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.