EtherVM

A lightweight, efficient virtual machine implementation in Rust, designed for educational purposes and as a foundation for more complex emulation projects.

Features

1. CPU Emulation

• Basic CPU structure with registers and program counter
• Instruction fetch-decode-execute cycle
• Initial instruction set with basic arithmetic operations (ADD, SUB, MUL, DIV)
• Error handling for unknown opcodes and division by zero
• Unit tests for arithmetic operations

2. Memory Management Unit

• Implementation of a Memory Management Unit (MMU)
• 64KB of emulated memory
• Byte and word (32-bit) read/write operations
• Integration of MMU with CPU for instruction fetching and data operations
• LOAD and STORE instructions for memory access
• Extended unit tests for memory operations

3. I/O Operations

• IOController and IODevice trait for managing input/output operations
• ConsoleDevice implementation for basic console I/O
• INPUT and OUTPUT instructions added to the CPU
• MockIOController for testing I/O operations without actual console interaction
• Flexible architecture allowing easy addition of new I/O devices

4. Expanded Instruction Set

• Logical operations: AND, OR, XOR, NOT
• Shift operations: SHL (shift left), SHR (shift right)
• Comparison operation (CMP) with flags register
• Control flow instructions:
  • JMP (unconditional jump)
  • JE (jump if equal)
  • JNE (jump if not equal)
  • JG (jump if greater)
  • JL (jump if less)
• Modified instruction decoding to accommodate the expanded set
• Comprehensive unit tests for new instructions and operations

Project Structure

• src/
• ├── main.rs # Entry point of the application
• ├── cpu.rs # CPU implementation with instruction set
• ├── memory.rs # Memory Management Unit implementation
• └── io.rs # I/O Controller and devices

Usage

• To build and run the virtual machine:

  • cargo build
  • cargo run

• To run the tests:

  • cargo test

Future Improvements

• Implement a simple assembler for easier program input
• Add more complex I/O devices (e.g., virtual disk, network interface)
• Implement interrupt handling and system calls
• Create a debugger interface for step-by-step execution and memory inspection

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.