This is an accessible Forth implementation written directly in machine code for the RISC-V architecture. It is an adaptation of David Smith's excellent x86-64 SmithForth.

Run with make run. You will need to run Linux either on RISC-V hardware or in a QEMU environment.

This project was developed as part of my Master's thesis, in which I thoroughly annotate SmithForth's machine code before porting it to RISC-V. The abstract of my thesis is given below:

In this thesis we present the implementation of a usable Forth system, built using only RISC-V machine code and the Linux operating system as foundations. We begin by justifying the need for accessible programming language implementations, discussing desirable features in educational compilers. Having selected Forth as our language of choice for an educational language implementation, we review existing Forth systems and we motivate why creating a RISC-V port is a worthwhile task. Next we thoroughly examine SmithForth, a high-quality Forth system for the x86-64 architecture. After understanding its principles, we port it to RISC-V, adapting it to our purposes. Finally, we extend this Forth system in Forth itself: we write a RISC- V assembler, we provide useful arithmetic and logic operators plus conditional and looping constructs. We complete our demonstration with a Forth implementation of FizzBuzz, showing the usability of the system.

Those interested can download the thesis document in PDF format.