The Berkeley Out-of-Order Machine (BOOM) is an open source RV64G RISC-V core written in the Chisel hardware construction language, and mainly ASIC optimized. However, it is also usable on FPGAs, and developers support the FireSim flow to run BOOM at over 90 MHz on Xilinx Ultrascale+ FPGAs found in Amazon EC2 F1 instances.
The BOOM core was created at the University of California, Berkeley in the Berkeley Architecture Research group, in order to create a high performance, synthesizable, and parameterizable core for architecture research.
To read more, please visit: https://www.cnx-software.com/2018/12/13/boom-risc-v-core-amazon-ec2-f1/.