X-Kernel

中文版

X-Kernel is a multi-architecture monolithic kernel written in Rust. It provides a modular subsystem design covering memory management, process scheduling, file systems, networking, device drivers, and TEE (Trusted Execution Environment) support. The kernel targets multiple hardware architectures (AArch64, x86_64, RISC-V 64, LoongArch64) and runs on both virtual and physical platforms.

This project is inspired by StarryOS, an experimental monolithic OS based on ArceOS, developed by Tsinghua University.

Supported Architectures

• RISC-V 64
• LoongArch64
• AArch64
• x86_64

Supported Platforms

• QEMU
• Hygon CSV Environment
• Linux kylin-x Pkvm Virtual Machine

Features

• Tee support

Quick Start

1. Install dependencies

# Rust toolchain
rustup target add aarch64-unknown-none-softfloat

# QEMU (Debian/Ubuntu)
sudo apt install qemu-system

Musl toolchain

Architecture	GCC Version	Musl Version	Origin Link
x86_64	11.2.1	git-b76f37f (2021-09-23)	musl.cc
aarch64	11.2.1	git-b76f37f (2021-09-23)	musl.cc
riscv64	11.2.1	git-b76f37f (2021-09-23)	musl.cc
loongarch64	13.2.0	1.2.5	LoongsonLab

2. Config kernel

start from a platform defconfig

cp platforms/aarch64-qemu-virt/defconfig .config
make defconfig

make defconfig expands the copied minimal defconfig into a full .config.

change configuration

If you want to change the kernel configuration, use the following command to open the menuconfig interface:

make menuconfig

This updates the .config file in the project root, which is then used for builds.

refresh an existing configuration after Kconfig changes

make oldconfig

This is the Linux-style interactive refresh flow: it reloads the current .config and asks you to confirm values for newly introduced symbols.

make olddefconfig

This is the non-interactive Linux-style refresh flow: it reloads the current .config and automatically fills newly introduced symbols with their Kconfig defaults.

save the current configuration back to a minimal defconfig

make savedefconfig

This writes a minimized ./defconfig containing only values that differ from Kconfig defaults. It is useful when updating a platform defconfig after menuconfig changes.

3. Prepare rootfs

Download a pre-built root filesystem image:

make rootfs                        # alpine-busybox (musl, default)
make rootfs ROOTFS_VARIANT=debian-busybox # debian-busybox (glibc)
make rootfs ROOTFS_VARIANT=debian-systemd # debian-systemd (glibc)

Or you can build your own root filesystem image(only supported ext4 and musl for now)

4. Build

You can build the kernel

make build

this will create a kernel image from .config

For x86_64, make build also creates boot media artifacts in the project root:

• xkernel_<platform>.bzimg: LinuxBoot/direct boot image
• xkernel_<platform>.uefi.img: UEFI FAT boot disk containing BOOTX64.EFI, axboot.toml, and the kernel ELF

5. Build and run on QEMU

we support directly running the kernel on QEMU

cp platforms/aarch64-qemu-virt/defconfig .config
make run

cp platforms/x86_64-qemu-virt/defconfig .config
# Default x86_64 QEMU flow: LinuxBoot/direct boot
make run

# Optional x86_64 UEFI flow: OVMF + generated UEFI boot disk
make run UEFI=y

# x86-csv UEFI + SEV launch helper
bash scripts/start.sh

For the x86_64 UEFI flow, the host needs OVMF firmware files (for example /usr/share/OVMF/OVMF_CODE_4M.fd and OVMF_VARS_4M.fd).

License

This project is now released under the Apache License 2.0. See the LICENSE and NOTICE files for details.