This repository contains files and projects that will be useful during the Fomu workshop.
Fomu aims to be accessible from multiple levels, from interactive REPL-style scripting all the way down to low-level hardware description languages.
Micropython is a work-in-progress port to Fomu. Currently the following features exist:
- Manipulate RGB LED
- Read SPI flash ID
- dfu-util
- terminal emulator (screen, Tera Term, picocom, etc.)
To load Micropython, use dfu-util:
# If this is the first time loading Micropython
$ dfu-util -D micropython-fomu.dfu
# If Micropython has already been loaded
$ dfu-util -eThen access the USB serial port using your serial program of choice.
You can directly program the RISC-V softcore on Fomu. The VexRiscv implements an RV32I core with no multiply unit.
- Risc-V Toolchain
- make
The riscv-blink/ directory contains a simple "blink" program. This utilizes the LEDD hardware PWM block to produce a pleasing "fade" pattern. The riscv-blink/ example project is entirely self-contained. All you have to do is go into the directory and run make.
For a more advanced example, the riscv-usb-cdcacm/ directory contains a program that enumerates as a USB serial port. This simply echoes back any characters that are typed, adding 1 to the value. For example, if you send "a", it will respond with "b".
As with micropython, you can load these binaries with dfu-util -D output.bin.
HDL interfaces directly with the hardware. With Verilog, you have complete control over the chip. For easier debugging, LiteX lets you write in Python, which provides you with a USB debug bridge.
The first is a simple Verilog blink, and is located in the verilog-blink/ directory. Go into this directory and run make FOMU_REV=???. You will need to specify the version of Fomu you're using. Once it is built, you can load the bitstream with dfu-util -D blink.bin.