iOS, formerly iPhone OS is the mobile operating system developed by Apple for the iPhone, iPod touch, and the iPad. It is derived from Mac OS X that he shared the foundations (XNU kernel hybrid based on Mach microkernel). iOS has four layers of abstraction, similar to Mac OS X: a layer "Core OS" layer "Core Services" layer "Media" and a coat Cocoa. The operating system takes up less than half a gigabyte (GB) of total memory capacity of the device.
This operating system had no official name before the release of iPhone software development kit (SDK) March 6, 2008. Until then, Apple was content to note that "iPhone runs OS X", an ambiguous reference to the operating system source iOS, Mac OS X. Only this time that Scott Forstall presented the internal architecture of the operating system, and then unveiled the name iPhone OS. The name was changed to June 7, 2010 iOS.
The development kit in question, available for Mac OS X, provides the tools necessary to create an application that can run on iOS. If you download and use free of charge, the publication of such applications requires to join the developer program Apple for the sum of $ 99 per year. The fact remains that this offer may be interesting for many developers, given the size of the market created by iOS.
Indeed, Apple has announced, at a musical event September 9, 2009, having sold 50 million iPhones and iPod Touch. For information, the 40 million devices in iOS had been exceeded only three months earlier, June 8, 2009. Moreover, the App Store portal, dedicated to the exposure of all third-party applications developed for that operating system, is often presented as a successful economic model: With a catalog of 100,000 applications which have been 3 billion downloads, the App Store has become in 18 months as a reference among the booths of mobile applications.
The software architecture of the iPhone is characterized by:
* The baseband: It may be regarded as a BIOS for the iPhone. So a firmware self dealing in real time all interactions with the communication devices of the device: Bluetooth, Wi-Fi and GSM . The baseband version is identified by a series of numbers format 00.00.00_G. Many versions of the component exist at present, and are different for each device running IOS. The baseband is usually updated at major updates of firmware. The evolution of different versions of baseband devices under iOS is detailed in this article.
* The BootLoader: This is part of baseband, whose primary role is to ensure the launch of the iPhone, control activation, and its compatibility with the SIM card inserted. To date, have been identified as two versions of BootLoader, the 3.9 used until the European release of the iPhone and the 4.6 which is used on all iPhones sold since release in Europe. However, it is very likely that many new versions are out in the meantime, without a broader community should be notified, because it is not possible for a user to know the BootLoader version of the aircraft, unless jailbreak "it (see below).
* Firmware: This is an internal software of the device, this time the responsibility for managing his party systems (screen, keyboard touch, etc..). It is identified by a number format XYZ, the first being the 1.0.0. The first number (X) denotes a major release of software, with significant extra features. The second number (Y) represents a minor update still providing some new features. The third (Z) denotes a simple update corrective bugs or performance optimization. Z is usually not written if it is zero, but X and Y are always written by convention (eg 2.0, 2.1, 2.0.1).
* The secpack: This is part of the flash memory device containing among others information on locking it. The Seckpack can be considered as a password: indeed, if a proper SeckPack BootLoader is provided at the launch, then the user has the option of using the baseband, and therefore the functionality of Internet and telephony.
The application support use on the iPhone and iPod touch is based on an ARM processor unlike the older versions used on Apple computers (PowerPC) or recent (Intel x86). In addition, iOS uses OpenGL ES API running on a dual-core 3D graphics card PowerVR. In short, applications developed for Mac OS X can not run on an iPhone or iPod Touch, all native applications are re-developed specifically for the ARM architecture and software components iOS.
iOS, purchase, includes twenty applications available by default, all developed by Apple. Their number may vary slightly depending on the device in question, due to minor hardware differences that separate the five devices with this operating system, and available to date. Most native applications have been made in order to work together, allowing them to communicate intelligently. For example, a telephone number can be selected within an email and saved in the directory.
In addition, one of these default applications provides access via an Internet connection to download platform App Store, which adds to the device additional applications developed by third parties, and validated by Apple .
Unlike some competitors, the iOS does not allow the execution of a third party application in the background. However multitasking for some of its native applications, for example it is possible to listen to music with the iPod application while browsing the Internet with the Safari application. This gap is partly filled now, however, with the arrival of version 3.0 which includes a system of notifications sent from the server from Apple. In addition, version 4, scheduled for release June 24, 2010, will remove this restriction.
See also iPod touch
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