BareMetal


BareMetal is an exokernel-based single address space operating system created by Return Infinity.
It is written in assembly to achieve high-performance computing with minimal footprint with a "just enough operating system" approach. The operating system is primarily targeted towards virtualized environments for cloud computing, or HPCs due to its design as a lightweight kernel. It could be used as a unikernel.
It was inspired by another OS written in assembly, MikeOS, and it is a recent example of an operating system that is not written in C or C++, nor based on Unix-like kernels.

Overview

Hardware requirements

Source:

Supported devices

Source:
  • Bus - PCIe, PCI, xHCI
  • Non-volatile storage - NVMe, AHCI, 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.

Programming

[API]

An API is documented but, in line with its philosophy, the OS does not enforce entry points for system calls.

C">C (programming language)">C

BareMetal OS has a build script to pull the latest code, make the needed changes, and then compile C code using the Newlib C standard library.

[C++]

A mostly-complete C++11 Standard Library was designed and developed for working in ring 0. 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.

K">K (programming language)">K

k for BareMetal: a port of k edu from shakti by Jack Andrews. At this stage, it is just a proof of concept and doesn't integrate the BareMetal file system.

Rust">Rust (programming language)">Rust

A Rust program demonstration was added to the programs in November 2014, demonstrating the ability to write Rust programs for BareMetal OS.

Networking

TCP/IP stack

A TCP/IP stack was the #1 feature request. A port of lwIP written in C was announced in October 2014.
minIP, 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.