Required Hardware

For this workshop, you will need a Fomu board.

Aside from that, you need a computer with a USB port that can run the Required Software.

You should not need any special drivers, though on Linux you may need sudo access, or special udev rules to grant permission to use the USB device from a non-privileged account.

This workshop may be competed with any model of Fomu, though there are some parts that require you to identify which model you have. See the Which Fomu do I have? section.

Which Fomu do I have?






Bash Command

export FOMU_REV=hacker

export FOMU_REV=pvt


Hacker Hardware Front without case

Production Hardware Front without case


Hacker Hardware Back without case

Production Hardware Back without case

In Case

Hacker Hardware Back with case

Production Hardware Back with case


Hacker Hardware Annotated Diagram

Production Hardware Annotated Diagram


dark blue

cyan / light blue


Fomu Hacker running DFU Bootloader vX.X.X

Fomu PVT running DFU Bootloader vX.X.X


These are the original design and cut corners to make it easier to manufacture. If you received one directly from Tim before 36C3, you probably have one of these. Hacker boards have white silkscreen on the back.

If you ordered a Fomu from Crowd Supply, this is the model you’ll receive. It is small, and fits in a USB port. There is no silkscreen on it. This model of Fomu has a large silver crystal oscillator that is the tallest component on the board.




Received at

From Tim at 35C3, CCCamp19, HackADay Supercon 2019

At RISC-V Summit 2019, 36C3, Crowdsupply, Mouser

Buy more

End of Life



There are also Fomu EVT boards which were shipped to early backers of the Fomu crowd funding campaign. This model of Fomu is about the size of a credit card. It should have the text “Fomu EVT3” written across it in white silkscreen. If you have a different EVT board such as EVT2 or EVT1, they should work also.