FPGA development

This page is only for if you want to make changes to the RTL of the bitstream. In most cases you can just use the standard bitstream published in the releases.

Dependencies

• Vivado
• OpenFPGALoader

FPGA Build

The Sonata bitstream is generated using Vivado.

Bitstream

To build the bitstream, make sure to build the baremetal software to create the correct SRAM image. Then run this command:

fusesoc --cores-root=. run --target=synth --setup --build lowrisc:sonata:system

You can also manually set the initial value of the SRAM, for example:

fusesoc --cores-root=. run --target=synth --setup --build lowrisc:sonata:system --SRAMInitFile=$PWD/sw/cheri/build/tests/uart_check.vmem

Build bitstream using nix

Optionally, the bitstream can be built using a nix command:

nix run .#bitstream-build

Note: Vivado must be in one's path for this command to work.