meta-riscv

RISC-V Architecture Layer for OpenEmbedded/Yocto

Description

This is the general hardware-specific BSP overlay for RISC-V based devices. The core BSP portion should work with different OpenEmbedded/Yocto distributions and layer stacks.

K3 Platform Support: This layer has been extended from meta-riscv (commit: 41a010a) to include full support for the K3 platform. It supports multiple K3 boards and provides two image output formats:

• SD Card (WIC): Directly bootable .wic image for SD card flashing
• Titan: Partition images for use with the SpacemiT Titan flashing tool

Yocto Compatibility: This layer is developed against the master branch of openembedded-core and bitbake (post-Scarthgap 5.0, towards Styhead 5.1). It has not been tested against stable release branches.

Available Machines

MACHINE	SoC	Supported Boards
k3	SpacemiT K3	COM260, Pico-ITX...

All board variants are built from a single MACHINE=k3 target. The corresponding device trees are included in the bootfs automatically (see conf/machine/k3.conf for the full DTB list).

Firmware Download

Pre-built images are available on the Releases page.

Build Environment

• Recommended: Ubuntu 22.04/24.04, WSL2, or equivalent Linux environment.
• Required tools: git, bash, python3, and Yocto host dependencies (see Yocto Project host packages).

Builds are performed inside a Docker container based on Ubuntu 24.04 LTS (x86_64).

The following packages are installed on top of the base ubuntu:24.04 image:

sudo apt update
sudo apt install gawk wget git git-lfs diffstat unzip texinfo gcc g++ build-essential \
  chrpath cpio python3 python3-pip python3-pexpect python3-git python3-jinja2 \
  python3-subunit xz-utils zstd liblz4-tool lz4 lzop file locales curl make \
  binutils cpp dosfstools iproute2 iputils-ping mesa-common-dev rpcsvc-proto \
  subversion ssh sudo vim p7zip-full netcat-openbsd
sudo locale-gen en_US.UTF-8

Quick Start (K3 Platform)

1. Initialize Workspace

Use the repo tool to initialize the source code:

mkdir riscv-yocto && cd riscv-yocto
repo init -u https://github.com/yingjie-liu-spacemit/spacemit-yocto.git -b k3 -m tools/manifests/riscv-yocto.xml
repo sync
repo start work --all

2. Set Up Build Environment

Run the following command to configure your environment:

. layers/meta-riscv/tools/envsetup.sh

3. Build Images

Both targets produce .wic (SD card) and .ext4 + Titan partition images simultaneously.

Minimal Linux, suitable for quick boot, serial debugging, and basic network testing:

MACHINE=k3 bitbake core-image-minimal

Graphical environment with Weston (Wayland) compositor, supporting simple graphical applications on K3 (GPU acceleration available):

MACHINE=k3 bitbake core-image-weston

4. Default Credentials

User	Password
root	bianbu

5. Flashing / Usage

After a successful build, the image files are located in build/tmp/deploy/images/k3/.

SD Card

Use the dd command to write the .wic image to your SD card (replace /dev/sdX with your actual device identifier):

sudo dd if=core-image-minimal-k3.rootfs.wic of=/dev/sdX bs=4M conv=fsync status=progress
sudo sync

(Replace the filename accordingly if you built core-image-weston.)

Titan Flashing Tool

Titan is SpacemiT's proprietary flashing tool for writing images via USB. The build also generates partition images compatible with Titan (bootfs.ext4, rootfs.ext4, and firmware binaries).

• Download Titan download and usage guide

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Dependencies

• openembedded-core
• bitbake

Contributing

Submit patches via GitHub pull requests. Use GitHub issues to report problems or provide feedback.

Maintainer(s)

• liuyingjie <yingjie.liu@spacemit.com>