EdgeOS

EdgeOS is an independent Unix-like kernel for x86_64 and AArch64. It is not a Linux fork. Linux userspace is the compatibility target: the kernel loads Linux ELF64 binaries and implements the Linux-facing system call and device interfaces needed by existing software.

Development systems currently boot Debian with systemd on both architectures. X11/XFCE, KDE Plasma on Wayland, Chromium, Firefox, LibreOffice and Docker have all been run on EdgeOS development VMs using unmodified Debian packages.

This repository contains the kernel. Root filesystems, desktop packages and virtual-machine management tools are separate projects.

Current tree

	Count
Canonical Linux syscall IDs	385
Shared syscall handlers	299
AArch64 policies using shared handlers	265
BSD driver manifests	258
Buildable BSD driver packages	253
Source-locked BSD files	2,862

The syscall figures come from tools/syscalls/linux_syscall_inventory.json. The driver figures come from the generated BSD Bridge build plan and source locks. These inventories are checked during the build.

Kernel

Architecture directories contain entry code, context switching, interrupt plumbing, page-table operations and platform bring-up. Process semantics, VFS, networking, scheduling, IPC and Linux-visible behavior are shared. A feature implemented in common code is built into both architecture targets.

Area	Present in the tree
Boot	x86 Multiboot/Multiboot2, AArch64 UEFI, Linux-style kernel command line, block-root selection and cpio or gzip-compressed initramfs
Linux ABI	Linux ELF64, architecture syscall tables, vDSO, Linux ioctls, socket interfaces and the procfs/sysfs/devtmpfs device model
Processes	fork, vfork, clone, clone3, exec, signals, sessions, process groups, ptrace, pidfds, process waiting and resource accounting
Credentials and limits	UIDs, GIDs, supplementary groups, Linux capabilities, securebits, prctl, resource limits and file permissions
Namespaces and cgroups	Mount, PID, user, UTS, IPC, network, time and cgroup namespaces; cgroup v2 CPU, cpuset, memory, swap, PIDs, I/O and freezer controls
Scheduling	SMP scheduling, affinity, nice levels, SCHED_OTHER, BATCH, IDLE, FIFO, RR and DEADLINE, CPU cgroup controls and utilization clamps
Memory	VMAs, anonymous and file mappings, COW, mmap, mprotect, mremap, madvise, page cache, reclaim, OOM handling, pressure reporting and swap
Synchronization	wait queues, futexes, robust futex lists, futex requeue and waitv, membarrier, mutexes, spinlocks, deferred work and BSD bridge epoch primitives
IPC and events	pipes, PTYs, SysV shared memory, Unix sockets, epoll, eventfd, signalfd, inotify and descriptor passing with SCM_RIGHTS
Time	POSIX clocks and timers, interval timers, timerfd, nanosleep, RTC, HPET and architecture timer backends
VFS	path and inode caches, mount namespaces, modern mount API, descriptors, xattrs, file locks, sparse files, readahead and writeback
Filesystems	tmpfs, initramfs, ext2, ext4, FAT32, FUSE, OverlayFS, cgroup2 and NFSv3 server; read-only SquashFS, EROFS, XFS, Btrfs, exFAT, NTFS, ISO9660 and UDF paths
Storage	block cache, partition discovery, RAM disks, loop devices, device mapper, VirtIO Block/SCSI, NVMe, AHCI, ATA and VMware PVSCSI
Network protocols	IPv4, IPv6, ARP, NDP, ICMP, TCP, UDP, IGMP/MLD multicast, Unix sockets and packet sockets
Network control	rtnetlink, generic netlink, sock_diag, ethtool, IPv4/IPv6 routing, policy and multipath routes, qdiscs, nftables hooks, NAT and connection tracking
Virtual networking	TUN/TAP, veth, bridge with FDB/MDB and VLAN filtering, VLAN, macvlan, ipvlan, bonding, dummy and VRF devices
Native network devices	Intel e1000, Realtek r8169 and VirtIO Net; additional Ethernet, Wi-Fi and USB network families are provided through the BSD Driver Bridge
Display	EFI GOP, framebuffer console, 63 virtual terminals, fbdev, DRM/KMS, EDID/DisplayID modes, Bochs BGA, VMware SVGA and VirtIO GPU 2D/3D paths
Input	PS/2 keyboard and mouse, Synaptics and Elan touchpads, USB HID, VirtIO Input and Linux input/event device interfaces
Audio	ALSA-facing PCM/control devices with HDA, AC97, USB audio and BSD bridge audio backends
USB	Hub and device enumeration, UHCI, OHCI, EHCI and xHCI hosts, HID, mass storage and audio; bridge packages add further host, gadget and device classes
Virtual machine devices	VirtIO PCI/MMIO block, SCSI, network, GPU, input, RNG, console and balloon devices, plus VMware storage and display devices
Firmware and buses	ACPI/ACPICA, Device Tree, EFI runtime, PCI/PCIe, MSI/MSI-X, I2C, SMBus, GPIO, SD/MMC bridge packages and firmware loading
Multiprocessing	x86 APIC/IOAPIC and AArch64 GICv3/PSCI bring-up, per-CPU state, reschedule IPIs, TLB shootdown and cross-CPU membarrier
Hardware services	ACPI power, battery and thermal data, CPU frequency control, RTC, RNG, TPM 2.0, watchdogs and LED/GPIO bridge interfaces
Board targets	Generic x86_64 PCs, generic AArch64 UEFI/virt systems, and build targets for Raspberry Pi 4 and Raspberry Pi 5
BSD Driver Bridge	Source-locked build packages for storage, Ethernet, Wi-Fi, USB, input, audio, firmware, platform, sensor and watchdog driver families

Linux ABI work is not finished. An inventory entry means that a route and implementation exist; it does not mean every corner case matches every Linux release. Hardware support has the same distinction: compiling a driver is not proof that it has been tested on every device it recognizes. The default x86_64 and AArch64 configurations differ where the hardware requires different drivers.

BSD Driver Bridge

The BSD Driver Bridge builds selected FreeBSD drivers from their upstream source files. EdgeOS supplies the kernel services expected by those drivers; device-specific state machines and recovery code remain upstream.

Imported files are kept under src/compat/freebsd/upstream/. Each package has a manifest that records its upstream revision, source paths, license data, capability requirements and a deterministic source digest. EdgeOS adaptation belongs in include/compat/freebsd/, src/compat/freebsd/ or a native frontend, not in the imported driver.

The bridge provides source compatibility, not FreeBSD binary module compatibility. Package and source checks reject missing files, unexpected changes and unsupported capability combinations. See docs/bsd-driver-bridge.md for the import and validation rules.

Build

The build requires GNU Make, Python 3, Clang/LLVM, LLD and NASM. The cross toolchains used by the Makefile must also be available in PATH.

x86_64

make defconfig
make -j"$(getconf _NPROCESSORS_ONLN)" kernel

Output: out/edgeos.bin

AArch64 UEFI

make arm64_defconfig
make -j"$(getconf _NPROCESSORS_ONLN)" arm64-kernel

Output: out/arm64/BOOTAA64.EFI

Configuration menus:

make menuconfig
make arm64-menuconfig

The Makefile also has targets for x86_64 initramfs media, AArch64 UEFI media, Raspberry Pi 4 and Raspberry Pi 5. An initramfs can be built from an existing root filesystem:

make INITRAMFS_SOURCE_DIR=/path/to/rootfs initramfs

Checks

Run both architecture builds after changing shared kernel code. The core repository checks are:

make kconfig-check
make syscall-inventory-check
make cross-arch-unity-check
make bsd-driver-build-plan-check
make bsd-driver-manifest-check

Focused unit targets for the scheduler, VFS, memory manager, network stack, filesystems and driver bridge are listed in the Makefile and under tools/tests/.

Source layout

arch/                       defconfig files
config/                     boot and driver configuration
include/                    kernel, UAPI and compatibility headers
src/arch/                   architecture mechanisms
src/kernel/                 shared process and kernel services
src/mm/                     memory management
src/vfs/ and src/fs/        VFS and filesystems
src/net/                    network stack
src/drivers/                native drivers
src/compat/freebsd/         BSD Driver Bridge and imported sources
tools/                      build tools, inventories and tests

The architecture ownership rules are documented in docs/kernel-layout.md.

License

Original EdgeOS code is licensed under the Mozilla Public License 2.0. Imported files keep their original licenses and notices. See NOTICE.md and the notices beside each imported source tree.

See CONTRIBUTING.md before submitting changes.