and prints the top stack value.
IN	0x0a	None	Reads an input value and pushes it onto the stack.
JB	0x0b	1	Jumps to the specified address if the first stack value is less than the second.
JBE	0x0c	1	Jumps to the specified address if the first stack value is less than or equal to the second.
JA	0x0d	1	Jumps to the specified address if the first stack value is greater than the second.
JAE	0x0e	1	Jumps to the specified address if the first stack value is greater than or equal to the second.
JE	0x0f	1	Jumps to the specified address if the first stack value equals the second.
JNE	0x10	1	Jumps to the specified address if the first stack value is not equal to the second.
JMP	0x11	1	Unconditional jump to the specified address.
NEG	0x12	None	Negates the top stack value and pushes the result.
SQRT	0x13	None	Computes the square root of the top stack value and pushes the result.
DUP	0x14	None	Duplicates the top stack value and pushes both copies.
VPOP	0x15	None	Pops two values and stores the second in VRAM at the index specified by the first.
VFL	0x16	None	Outputs VRAM content to the screen and clears VRAM up to the first zero or MAX_VRAM.