FireSim Debugging

In addition to Verilator and VCS software simulation testing, one can use the FireSim tool to debug faster using an FPGA. This tools comes out of the UC Berkeley Architecture Research group and is still a work in progress. You can find the documentation and website at

Chicken Bits

BOOM supports a chicken-bit to delay all instructions from issue until the pipeline clears. This effectively turns BOOM into a unpipelined in-order core. The chicken bit is controlled by the third bit of the CSR at 0x7c1. Writing this CSR with csrwi 0x7c1, 0x8 will turn off all out-of-orderiness in the core. High-performance can be re-enabled with csrwi 0x7c1, 0x0.