BareMetal is an

exokernel Exokernel is an operating system kernel developed by the MIT Parallel and Distributed Operating Systems group, and also a class of similar operating systems. Operating systems generally present hardware resources to applications through high-lev ...

-based

single address space operating system In computer science, a single address space operating system (or SASOS) is an operating system that provides only one globally shared address space for all processes. In a single address space operating system, numerically identical (virtual memor ...

(OS) created by Return Infinity. It is written in

assembly Assembly may refer to: Organisations and meetings * Deliberative assembly, a gathering of members who use parliamentary procedure for making decisions * General assembly, an official meeting of the members of an organization or of their representa ...

to achieve high-performance computing with minimal footprint with a "just enough operating system" (

JeOS Just enough operating system (JeOS, pronounced "juice" according to SUSE) is a paradigm for customizing operating systems to fit the needs of a particular application such as for a software appliance. The platform only includes the operating syste ...

) approach. The operating system is primarily targeted towards

virtualized In computing, virtualization or virtualisation (sometimes abbreviated v12n, a numeronym) is the act of creating a virtual (rather than actual) version of something at the same abstraction level, including virtual computer hardware platforms, stor ...

environments for

cloud computing Cloud computing is the on-demand availability of computer system resources, especially data storage ( cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over mul ...

, or HPCs due to its design as a lightweight kernel (LWK). It could be used as a

unikernel A unikernel is a specialised, single address space machine image constructed by using library operating systems. A developer selects, from a modular stack, the minimal set of libraries which correspond to the OS constructs required for the appl ...

. 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

* AMD/Intel based 64-bit computer * Memory: 4 MB (plus 2 MB for every additional core) * Hard Disk: 32 MB

One task per core

Multitasking on BareMetal is unusual for modern operating systems. BareMetal uses an internal work

queue __NOTOC__ Queue () may refer to: * Queue area, or queue, a line or area where people wait for goods or services Arts, entertainment, and media *''ACM Queue'', a computer magazine * ''The Queue'' (Sorokin novel), a 1983 novel by Russian author ...

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 In computing, a context switch is the process of storing the state of a process or thread, so that it can be restored and resume execution at a later point, and then restoring a different, previously saved, state. This allows multiple processes ...

overhead.

Programming

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standa ...

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

system call In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, acc ...

s (e.g.: no

call gate A call gate is a mechanism in Intel's x86 architecture for changing the privilege level of a process when it executes a predefined function call using a CALL FAR instruction. Overview Call gates are intended to allow less privileged code to ca ...

s 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 the

Newlib Newlib is a C standard library implementation intended for use on embedded systems. It is a conglomeration of several library parts, all under free software licenses that make them easily usable on embedded products. It was created by Cygnus S ...

C standard library.

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

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.

Rust Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH ...

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

TCP/IP The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...

stack was the #1 feature request. A port of

lwIP lwIP (lightweight IP) is a widely used open-source TCP/IP stack designed for embedded systems. lwIP was originally developed by Adam Dunkels at the Swedish Institute of Computer Science and is now developed and maintained by a worldwide networ ...

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.

References

External links

*
BareMetal OS

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discussion forum Free software operating systems Hobbyist operating systems Microkernels Software using the BSD license Assembly language software {{Operating-system-stub