A simple stack based virtual machine capable of executing specially designed bytecode files + assembly language designed to be used as a compilation target for student compiler lessons.
This repository produces 2 individual packages.
The core package consisting of all the source code for the virtual machine and all related functionality. You can use package management to include this into your own projects such as for use as a compilation target in your own compiler.
Available as:
- Nuget package here
A console application that can be installed as a dotnet tool and invoked using the qkvm command. It is capable of running code, assembling bytecode, inspecting bytecode and providing quick access to documentation. You should install this to run code produced in a stand-alone manor and not as a part of another application.
The virtual machine is a stack based virtual machine. Each instructions is fetched from a bytecode file, decoded, mapped to an existing instruction, and then executed. All common virtual machine instructions are supported for 32 bit integers, 32 bit unsigned integers, and 32bit floating point numbers.
The virtual machine has limited interaction with the host machine. Currently no access to the host's file-system is supported though the functionality could be added in future revisions.
For more information on the bytecode file format read about the module structure.
All the supported hardware instructions can be found here.
Bytecode files (modules) can provide exports and imports which can allow code to be generated in smaller pieces and then statically linked together to create a single larger executable. This can be done using the Linker class or via the command line tool with the qkvm link command.
Once 2 modules have been linked, a new third module will be produced which is the combination of the original 2. To link more than 2 modules together you can chain calls to the link function. This is done automatically if using the command line tool.
An assembly language is also provided to allow one to write code in a human readable format before assembling it into executable bytecode.
For more information on the syntax of the assembly language you can read about it here.
A simple Visual Studio Code extension has been developed that supports syntax highlighting, code inspection, and code suggestions for this specific assembly syntax. You can download it on the releases page as a .zip file. To install it simply unzip it into your <user home>/.vscode/extensions directory.
Assembling of assembly files to bytecode files is able to be done using the Assembler class or via the command line tool with the qkvm assemble command.
You can experiment with the assembler online by visiting this repository's related github-pages site.