BareMetal
Operating system
From Wikipedia, the free encyclopedia
BareMetal is an exokernel-based single address space operating system (OS) created by Return Infinity.
| BareMetal | |
|---|---|
| Developer | Return Infinity |
| Written in | Assembly |
| Working state | Current |
| Source model | Open source |
| Initial release | 2008 |
| Latest release | 2025.04 / April 30, 2025[1] |
| Marketing target | HPCs, HTC, Cloud computing |
| Available in | English |
| Supported platforms | x86-64 |
| Kernel type | Exokernel, SASOS |
| Userland | Unknown |
| Default user interface | Command-line |
| License | BSD License[2] |
| Official website | www |
It is written in assembly to achieve high-performance computing with minimal footprint[3][4] with a "just enough operating system" (JeOS) approach.[5] The operating system is primarily targeted towards virtualized environments for cloud computing, or HPCs due to its design as a lightweight kernel (LWK). It could be used as a unikernel.
It was inspired by another OS written in assembly, MikeOS,[2] and it is a recent example of an operating system that is not written in C or C++, nor based on Unix-like kernels.[6]
Overview
Hardware requirements
Source:[7]
Supported devices
Source:[8]
- Bus - PCIe, PCI, xHCI
- Non-volatile storage - NVMe, AHCI (SATA), ATA, Virtio-Blk
- Ethernet - Intel 8259x 10-gigabit, Intel 8254x/8257x Gigabit, Realtek 816x/811x Gigabit, Virtio-Net
One task per core
Multitasking on BareMetal is unusual for modern operating systems. BareMetal uses an internal work queue that all CPU cores poll. A task added to the work queue will be processed by any available CPU core in the system and will execute until completion, which results in no context switch overhead.[9]
Programming
API
An API is documented[10] but, in line with its philosophy, the OS does not enforce entry points for system calls (e.g.: no call gates or other safety mechanisms).
C
BareMetal OS has a build script to pull the latest code, make the needed changes, and then compile C code using[11] the Newlib C standard library.[12]
C++
A mostly-complete C++11 Standard Library was designed and developed for working in ring 0.[13] The main goal of such library is providing, on a library level, an alternative to hardware memory protection used in classical OSes, with help of carefully designed classes.[14]
K
k for BareMetal:[15] a port of k edu from shakti[16] by Jack Andrews. At this stage, it is just a proof of concept and doesn't integrate the BareMetal file system.
Rust
A Rust program demonstration was added to the programs in November 2014, demonstrating the ability to write Rust programs for BareMetal OS.[17]
Networking
TCP/IP stack
A TCP/IP stack was the #1 feature request.[18] A port of lwIP written in C was announced in October 2014.[19]
minIP,[20] a minimalist IP stack in ANSI C able to provide enough functionalities to serve a simple static webpage, is being developed as a proof of concept to learn the fundamentals in preparation for an x86-64 assembly re-write planned for the future.
