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// Workers AI · dad joke modeWhat did BareMetal say to its date? You're a-weld above the rest.

From Wikipedia, the free encyclopedia
BareMetal
DeveloperReturn Infinity
Written inAssembly
Working stateCurrent
Source modelOpen source
Initial release2008; 18 years ago (2008)
Latest release2025.04 / April 30, 2025; 16 months ago (2025-04-30)[1]
Marketing targetHPCs, HTC, Cloud computing
Available inEnglish
Supported platformsx86-64
Kernel typeExokernel, SASOS
UserlandUnknown
Default
user interface
Command-line
LicenseBSD License[2]
Official websitewww.returninfinity.com

BareMetal is an exokernel-based single address space operating system (OS) created by Return Infinity.

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

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Hardware requirements

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Source:[7]

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

Supported devices

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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

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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

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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).

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]

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 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.

A Rust program demonstration was added to the programs in November 2014, demonstrating the ability to write Rust programs for BareMetal OS.[17]

Networking

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TCP/IP stack

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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.

References

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  1. ↑ Seyler, Ian. "Releases · ReturnInfinity/BareMetal". BareMetal OS GitHub repository. Retrieved May 19, 2025.
  2. 1 2 Voorsanger, Conrad (June 2, 2011). "Interview With Baremetal OS' Ian Seyler". OSNews. Retrieved May 26, 2014.
  3. ↑ Adams, David (July 14, 2010). "BareMetal OS". OSNews. Retrieved May 26, 2014.
  4. ↑ Benchoff, Brian (May 27, 2011). "64-bit OS written entirely in assembly". Hack A Day. Retrieved May 26, 2014.
  5. ↑ Seyler, Ian. "Return Infinity (home page), The BareMetal advantage". Return Infinity. Retrieved February 2, 2015.
  6. ↑ Smith, Jesse (July 19, 2010). "DistroWatch Weekly, Issue 363". DistroWatch. Retrieved May 26, 2014.
  7. ↑ "BareMetal OS Requirements". Return Infinity (archived copy at Wayback Machine). Archived from the original on September 6, 2014. Retrieved September 6, 2014.
  8. ↑ Seyler, Ian. "Supported Hardware". BareMetal OS GitHub repository. Retrieved May 19, 2025.
  9. ↑ "BareMetal OS Queue". Retrieved April 28, 2015.
  10. ↑ Seyler, Ian. "API documentation". BareMetal OS GitHub repository. Retrieved June 26, 2015.
  11. ↑ Seyler, Ian (January 17, 2014). "Newlib build script". BeareMetal OS Google Group. Retrieved February 2, 2015.
  12. ↑ Seyler, Ian. "newlib.sh". Build scripts for BareMetal OS and its related utilities, GitHub repository. Retrieved February 2, 2015.
  13. ↑ Lodyagin, Sergei (November 17, 2013). "Bare C++ library". BeareMetal OS Google Group. Retrieved February 2, 2015.
  14. ↑ Lodyagin, Sergei. "The Bare C++ library". The Bare C++ library GitHub repository. Retrieved February 2, 2015.
  15. ↑ Andrews, Jack (December 10, 2024). "ReturnInfinity/kbm: k for BareMetal". BeareMetal OS port of k edu. Retrieved May 19, 2025.
  16. ↑ Whitney, Arthur. "shakti". k edu at shakti. Retrieved May 19, 2025.
  17. ↑ Seyler, Ian. "Add Rust example". BareMetal OS GitHub repository (legacy version). Retrieved March 18, 2018.
  18. ↑ Seyler, Ian (August 22, 2013). "TCP/IP". BeareMetal OS Google Group. Retrieved February 2, 2015.
  19. ↑ Seyler, Ian (October 31, 2014). "BareMetal and lwIP". BeareMetal OS Google Group. Retrieved February 2, 2015.
  20. ↑ Seyler, Ian. "minIP - A minimalist IP stack written in ANSI C". BareMetal OS GitHub repository. Retrieved May 24, 2017.
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