Building an Octa-core 32-bit RISC-V PC on an FPGA board

We built an octa-core 32-bit RISC-V PC running the X Window System (X11) on the Wukong board, an FPGA board from Qmtech.
The USB-connected keyboard and mouse use the Wireless Combo MK245 NANO from Logitech, known in Japan as Logicool.
This PC is based on https://github.com/litex-hub/linux-on-litex-vexriscv etc.

Linux on LiteX-VexRiscv

The Linux on LiteX-VexRiscv uses 32-bit RISC-V VexRiscv as a soft microprocessor.
An SoC around the VexRiscv is created using LiteX as the SoC builder and LiteX’s cores.

RISC-V PC

We built a RISC-V PC with the following configuration.

• RISC-V single board computer
  • Qmtech Wukong board
  • Alternative to Pmod usb_host_x4
• USB wireless keyboard mouse combo
• HDMI display
• MicroSD
• USB cable (USB-UART)

The main specifications of the RISC-V PC based on the Wukong board are as follows.

• CPU: Octa-core 32-bit RISC-V
  • ISA: RV32IMAFDC + AES custom extension
  • Operating frequency: 100 MHz
• DRAM: 256 MB
• Ethernet: 100/1000 Mbps
• USB: 2 ports (max 4 ports)
• Display resolution: 1024×600
• Storage
  • MicroSD: for OpenSBI, Linux & rootfs

Summary

We built an octa-core 32-bit RISC-V PC running the X Window System (X11) on the Qmtech Wukong board using modified LiteX/VexRiscv and others.
The feature of this PC is that the modified LiteX/VexRiscv realizes the USB host function.
We think it is a good point that many applications can be diverted by making the ISA of this CPU the same as that of the SaxonSoc.