NetBSD

UNIX family tree.

NetBSD is a free and open source Unix family operating system, and, as of March 2019, available for 58 hardware platforms. Its design and Its advanced features make it ideal for a multitude of applications.

NetBSD has arisen as a result of the efforts of a large number of people whose goal is to produce an accessible and freely distributable Unix-like operating system.

History

The first version of NetBSD (0.8) dates from 1993 and stems from the BSDLite 4.3 operating system, a version of UNIX developed at the University of California Berkeley, and the 386BSD system, the first BSD ported to the Intel 386 CPU.

NetBSD takes its name from the 4BSD/Tahoe-Net/1 version of the BSDs, since the TCP/IP protocol, the most important protocol on the Internet, was developed on top of it. NetBSD, like FreeBSD, is derived from the latest version of BSD, 386BSD 0.1. The first release of NetBSD (version 0.8) saw the world on April 20, 1993.

Features

NetBSD is based on a wide variety of free software including, among others, 4.4BSD Lite from the University of California-Berkeley, Net/2 (Berkeley Networking Release 2) the MIT X Window System, and GNU software.

Currently NetBSD focuses on offering a stable, cross-platform, secure operating system. It is designed with the priority of writing quality and well-organized code, and also taking into account compliance with standards (POSIX, X/Open and others). relevant): proof of this good design is its wide portability.

This is a mature operating system, the product of years of development (the origins of BSD date back to 1977), and based on the UNIX sixth edition system.

Advantages

Some advantages over other operating systems:

• Special focus on code quality and portability. Ported to 56 architectures.
• He is often the pioneer in implementing new technologies (e.g. IPv6).
• High security and stability. It was used at NASA.
• File system BSD FFS (Fast File System), fast and reliable.
• Security: IPsec support.
• XEN Dom0: Native support of XEN virtual machines from version 3.0.

Portability

NetBSD has been ported to a large number of computer architectures, from VAX minicomputers to Pocket PC PDAs; NetBSD's motto is "Of course it runs NetBSD". The kernel and userspace for all supported platforms (comprising about twenty different processors) are compiled from a central, unified code tree managed by CVS.

Due to centralized source code management and a highly portable design, general functionality additions (not specific to a particular hardware) benefit all platforms immediately without the need to "port" them.

Device Drivers

Device driver development is also often hardware independent. That is, the driver for a PCI device will work regardless of whether the device is installed on an i386, Alpha, PowerPC, SPARC, or any other platform with PCI buses. Many NetBSD drivers also have code specific to a certain bus divided into bus subdrivers, allowing the same driver for a specific device to operate via different buses (eg ISA, PCI, PCMCIA...).

This platform independence greatly helps embedded system development, especially since the introduction of cross-compilation in NetBSD 1.6:

Cross compile

Starting with NetBSD 1.6, the complete toolkit of compilers, assemblers, linkers and others fully supports cross-compiling, allowing an entire NetBSD system to be compiled for one architecture from another system of a different (usually more powerful) architecture, even from different operating system (the cross-compilation framework supports any POSIX system).

Modular Portability Layer

The portability of NetBSD is due to its unique Modular Portability Layer (MPL, Modular Portability Layer). With MPL the device driver is completely isolated from the hardware platform, I/O instructions, interlocking, error recovery, even peripherals that use pseudo-DMA to write a RAM buffer with CPU copy-in and copy-out local are transparently handled at the controller layer. On the other hand, several embedded devices using NetBSD have not required additional development software other than the toolkit.

In other systems like GNU/Linux, in contrast, the driver code must be re-adapted for each new architecture. As a consequence, in recent efforts by NetBSD and Linux developers to port the system, NetBSD has taken 10% of the time of Linux to port to new hardware. The engineers who ported NetBSD to the SuperH processor took only six weeks; to port Linux it took three months. NetBSD was ported to the AMD64 platform in about a month, while Linux took about six months.

In 2005, as a demonstration of the portability and convenience of NetBSD for embedded applications, Technologic Systems, a vendor of embedded hardware systems, designed and demonstrated a kitchen toaster running on NetBSD.

Logo

The NetBSD logo, a large waving flag, was designed by Grant Bisset after several members of the NetBSD development team pointed out the old 1994 logo as unsuitable for an international project as it was inspired by the uprising of the American flag on Iwo Jima.

License

All NetBSD source code is released under the BSD license and its clauses 1,2,3 and 4. This makes it possible for anyone to use, modify and even sell NetBSD as long as they keep the acknowledgments.

On June 20, 2008, the NetBSD Foundation announced a transition to the two-clause BSD license, citing some concerns with UCB support of clause 3 and industrial applicability of clause 4.

NetBSD also includes the GNU development tools and other packages that are covered by the GPL and other open source licenses.

Pkgsrc

One of the most interesting NetBSD projects is their simple and powerful package system, pkgsrc. Since the NetBSD kernel is portable to many architectures, pkgsrc is a metasystem, that is, it downloads source code and compiles to produce the binaries. This package system works in a similar way to emerge, from the Gentoo Linux distribution. Pkgsrc is a simple way to have the latest versions of software such as Openoffice.org, KDE or Gnome, among many other programs.

Sun Microsystems has recently funded part of the development of pkgsrc. Currently pkgsrc is available for different flavors of Unix such as Irix, Solaris, FreeBSD, OpenBSD, in the list, in addition, Slackware Linux is included, although in principle it is possible to install it on any of the GNU/Linux distributions. DragonFlyBSD, another BSD distribution, has also adopted pkgsrc as its package system. This system created its last system update on September 25, 2005, which would correspond to version 5.1.