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OSx86 (from Mac OS X and x86) is a collaborative hacking project to run the Mac OS X computer operating system on non-Apple personal computers with x86 architecture and x86-64 compatible processors. The effort started soon after the June 2005 Worldwide Developers Conference announcement that Apple would be transitioning its personal computers from PowerPC to Intel microprocessors.
A computer built to run this type of Mac OS X is also known as a Hackintosh, a portmanteau of the word "hack" and the name of Apple's main brand of computers, Macintosh. Hackintoshed notebook computers are also referred to as "Hackbooks".
The Apple software license does not allow Mac OS X to be used on a computer that is not "Apple-branded". The legality of this form of tying is disputed by companies such as Psystar, Bizon computer, PearC and MacPC who have attempted to release products using Mac OS on non Apple-machines. However, while the methods Apple uses to prevent Mac OS X from being installed on non-Apple hardware are protected from commercial circumvention in the United States by the DMCA, specific changes to the law regarding the concept of jailbreaking has thrown such and similar circumvention methods into a grey area when carried out by end-users for personal use.[not in citation given]
Apple does not authorize the use of the Mac OS on any x86 PC other than the ones it has developed itself. The company used technical means (although not the Trusted Platform Module, or TPM, as has been widely mis-reported ), to tie Mac OS to the systems it distributed to developers after announcing its switch to Intel's chips.
The Mac OS X EULA forbids installations of Mac OS X on a "non-Apple-branded computer". On July 3, 2008, Apple filed a lawsuit against Psystar Corporation for violating this restriction, among other claims. Apple claimed Psystar "violated the Digital Millennium Copyright Act (DMCA) by dodging copy-protection technologies Apple uses to protect Mac OS X." Apple employs technological protection measures that effectively control access to Apple's copyrighted works [...] Defendant has illegally circumvented Apple's technological copyright-protection measures." Specifically, Apple charged Psystar with acquiring or creating code that "avoids, bypasses, removes, descrambles, decrypts, deactivates or impairs a technological protection measure without Apple's authority for the purpose of gaining unauthorized access to Apple's copyrighted works." This brief revealed that Apple considers the methods that it uses to prevent Mac OS X from being installed on non-Apple hardware to be protected by the Digital Millennium Copyright Act (DMCA).
On November 13, 2009, the court granted Apple's motion for summary judgment and found Apple's copyrights were violated as well as the DMCA when Psystar installed Apple's operating system on non-Apple computers. A hearing on remedies was set for December 14.
On January 14, 2009, the Gadget Lab site of Wired Magazine posted a video tutorial for installing Mac OS X on an MSI Wind netbook, but removed it following a complaint from Apple. Textual instructions remain, but include an EULA violation disclaimer.
On May 15, 2012, the case Apple vs. Psystar Corporation finally ended. The court ruled that Psystar has "violated Apple's exclusive reproduction right, distribution right, and right to create derivative works.", putting an end to the case.
Efforts to run Mac OS X on non-Apple hardware utilized leaked copies of pre-release software. On June 6, 2005 Apple announced the availability of a Developer Transition Kit. This kit was made available to registered developers at a cost of $999. The first patches circumvented the Trusted Platform Module (TPM) that was included on the motherboard of the Developer Transition Kits. The TPM was required by the Rosetta technology that allowed software compiled for the PowerPC architecture to run on Intel-based architecture. Removing this requirement allowed Mac OS X to be installed on non-Apple computers. Rosetta also required microprocessors that included SSE3 instructions. Patches were released to the community which emulated these instructions with SSE2 equivalents and allowed the installation on machines without SSE3 support, although this produced a performance penalty. Being beta software, many updates followed its release.
On January 10, 2006, Apple released Mac OS X 10.4.4 with the first generation of Intel-based Macs, the iMac and the MacBook Pro. These machines used Extensible Firmware Interface (EFI) platform firmware instead of the older style BIOS found on most x86 motherboards. On February 14, 2006, an initial "hack" of Mac OS X v10.4.4 was released on the Internet by a programmer with the pseudonym crg92. Within hours Apple released the 10.4.5 update, which was patched again by the same author within two weeks. On April 3, 2006 Apple released their 10.4.6 update and again patches were released within two weeks that allowed users to install most of this update on non-Apple computers, although this did not include the updated kernel in 10.4.6. In June, the hackers released the 10.4.7 Mac OS X update for non-Apple computers using the 10.4.4 kernel.
Up to the release of the 10.4.8 update, all OSx86 patches used the 10.4.4 kernel with the rest of the operating system at version 10.4.8. However, the newer frameworks relied on the newer kernels and this led to users of 10.4.8 encountering many problems. Apple also started making more use of SSE3 instructions on their hardware making it even more difficult for users with CPUs supporting only SSE2 (such as older Pentium 4's) to get a fully compatible system running.
Two programmers, working under the pseudonyms Mifki or Vitaliy and Semthex, released new kernels by starting with the open source XNU tree and applying patches necessary to run the kernel on non-Apple hardware. Mifki's goal was to release the kernel with as few patches as possible, able to run on close-to-Apple hardware. Semthex's goal was to make his kernel more compatible with older design hardware with the omission of some crucial features.
Both kernels allowed most of the updated kernel extensions/frameworks to work, making properly configured PCs operate more like genuine Apple computers. While Mifki has only updated his kernel once, Semthex updates it regularly and added AMD, VMware and SSE2-support in later versions. Semthex released his hacked kernel source code on his webpage. On December 24, 2006 he also released the latest patches for the SSE3 kernel as a diff file for his original source tree as a Christmas present to the community. The SSE2 emulation that Semthex developed with Rufus was the first fully complete emulation of all SSE3 instructions to be presented to the OSx86 community. The previous SSE2 emulation was incomplete, only emulating 3 of the available SSE3 instructions, and very inefficient compared to the new emulator. The new emulator enabled even SSE2 OSx86 users to run SSE3 based applications such as iTunes 7 and most 3D programs.
In the early days of 10.4.8, an Intel-SSE3 only install DVD was released by JaS, which included Vitaliy's and Semthex's kernel. A few weeks later, a hacker calling himself tubgirl released an AMD-SSE3 install DVD. With Semthex's successful completion of the SSE2 Kernel, JaS released an SSE2-SSE3 universal DVD and announced his retirement from hacking Mac OS X after seven successful DVD releases. However, on August 9, 2008, JaS released yet another distribution featuring both a client and server version of Mac OS 10.5.4.
As early as Mac OS X v10.5 build 9A466 the community has maintained a version of Leopard that can run on non-Apple hardware. A hacker by the handle of BrazilMac created one of the earliest patching processes which made it convenient for users to install Mac OS X onto 3rd party hardware by using a legally obtained, retail version of Apple Mac OS X. It was utilizing the BrazilMac patch that many effortless distros of Mac OSx86 came to fruition. Five of the most popular builds go by the name JaS, Kalyway, iATKOS, iPC and iDeneb - although more recently these builds are on the way out as the Boot-132 method (described below) gains popularity. However, all of these compilations rely on the work of kernel hackers made by Lorem (build 9A466), SynthetiX (builds 9A499, 9A527 and 9A559), ToH (builds 9A581, 9B13 and 9B18) and more recently a group calling themselves StageXNU (now called Voodoo) (Darwin 9.4.0). Their contributions trickled down into the various Mac OSx86 installers, readily available on the internet. There continue to be refined and updated builds released, not just to maintain compatibility with Apple releases but an ever increasing number of third party components. The OSx86 community has been quick to make the necessary modifications to enable Apple's latest releases to run on non-Apple hardware. Within hours of Leopard's release, an AMD/Intel SSE2/3 Kernel Patcher was created which removed the HPET requirement from an original untouched mach_kernel file, a core component of the Mac OS.
When "Snow Leopard" was released, Russian hacker netkas created a version of Chameleon which can boot Mac OS X v10.6. The main problem was that many people were forced to modify DSDT or use kexts due to some specific issues. As soon as possible modbin and dmitrik released test versions of kernel that allow to boot Snow Leopard on AMD machines. Stable XNU kernels for v10.6 were released by Qoopz and Pcj. There are some popular builds based on Retail by the name Universal (Intel only), Hazard, and iAtkos. Since v10.6.2 Nawcom, Qoopz, and Andy Vandijck have been working on Legacy kernel for unsupported CPUs.
When Apple released the Developer Preview 1, a Russian Hackintosh developer usr-sse2 was the first who created a method to install Lion. The method consists of deploying Mac OS X v10.7 image on a flash drive, and booting from it via XPC UEFI Bootloader (See DUET below). After some changes were made to the Chameleon source code, booting of Lion was possible with an updated version of Chameleon. After a while Dmitrik also known as Bronzovka had luck with creating a kernel which supported AMD systems; its development is still ongoing.
Shortly after the release of Developer Preview 1, some unknown developers managed to install this version of OSX to their PC by using a modified version of the Chameleon Bootloader. This version was released via the main project starting at version r1997 to the general public. Due to the problems sourced during the Lion era,[clarification needed] other ways of installing and required patches were never made public, which leaves the scene in an unknown state towards Mountain Lion.
Since the retail release of Mountain Lion several users have reported successful setups using installers purchased from the Mac App Store, along with updated versions of Chameleon and other tools.
Extensible Firmware Interface (EFI) is a specification that defines a software interface between an operating system and platform firmware. Since this method generally does not require copying or modification of Mac OS X, it is the considered to be (despite being untested in courts) the legal way of installing Mac OS X on non-Apple computers.
In early November 2007, a group of hackers (fronted by a Russian hacker known as Netkas), using an already modified boot-132 source root from David Elliot (also known as dfe), developed a method of emulating an EFI environment using a specially modified Darwin boot loader. In practical terms, this meant that regular PCs meeting a minimum set of hardware requirements could now be "seen" as real Macintosh computers by the OS, allowing the use of unmodified, "stock" Apple kernels (as long as the CPU supports it) and thus giving a more transparent and reliable operation. Several methods for real world deployment of this innovative solution have arisen all around the Internet. An explanation of this achievement along with a usage guide was provided by the website DigitMemo.com.
True EFI emulation was a highly sought after asset for the OSx86 community. Previous efforts based upon Apple's open source Darwin Project and Hackintosh gurus allowed users to use Mac OS X on normal PCs, with patched kernels/kernel modules which simply bypassed EFI. Using the EFI patch, a Hackintosh could boot off "vanilla" (unmodified) Mac OS X kernels and use vanilla kernel extensions. This not only allowed the system to be compatible with future system updates, but also offered increased stability. This method also circumvents one aspect of Apple's End User License Agreement, which states that the modification of non-open Source components of the OS is forbidden.
In mid-2008, a new commercial product, EFi-X, was released that claims to allow full, simple booting off official Leopard install disks, and a subsequent install, without any patching required, but this is possibly a repackaging of Boot-132 technology in a USB-attached device. Rebel EFI is another commercial product that also seems to use open source software.
It was thought that Windows 7 support of EFI would result in PC motherboards replacing BIOS with EFI. MSI announced the Efinity mainboard in early 2008. As of 2011, EFI-based computers have entered the market, however none can natively boot Mac OS X due to the lack of a HFS+ driver in the EFI implementation.
Boot-132 is a boot loader provided by Apple for loading the XNU kernel. In mid-2008, a new modified BOOT-132 came on to the scene. This method allows users to conduct the Leopard-based OSx86 installation using a stock, retail purchased copy of Mac OS X Leopard and eradicates the necessity of a hacked installation like JaS or Kalyway (mentioned previously). The Boot-132 boot loader essentially preloads an environment on the system from which Leopard can boot and operate. The boot loader stores the necessary files (kext files) in a .img collection or simply a folder. The luxury of this new installation method includes the ability to boot and install from a retail Leopard DVD and update straight from Apple without breaking the DMCA. The only possible problem here is that it breaks the Mac OS X EULA.
The boot loader behaves like the linux kernel: one can use an mboot-compatible (a patched syslinux was used for the hack) boot loader which tells boot-dfe about the .img file (the ramdisk or initrd, as it's known by linux users), and boot-dfe will then use the kexts (or mkext) from it. This new boot-dfe has been tested with the retail Leopard DVD, and it can boot, install, and run Leopard without having to build a modified DVD.
Since the early developer builds of Mac OS X v10.6, members of the OSx86 community had been booting the new operating system using yet another boot loader called PC EFI provided by Russian hacker Netkas or the boot loader of the Voodoo team Chameleon. Chameleon is based on David Elliot's BOOT-132. The bootloader supports ACPI, SMBIOS, graphics, ethernet, and some other injections. It allows to boot up Mac OS X on non-Macintosh hardware. Chameleon supports a lot of AMD as well as Nvidia Graphics Cards. There are a lot of branches of it by different developers. Chameleon is currently in the 2.1 development state.
Based on DUET, rEFIt.
In March 2007, the OSx86 community made some significant progress with the development of a Live DVD. The Live DVD allows booting to a working system with Mac OS X v10.4.8.
On January 2, 2009, InsanelyMac's Live DVD team published a new method by which a Mac OS X v10.5.x Live DVD could be produced, allowing users to boot a fully working Mac OS X desktop from a DVD or USB flash drive. The method was more reliable than previous methods because it manipulated Apple's existing Netboot and Imageboot functionalities and behaved as if the system were running off a network disk. It was easier to produce; requiring only a single script to be added to an existing installation. Distributions of the live DVD have been made since its inception. Since then, it is notable that this method has been shown to work on normal Apple Mac hardware.
From OS X version Lion, the Live DVD/USB should be even easier to implement.
It is also possible to run the Mac OS as a virtual machine inside of other operating systems installed on standard PC hardware, by using virtualization software such as Oracle's VirtualBox  (though this is not officially supported by Oracle). This method typically utilizes some of the modified OS software listed above to perform the actual install.