A Complete Open Source Network Stack For BlackParrot

Abstract

Dennard scaling has come to an end. General-purpose architecture now can hardly have major improvements in power efficiency. Therefore, recently researchers have been actively coming up with hardware designs that do only a limited number of tasks but with great efficiency. Those designs are called hardware accelerators. The future hardware will equip more and more such accelerators and the general-purpose cores will become the hosts of those accelerators. BlackParrot is a Linux-Capable RISC-V Multicore that strives to be the hardware accelerator host widely used by the world. Although BlackParrot has competitive performance and good power efficiency as compared to other RISC-V Cores, the lack of open source I/O devices significantly limits its applications, for example, supporting standard Linux distributions. In my thesis work, a complete network solution has been brought to BlackParrot. This includes creating an Ethernet controller, which contains a ported open source Ethernet MAC, testing a RISC-V PLIC module, porting two embedded libraries that together allow making secure SSL connections, enabling the use of the off-the-shelf network stack from Linux kernel 5.15, and also supporting a Linux distribution from Yocto by doing NFS mounting. Both the software and the hardware are completely open source and have been validated on FPGA.