FPGA based system on chip.
The documentation is available here: https://danodus.github.io/xgsoc/
- RISC-V (RV32IMFC)
- UART (1000000-N-8-1)
- SDRAM (32MiB shared between CPU and video)
- Set associative cache (4-way with LRU replacement policy)
- QVGA (60 Hz) or VGA (60 Hz) HDMI video output with framebuffer (RGB565)
- 480p (60 Hz), 720p (60 Hz) or 1080p (30 Hz) video modes (experimental)
- Graphite 2D/3D graphics accelerator (textured triangles)
- PS/2 Keyboard
- PS/2 Mouse
- USB host for keyboard and mouse (experimental)
- SD Card with hardware SPI
- OSS CAD Suite (https://github.com/YosysHQ/oss-cad-suite-build) (*)
- xPack RISC-V Embedded GCC (https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases) (*)
- Python3 with the following PIP3 packages installed:
pyserial - picocom
- SDL2 (for simulation only)
(*) Extract and add the bin directory to the path.
Note: Tested with oss-cad-suite-darwin-arm64-20240810 and xpack-riscv-none-elf-gcc-14.2.0-1-darwin-arm64.
git clone --recurse-submodules https://github.com/danodus/xgsoc.git
cd xgsocIf the repository has been cloned without the --recurse-submodules option, do the following:
git submodule update --init
git pull
git submodule update --recursivecd rtl/ulx3s
make clean;make CONF=<conf> VIDEO=<video mode> prog # for example, CONF=bvkm VIDEO=vga (see below)
cd ../../src/hello
make run SERIAL=<serial device>
picocom -b 1000000 <serial device>| Identifier | Description |
|---|---|
| b | Base (UART, SD Card) |
| v | Video |
| g | Graphite |
| k | PS/2 Keyboard |
| m | PS/2 Mouse |
| u | USB Host (*) |
(*) Experimental (USB host requires a CPU clock of 48 MHz instead of the default 25 MHz)
By default, the configuration is bvgkm.
The following video modes are available:
| Video Mode | Description |
|---|---|
| qvga | 320x240 60Hz |
| vga | 640x480 60Hz |
| 480p | 848x480 60Hz (*) |
| 720p | 1280x720 60Hz (*) |
| 1080p | 1920x1080 30Hz (*) |
(*) Experimental
By default, the video mode is vga.
cd src/test_video
make
cd ../../rtl/sim
make run PROGRAM=../../src/test_video/program.hexTo upload and run the program to the FPGA platform:
cd src/<program name>
make run SERIAL=<serial device>
picocom -b 1000000 <serial device>The following programs are available:
| Name | Description | Min. Config. |
|---|---|---|
| test_mem | Test memory | b |
| test_fs | Test filesystem (SD card content erased) | b |
| bench_dhrystone | Benchmark Dhrystone | b |
| bench_coremark | Benchmark Coremark | b |
| write_sd_image | Write bootable SD card image (see section below) | b |
| hello | Hello world example 76E6 | b |
| factorial | Factorial example | b |
| sinus | Sinus example | b |
| forth | Forth language | b |
| lua | Lua language | b |
| test_ps2_kbd | Test PS/2 keyboard | bk |
| test_ps2_mouse | Test PS/2 mouse | bm |
| test_usb | Test USB host | bu |
| test_video | Test video display | bv |
| test_graphite | Test graphite subsystem | bvg |
- Insert the SD card
- Open a serial terminal
- Start the image writer utility:
cd src/write_sd_image
make run SERIAL=<serial device>- Send the data to write:
cd ../<program name>
make write SERIAL=<serial device>
Press a key when completed. The SD card image will automatically be read and executed unless a key is sent via UART during the first seconds of the boot process.
- The SoC is based on the Oberon project for the ULX3S available here: https://github.com/emard/oberon
- The USB host is based on usb_host available here: https://gitlab.com/pnru/usb_host