This project builds 3 binaries:

1. zsbl, the zero stage bootloader.
2. fsbl, the first stage bootloader.
3. board_setup, a binary based on fsbl that configures the hardware in hart 0 and then executes ebreak. The other harts are parked in an infinite loop. It's intended to be used from OpenOCD to quickly prepare a HiFive Unleashed board for code to be downloaded into its DDR memory.