NonUI builds

This is a documented list of known NonUI builds, used by Apple workers in California to do engineering tests on prototype devices and also by factory workers on production devices during manufacturing. These "factory firmwares" are based on production iOS firmware, but are adapted for internal engineering tests, development and debugging.

The name "NonUI" (Non-User Interface) refers to how a majority of applications in these builds are accessible via command line interace. The applications which do use a graphical user interface can be launched through SwitchBoard, a minimal version of SpringBoard. Unlike production iOS firmwares, factory firmwares have the following differences: Factory firmwares are distributed via internal "restore bundles", which can only be restored on devices using internal restore software such as PurpleRestore. Release and factory firmware "restore bundles" have the same directory structure (bootloaders, kernel, restore ramdisk, update ramdisk and root filesystem), but can also include other files specific to internal development builds of iOS.
 * DEVELOPMENT fused bootloaders in  and.
 * FACTORY fused SEP firmware in
 * DEVELOPMENT fused kernelcache with more symbols (located in  on the filesystem), and with individual kexts in.
 * DEVELOPMENT dyld_shared_cache in.
 * DEBUG fused baseband firmware in.
 * Skankwerk (gear) logo image file in.
 * folder, which the hierarchy inside get priority over hierarchy in.
 * No SpringBoard, requires the use of daemons to launch SwitchBoard.app as a multi-app launcher instead.
 * and subfolders contain many UNIX command line utilities.
 * SSH daemon is pre-installed as dropbear, can be connected to over usb
 * Boot loader passes arguments to kernel (unlike RELEASE boot loaders as of iOS 5.0) which makes it easy to disable AMFI
 * It has some additional Private Frameworks in  for internal GUI apps and command line utilities.
 * Most internal applications require the use of SkankKit (replacement for UIKit in nonUI firmwares) to produce special layers such as text on the framebuffer.

= Some interesting facts about factory firmwares = Production iOS 1.x to 6.x skeuomorphism design is also present on 1.x to 6.x factory firmwares, but seems really more excessive than production ones. For example, the "skankwerk" boot logo represents a real gear and many GUI icons are realistic or simply photos of real life things (especially in Operator). For newer versions, production iOS 7.x to 9.x flat design is mostly used in 7.x to 9.x factory firmwares. For example, the new "skankwerk" boot logo is a flat, simple white gear. Some newer internal applications like Earthbound also use a "flat" design. = iPhones =
 * Design: Apple seems to use the same GUI design from the production firmware to the factory one.
 * Other: The "skank" word is used to name multiple elements of factory firmwares. For example, there is "skankphone", "skankbattery" (the green battery shown in SwitchBoard), "skankwerk" logo, "skankkit" framework, "purpleskank" (used by BurnIn) and most likely others. The "skank" word seems to be a reference to "Skunkworks" projects, which are secrecy projects that are usually innovative. Read more about "Skunkworks" on Wikipedia.

iPhone 12 Pro Max
= iPads =

iPad Pro 12.9 (5th generation)
=iPods=