What is the latest IOS version for my iPhone or iPad: how to find out and where to download. Overview of the IOS11 operating system of the IOS operating system as well

Since popularity apple products It grows every day, more and more often you can hear the question: "IOS - what is it?" In fact, this is an operating system originally released in 2007 for iPhone and having settings to control the touch screen. Subsequently, it was expanded to support other devices and used on iPad and Apple TV. Unlike Windows Phone And Android, the manufacturer did not provide a license to use it on third-party devices. That is why this circumstance should be taken into account, speaking of iOS (how to install it on a smartphone or tablet).

The user interface of this OS is based on the concept of direct manipulation using multitouch. Management consists of a cursor, switch and buttons. Answering the question "iOS - what it is," it should be noted that this platform is derived from OS X and based on a similar basis. Thus, this is an operating system on the Unix kernel.

Apple provides important updates for OS approximately once a year, download which is possible using the iTunes service (starting with iOS Beta 2). The most new version of the operating system is 6.0, released by the nineteenth of September 2012. She offered users more than 200 new features, including new Apple Passbook, maps and full Facebook integration.

The screen interface (known as SpringBoard) displays icons and widgets at the bottom of the screen, where users can fix the most frequently used applications. At the top is which displays the current data as time, the battery level and signal strength.

Starting from version 3.0, the Spotlight search function was available on the left side of the screen. It allows users to find music, applications, email, contacts, messages, reminders, calendar of events and similar files.

In iOS 4 or later versions, users have the ability to set the image as the background of the main screen. This feature is available only in the third generation of devices or newer - with iPhone 3GS and iPod Touch 3. To iPad, however, this feature has been available since its output with the firmware 3.2.

When you try to explain in detail, iOS is what it is, it is impossible not to mention the Siri application. It is an intelligent personal assistant responsible for user voice commands. With it, you can perform various tasks, such as a set of numbers or text, launch applications, search on the Internet and so on.

Siri is currently available only on 5, iPod Touch. fifth generation, iPad mini, and ipad third and fourth generation.

Answering the question "iOS - what it is," it is impossible not to recall such a phenomenon like a jailbreak of Apple devices. Since the first release of the platform, it has become the subject of various hacks in order to add functionality that is not allowed by the manufacturer. Gradually, the common motives for the jailbreak changed. Users resort to it for various reasons, including to gain access to the file system, setting custom topics and modifications to the SpringBoard device. On some devices, the jailbreak also allows you to establish alternatives for example, Android and other Linux distributions.

iOS is the most simple operating system in terms of interaction with it inexperienced user, and this is one of the main reasons for the popularity of iPhone and iPad among absolutely all categories of the population. Almost any user can solve the problems encountered in the IOS software environment and even produce independently.

What is iOS and what types of updates are there

So, iOS is a software shell that controls iPhone or iPad hardware modules. The main advantage of this operating system is that the manufacturer of mobile gadgets - Apple is produced. In addition, third-party developers are also focused on a rather narrow range of devices, and this means almost complete absence of any compatibility issues, the choice of software version and its installation.

Another important nuance - Apple spreads its operating systems for free, without any hidden conditions (necessary subscriptions for products or services, the availability of paid previous versions, etc.). That is, you can download the up-to-date version of the firmware for your device from the official site, without risk, install a pirated copy with malicious software.

Apple releases 3 species iOS updates:

1. Official (final).

2. Beta versions for registered developers.

3. Beta versions for ordinary users registered in.

We told more about all types of IOS updates.

How to find out which version of iOS is installed on the iPhone or iPad at the moment

To find out which system controls the device in this moment, you need to go to the menu " Settings → Maintenance → About this device " and pay attention to the string " Version".

To check the availability of iOS updates for this device, return to the previous menu " Settings → Main " , choose the item " Software Update" And wait for data download.

The reasons for which updates may not appear on the iOS device are described.

How to install a new (last) iOS on your iPhone or ipad

The easiest way is to reflash the iPhone "by air". To do this, just go to the section mentioned above " Settings → Maintenance → Software Update", press the button " Download and install ». In this case, all available data will be saved on the device. It is important to remember that the installation of iOS "By air" in no case cannot be carried out if you have a jailbreak on the device.

To fully reinstall iOS via iTunes, you will need to perform a slightly more complex algorithm of actions, which is described in detail in the material. This will require an actual version of IOS for a specific iPhone or iPad.

Where to download the latest IOS firmware iPSW files for any iPhone or iPad

Apple does not allow you to install outdated versions of the operating system on your mobile devices (i.e., roll back or lower the IOS version), so only the last firmware released for it will be available for each gadget.

• For iPhone 2G, the last possible firmware for installation is iOS 3.1.3;
• iPhone 3G - iOS 4.2.1;
• iPhone 3GS - iOS 6.1.6;
• iPhone 4 - iOS 7.1.2.;
• iPhone 4S - iOS 9.3.5;
• iPhone 5, iPhone 5C - iOS 10.3.3.;
• iPhone 5S - iOS 12.2.;
• iPhone 6, iPhone 6 Plus - iOS 12.2.;
• iPhone 6S, iPhone 6S Plus - iOS 12.2.;
• iPhone SE - iOS 12.2.;
• iPhone 7, iPhone 7 Plus - iOS 12.2.;
• iPhone 8, iPhone 8 Plus - iOS 12.2.;
• iPhone X - iOS 12.2.;
• iPhone XR - iOS 12.2. ;
• iPhone XS - iOS 12.2. ;
• iPhone XS Max - iOS 12.2. ;
• iPod Touch 2G - iOS 4.2.1;
• iPod Touch 3G - iOS 5.1.1;
• iPod Touch 4G - iOS 6.1.6;
• iPod Touch 5G - iOS 9.3.5;
• iPod Touch 6G - iOS 12.2.;
• iPad 1 - iOS 5.1.1;
• iPad 2 - iOS 9.3.5;
• iPad 3 - iOS 9.3.5;
• iPad 4 - iOS 10.3.3.;
• iPad MINI 1 - iOS 9.3.5;
• ipad mini 2 - iOS 12.2.;
• iPad mini 3 - iOS 12.2.;
• ipad mini 4 - iOS 12.2.;
• iPad Air 1 - iOS 12.2.;
• iPad Air 2 - iOS 12.2.;
• iPad Air 2 - iOS 12.2. ;
• 9.7-inch iPad Pr. — iOS 12.2. ;
• 10.5-inch iPad Pro - iOS 12.2.;
• 11-inch iPad Pro - iOS 12.2. ;
• 12.9-inch iPad Pro - iOS 12.2.;
• iPad 2017 - iOS 12.2.;
• iPad 2017 - iOS 12.2. .

All necessary IPSW files for installing iOS can be downloaded from Apple official website by links placed

iOS - operating system (OS) for mobile devices issued by Apple in 2007. Unlike competing systems, only for various Apple brand mobile devices.

The main competitor is the OS from google companies. BUT B. lately These systems are increasingly similar to each other, adopting positive aspects of each other. Android, looking at iOS, becomes closer to users: here refers to both the simplicity and convenience of the "out of the box" and aesthetics of the interface. IOS in turn increases functionality and expands the possibilities of an individual setting.

Advantages of IOS.

Application Quality (AppStore)

The AppStore is an online iOS application store created by Apple in 2008.

Due to the fact that App Store. A strict application tolerance tolerance filter to the device can be installed only for truly high-quality applications. Most of the applications are paid due to the fact that the developers invest a lot of effort into development and testing and do not want to lose their customers at all and go down in the ranking, releasing the crude product.

Simple update

The transition from the release release on the OS release is carried out with one click and available immediately after the release and publication of the new update. At the same time, the need to update the user will notify the device itself. Unlike competing platforms, iOS supports devices issued for more than a year ago, thereby

does not make its customers acquire a new more powerful gadget, after the release of the new software.

Application updates are also carried out with one click, and in the settings you can set automatic loading and installing updates, after which you can be sure that your programs will always be up-to-date.

The best applications are published in the AppStore first

Many developers prefer to first release the application on the iPhone, and only after some time write an analogue under Android and Windows Phone. This is due to a qualitative development environment and convenient tools to create new applications.

Unified ecosystem

Apple mobile devices ecosystem (i.e. integration or interaction of various gadgets) is the most developed on the market. Their optimization is amazing, because the company also produces hardware, and the software part itself. This means that the operating system is maximally optimized for a specific device. A set of devices associated with an Apple ID account allows you to synchronize the data with each other, making the job easier and more productive.

Now you do not need to think about how to send information from one gadget to another, you just continue to work. Because access to your documents have all your devices.

Comfortable and easy to master interface

Taking any apple apparatus in hand, you will know how to use it. This became possible thanks to an intuitive interface that was created in such a way that he could easily learn each. All embedded applications are located on the home screen, the share of a second to take a glance at the screen and learn the weather, news, time and more.

Reliability

According to Strategy Analytics, Apple technician shows more than 2 times greater reliability compared to the devices of its competitors.

Safety

Achieved due to the closure of the platform, thanks to

you can forget about such technological concepts as "computer viruses".

But protection is provided not only from virtual attacks, protect your device from thieves will help the "Find iPhone" function and fingerprint scanner (Touch ID).

And this is not the entire list of system merits. The list of disadvantages is much more modest.

Disadvantages of IOS.

No universal system

Yes, the security has to pay: you will not be able to install the system to the device of another manufacturer, you will not be able to add new feature Or expand the possibilities without violating the User Agreement.

Restricting File Transfer via Bluetooth

Having on the board Bluetooth, the iPhone cannot transfer the file to the device of another manufacturer, but this deficiency is easily solved by sending the file to the "cloud".

Closed file system

The manufacturer took care of the systematization of files on the device, but not to all users like it.

Paid applications, music and films

Many consider it a disadvantage, but isn't it for the work of developers and authors you do not need to pay?

Thus, the system boasts convenience, stability, safety and ease of use, which is quite enough for many users.

IOS 7 against Windows Phone 8

Federal Agency for Education of the Russian Federation

State Educational Institution of Higher Professional Education

South Ural State University

Faculty "Instrument-making"

Department "Information and measuring equipment"

IOS operating system

By discipline

Computer science

Introduction

Computers closely entered our usual world. The computer cannot exist without the operating system. OS provides absolutely all the operation of the computer, whether it is a powerful server or a small phone in your pocket. Therefore, the OS topic in our time is very relevant and therefore I chose it. The analysis conducted by me will help to see how one of the IOS is one of the most popular in our time, as well as compare it with other OS.

Figure 1 - IOS logo

1. What is iOS?

iOS (until June 24, 2010 - iPhone OS) - Mobile operating system developed and manufactured by the American company Apple. Unlike Windows Phone and Google Android, only manufactured by Apple devices. Was released in 2007. Originally - for the iPhone and iPod Touch, later - for devices such as iPad and Apple TV.

All screen space consists of four components:

Work Screen (or Home Screen) - accommodates 16 icons of various custom purposes: Mail, calendar, photos, contacts, notes, clock, calculator, camera, settings, App Store, etc.

Row Dock. Located at the bottom of the working screen, consists of four elements.

Spotlight navigation panel with work screens and search - bottom screen

Status bar Status Bar. - The upper right corner of the screen - displays the network signal level, EDGE, 3G, Wi-Fi, Bluetooth, battery charge indicator, alarm status, music playback and tty.

2. The history of the appearance of iOS

Figure 2 - Desktop iOS 1

The first version of the mobile operating system was built on the same Unix core as Mac OS X. Apple Head Steve Jobs, representing the first iPhone on the presentation, called the iPhone OS ported Mac OS on new smartphone. But from the first minutes of the presentation it became clear that the differences would be colossal. Whatever innovative iPhone at the time of the presentation, its functionality is extremely limited. Little familiar functions have now been implemented in the first version of the Operations:

· Basic interface

· Multitouch gestures

· IPod music app

· Safari browser

· Synchronization with iTunes.

In updates appeared

· Web applications on the home screen

· Change the location of the icons

· Keyboard with multitouch support

· ITunes Music Store

In other words, even some familiar features of ordinary phones were absent in the first version of the operating system, such as, for example, a voice recorder, video recording, loading your own ringtones, search for contacts, sending MMS No background pattern in the menu and others. Applications on the iPhone did not exist in principle.

Despite this, the user interface together with sensory control using a capacitive type screen was truly revolutionary.

Figure 3 - Basic functions

Figure 4 - Windows Mobile 6 on smartphones 2006-2007 driven by stylus and joystick.

The appearance of iOS asked the direction for the development of operating systems for mobile devices.

The iOS user interface is based on the concept of direct manipulation using multitouch gestures. The interface controls consist of sliders, switches and buttons. Developed based on OS X and uses the same set of main Darwin components compatible with the POSIX standard.

IOS has four abstraction layers: layer Core OS, Core Services layer, Media Layer layer, and Cocoa Touch layer.

For the current version of the operating system (iOS 7.0.2), 1.4-2 GB of device flash memory is highlighted for system partition And about 800 MB of free space (varied depending on the model).

As of May 19, 2013, the store app. Store contains more than 900 thousand iOS applications, which all together have been loaded over 50 billion times.

3. Benefits of IOS.

(In comparison with Android - most popular from mobile platforms)

1 Automatic update platform

The order of things with updating the operating system on Android and iOS has developed completely differently. If about the devices running on the basis of Android, it is impossible to say firmly that they are all updated, then I-gadgets this percentage reaches almost all 100%. If you analyze the whole mass of Android devices, some of them only have access to version 4.0, the rest operate in version 2.3, and another quarter received the right to use the latest software. Where does such differentiation come from?

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Figure 6 - ICloud

3 Apple's own services

Discontent towards iTunes, for example, produce only those who do not understand the main purpose of this service, however, like others. Ease of using iCloud has long been proven: synchronization of any data on multiple i devices, tool for creating backup data files, using icloud. For backup, etc.- This is transparent synchronization, Android does not show this for sure. Among Apple's branded software is also iMessage, Facetime, Find My iPhone, etc. All this is in the default IOS devices, you can find something similar in Android, but among third-party software.

3.4 iOS in priority for software developers

App Store App Store is rich in its choice. Android tries to keep up and catches Apple. Nevertheless, most programs, applications, games are primary and written precisely for "apple" devices, so you can always get a release on the App Store. Yes, and applications are better optimized here for various iOS devices.

5 Special features

carefully also about users with disabilities who have problems with vision, hearing, etc. AssistiveTouch, Guide-Access, Inversion of Color, Voiceover, Hearing Support - All this is laid in IOS Initially, Android can find it again within the framework of additional applications.

Listing the main advantages of IOS in front of Android, I want to pay attention to once again: are there any changes to icons or wallpapers on Springboard much more important than security, comfort and stability?

Binding "Iron" to software.

It seems that such a feature is a big minus and at the same time step forward. Applications are created exactly under one device with specific characteristics (iPhone, iPad, including iPod Touch). Thus, users are rarely faced with equipment glitches and problems such as incompatibility.

6 Performance

The operating system has high performance and stability and this is not a fictional opinion, but the opinion of the Company to which he had studied various forums, reviews of friends, services for the similarity of issues and answers.

7 For a long time Work OT rechargeable battery

Unlike operating android systems - IOS managed to implement a high percentage of energy savings. Android users believe that their platform is not fully debugged in terms of using the battery energy. It is known android work discharges the battery very quickly. To manage this process, you need to contact special tricks, which is spent a lot of time. IPhone users know exactly how much their device lives. There are definition problems with the charge of the "apple" products.

8 Proper multitasking

The iOS platform is characterized by a well-realized multitasking. Without any difficulties, you can minimize and deploy the utility. The most important thing is that the rolled programs do not affect the operating system and do not reduce the battery charge. Another indisputable advantage is the fact that each active process is easily closed for several movements convenient operation with wireless tools.

IOS uses access to the network via Wi-Fi. Therefore, a device without third-party help Determines what you need to include. When there is no Wi-Fi near, there is a mobile information transfer technology that turns off in automatic modeif not used.

3.9 Easy to master

IPhone smartphones and iPad tablets perfectly work out the box. The user acquires a certain device, open and start using. Additionally, you can install the necessary applications. All this is done very easily and understandable. Even newcomer will be able to understand actions.

Constantly Apple complains that iPhone or iPad without service iTunes mean zero. Users cannot install an arbitrary application in the selected folder, as access is easy to closed.

1 Activation

The first thing that the newest users of iOS 7 will pay attention - welcome screen. There are no more textures and overloaded interface, but there is a white background, thin fonts, focus on information. In addition to appearance, the initial setup of the device does not differ from the one that was before: offers to read the user agreement, enter the password wireless networkThe inclusion of geolocation services.

2 home screen

It would seem, on the home screen everything is familiar - mesh icons, folders, dock for the most necessary programs. But now everything has become much brighter, minimalist, and instead of a glass shelter at the bottom of the screen, the icons will be arranged on a colorless strip, which blurred background. The principle of operation of folders has changed. Now in the blurred windows you can add an unlimited number of applications. There will be more nine - additional screen will appear inside. Such a feeling seems to be a completely different operating system, albeit with familiar outlines.

3 Search

Search Spotlight, glorified by the second delay before launch, was expelled from the left left screen. Now access to it will have to spend your finger from top to bottom on any screen. Traditional delay ... And it will be at your service.

4.4 Center notifications

In iOS 7, the notification center has lost all functions in addition to displaying notifications. From it, published publications in Twitter and Facebook, but increased the informativeness of the drop-down curtain. Now the center is divided into three tabs: today, everything is missed. On the first collected information from the calendar and the text weather forecast, application notifications are located on the second tab, the third is dedicated to missing events.

Finally, synchronization of notifications appeared. Messages closed by the user on one device will be closed on the others.

5 Command Center

Figure 14 - Command Center

The extended functionality of the notification center, as using popular tweaks from Cydia, did not appear, but the long-awaited switches were decided to highlight a separate curtain. Access to it can be obtained by stroke bottom up. Users can adjust the volume, backlight brightness, drive player, run chamber, flashlight or stopwatch. The switches also appeared wireless connections, Airdrop for transferring files between devices and the orientation lock button.

6 Lock screen

The lock screen lost the usual slider "Slide to Unlock", so now you can spend your finger anywhere in the screen. This hints signature "Unlock" with an arrow that demonstrates only the direction of movement, but not a specific place for the gesture. By analogy with the home-screen stroke up and down, the command center and the notification center will open. To switch modes and viewing news, you no longer need to unlock the device, which is very convenient.

7 Multitasking

In iOS 7, the familiar multitasking panel has changed. She now allows you to see the miniatures of running applications, and you need to close them not long by pressing and cross, but to the finger stroke. Such a principle of work is familiar to users of smartphones running Web OS and Windows Phone.

But changes not only external - the process of operation of applications in the background itself is significantly reworked. Now, depending on the frequency of application use, they can be secretly updated, being inactive so that users receive fresh information at the time of launch. To do this, in the settings, you can choose which applications can be updated in the background, or turn this feature to save battery charging.

8 Settings

Mobile device settings have significantly changed. But not the logic of the section, but the capabilities. Now there is a custom black list that allows you to block unwanted subscribers in the "Phone", "messages" and FaceTime applications. Apple also added new ringtones, alarm clocks, warnings and sound sounds, changed the wallpaper set for the desktop and the lock screen. The settings also have the opportunity to add Flickr and Vimeo accounts.

Virtual Siri Assistant in iOS 7 received two new voices: male and female. Also, Apple programmers taught it more actions than before. In addition to the familiar Funkitsy Siri now can change the settings, find and show twittes, search in Wikipedia and Bing. In addition, the appearance of the dialog box has changed - now it displays the history of appeals to Siri.

Thanks to the updated assistant, interaction with cars has improved. Now Siri can be 95% integrated into the multimedia system and perform various actionswithout being distracted by the road. For example, make calls, open cards and lay the route, include music and change tracks.

10 Game controllers

In iOS 7, advanced support for game controllers will appear. So far, it is too early to judge how it will affect developers and manufacturers of accessories, but you can confidently say that it will not pass unnoticed.

11 ibeacons

Apple engineers still do not want to add to the iPhone NFC moduleBut the programmers decided to implement support for IBEACONS technology. In something, she even exceeds the "near-field". Using a Bluetooth, a smartphone can read information from special beacons and transmit it to applications.

4.12 Extended gesture support

IOS 7 will appear more reasons to use gestures, not by touch. For example, to switch between applications, tabs in the browser, managing emails in the mail client or viewing the sending time.

13 Wi-Fi Hotspot 2.0

Mobile apple devices Now they can automatically switch between mobile Internet and Wi-Fi wireless networks without authentication. If at the operator mobile communications There are also access points installed in the city, smartphones and tablets with a SIM card of this operator in priority will choose faster Wi-Fi. At the same time, users do not even notice how switching occurs.

14 Corporate Functions

Apple's mobile devices are popular in the corporate segment, so that IOS 7 have new features for those who use smartphones and tablets at work. Now there is a VPN setting for individual applications, license management App Store, synchronization of Exchange notes, single identification for enterprises.

15 Airdrop.

16 Standard applications

The application store now has a "popular nearby" tab, which allows you to see what is in demand near the user. Children's applications are now divided into several groups depending on the age rating. The App Store has an automatic update installation, update history and wish list. Apple also increased the limit to download applications from the store by mobile Internet up to 100 MB. Now allows you to perform audio calls.

apple operating performance mobile

Conclusion

The topic of operating systems is very wide and practically inexhaustible, because today there is a sufficiently large number of diverse OS. And analyzing, examining and comparing only some of them, it is impossible to say with great confidence which one is better. Each system has its advantages, disadvantages and individual capabilities, therefore, each user will be able to determine for itself the best OS. Therefore, you should try to use several OS, and then make the final choice.

Time passes quickly and the development of the OS is keeping up with the times. Today, developers have already closely approached the practically complete integration of all devices on this OS. In addition, operating systems are increasingly sharpened under the consumer, and are becoming easier and functional.

Everything is acer that Apple's mobile devices work running iOS. Many know that iOS is a lightweight version of the desktop Mac OS X. Some guess that the Mac OS X is a POSIX-compatible Darwin OS, and those who are seriously interested in IT, know that the Darwin base is the XNU core appeared The light as a result of the merger of the MACH microker and the components of the FreeBSD kernel. However, all these are bare facts that will not tell us anything about how iOS actually works and what is its differences from the desktop counterpart.

Mac OS X.

The operating system installed today on all poppies and (in a modified form) on Iidevice, leads its own story since 1988, which in the world IT is also known in that he has become the year of release of the first beta version of the NextStep operating system. The NextStep itself was the brainchild of the Jobs Steve Developer team, who by that time had already left Apple and founded the NEXT company, which was engaged in the development of computers for educational needs.

At the time of its appearance, NextStep was truly an advanced operating system, which included many technological innovations. The basis of the OS lay the modified Mach microkernel, supplemented by the components of the FreeBSD kernel, including the reference implementation of the network stack. Higher-level NextStep components were written using the Objective-C language and provided a rich object-oriented API application developers. The system was equipped with a developed and very convenient graphical interface (key components of which are preserved in OS X and even iOS) and a powerful development medium, including the visual interface designer known to all modern developers.

After the failure of Next and returning Steve Jobs to Apple in 1997, NextStep was based on the Rhapsody project, which began the development of the Mac OS 9 system. In 2000, the Darwin open project was allocated from Rhapsody, the sources of which were published under the APSL license, And in 2001, OS X 10.0 appeared on its basis, built on it. A few years later, Darwin lay down the operating system for a smartphone prepared for the release of a smartphone, which until 2007, except rumors, was not known almost anything.

XNU and Darwin

Conditionally filling OS X / IOS can be divided into three logical levels: the XNU core, a POSIX compatibility layer (plus various system demons / services) and a NextStep layer that implements the graphic stack, framework and application APIs. Darwin includes the first two layers and distributes freely, but only in the version for OS X. iOS-option ported to Arm architecture and includes some improvements, completely closed and distributed only as firmware for Iidevays (apparently, it is Stripping from porting iOS to other devices).

In essence, Darwin is a "naked" Unix-like OS, which includes a POSIX API, Shell, a set of commands and services that are minimally necessary for system operation in the console mode and run unix software. In this regard, it is similar to the Basic FreeBSD system or the minimum setting of any Arch Linux, which allow you to start the CONSOLE UNIX-software, but do not have a graphic shell or necessary to run serious graphic applications from GNOME or KDE environments.

The Darwin key component is the XNU hybrid core, based, as mentioned above, on the Mach kernel and the components of the FreeBSD kernel, such as processes scheduler, a network stack and a virtual file system (VFS layer). Unlike Mach and FreeBSD, the OS X core uses its own drivers API, named I / O Kit and allows you to write drivers on C ++ using an object-oriented approach that has greatly simplifying development.

iOS uses a slightly modified version of XNU, but due to the fact that the iOS core is closed, to say exactly what Apple has changed, difficult. It is only known that it is collected with other compiler options and a modified memory manager, which takes into account the small volumes of RAM in mobile devices. In all the rest, this is all the same XNU, which can be found as an encrypted cache (kernel + all drivers / modules) in the /System/Library/caches/com.apple.kernelcaches/com.apple.kernelcaches/kernelcache on the device itself.

The level above the kernel in Darwin is located a UNIX / BSD layer, which includes a set of standard Libery Library (LIBC, LIBMATCH, LIBPTHREAD, and so on), as well as tools command line, Shells (bash, tcsh and ksh) and demons, such as Launchd and a standard SSH server. The latter, by the way, can be activated by editing the /System/Library/LaunchDaemons/ssh.plist file. If, of course, jailbreak the device.

On this, the open part of the OS called Darwin ends, and the framework layer begins, which are just forging what we used to count OS X / IOS.

Freymvorki

Darwin implements only the Mac OS / IOS base part, which meets only the low-level functions (drivers, start / stop the system, network management, application isolation, and so on). That part of the system, which is visible to the user and applications, is not included in its composition and is implemented in the so-called framework - sets of libraries and services that are responsible for the formation of a graphic environment and a high-level API for third-party and stock applications.

Info.

As in many other OS, the Mac OS and IOS API is divided into public and private. For third-party applications, an exceptionally public and strongly trimmed API is available, but Jailbreak applications can also use private.

In the standard Delivery of Mac OS and IOS, you can find dozens of different frameworks that are responsible for accessing the most different OS functions - from the address book implementation (AddressBook framework) to the OpenGL library (GLKIT). A set of basic frameworks for the development of graphic applications is combined into the so-called Cocoa API, a kind of metaphraumwork that allows access to the main possibilities of the OS. In iOS, he carries the name Cocoa Touch and differs from the desktop version of the orientation on sensory displays.

Not all framework are available in both OS. Many of them are specific only for iOS. As examples, you can bring ASSETSLIBRARY, which is responsible for working with photos and video, Corebluetooth, allowing you to access the synecuba, or IAD designed to display advertisements in applications. Other frameworks exist only in the desktop version of the system, however, from time to time Apple transfers those or other parts of iOS in Mac OS or back, as, for example, happened to the Coremedia framework, which was initially available only in iOS.

All standard system frameworks can be found in the system directory / System / Library / Frameworks /. Each of them is in its own catalog, called a Bandle (Boundle), which includes resources (images and description of the interface elements), SI chiders describing the API, as well as a dynamically downloadable library (in DylIB format) with a framework.

One of interesting features frameworks - their version. One framework can have several different versions at once, so the application developed for outdated versions of the system will continue to work, even despite the changes made to the new version of the OS. This is how the mechanism for the launch of old iOS applications in iOS 7 and above is implemented. The application developed for iOS 6 will look and work just as if it was launched in iOS 6.

SpringBoard

The level above are applications, system and installed applications. The central place among them occupies, of course, the SpringBoard (only in iOS), implementing the home screen (desktop). It is it that starts the first after the start of the system demons, downloads to the framework memory and the display of the display server (it is also a compositor compositor manager, which is responsible for displaying the image on the screen.

SpringBoard is a link between the operating system and its user, graphic interfaceallowing you to run applications, switch between them, view notifications and manage some system settings (starting with iOS 7). But also this and event handler, such as screen touch or coupling device. Unlike Mac OS X, which uses various applications And the agents demons for the implementation of interface components (Finder, Dashboard, Launchpad and others), in iOS almost all the basic features of the user interface, including the lock screen and the "curtain", are enclosed in one SpringBoard.

Unlike other iOS, iOS applications, located in the / Applications directory, the Springboard on a par with a display server is considered part of the frameworks and is located in the / System / Library / CoreServices / directory. To perform many tasks, it uses plugins that lie in / System / Library / SpringBoardPlugins /. Among other things, there can be found, for example, nowplayingartlockscreen.lockboundle, which is responsible for displaying information about the song played on the lock screen, or incomingcall.serviceboundle, responsible for processing an incoming call.

Starting with iOS 6 SpringBoard is divided into two parts: the desktop itself and the backboard service, responsible for communications with the low-level part of the OS operating with the equipment (HAL level). Backboard is responsible for processing events such as screen touch, keystrokes, obtaining an accelerometer reading, position sensor and light sensor, and also controls the start, suspension and completion of applications.

Springboard and Backboard are so important for iOS, which, if you stop them in some way, the entire system will freeze in place and even the application running at the moment will not respond to the touch of the screen. It distinguishes them from home android screenwhich is just standard Annexwhich can be stopped, replaced or removed from the system at all (in this case, the screen will remain quite working buttons navigation and the status bar with the "curtain").

Applications

At the top of this pyramid are applications. iOS distinguishes embedded (Stock) Highly privileged applications and third party installed from iTunes. And those and others are stored in the system in the form of gangs, in many respects similar to those used for frameworks. The difference lies only that the application's gangs includes a slightly different meta-information, and the dynamic library occupies the executable file in Mach-O format.

Standard directory of storage of stock applications - / Applications /. In iOS, it is absolutely static and varies only during system updates; The user can not get access to it. Third-party applications installed from iTunes, on the contrary, are stored in the user's home directory / VAR / Mobile / Applications / inside subdirectories having a view of 4-2-2-2-4, where two and four are hexadecimal numbers. This is the so-called GUID - a unique identifier that definitely identifies the application in the system and is needed to create an isolated sandbox (Sandbox).

Sandbox

In iOS sandboxes are used to isolate services and applications from the system and from each other. Each third-party application and most systemic work in the sandbox. From a technical point of view, the sandbox is a classic Unix Chroot for the world, enhanced by the TrustedBSD MAC access control system (Sandbox.KEXT kernel module), which cuts off applications not only to files outside the home directory, but also direct access to the gland and many system OS functions.

In general, the application enclosed in the Sandbox is limited in the following features:

• Access to the file system with the exception of your own directory and user's home directory.

• Access to the Media and Library catalogs inside the home directory except Media / DCIM /, Media / Photos /, Library / AddressBook /, Library / Keyboard / and Library / Preferences /.

• Access to information about other processes (the application "considers itself the only one in the system).

• Direct access to the gland (allowed to use only Cocoa API and other frameworks).

• Restriction on use random access memory (controlled by the jatsam mechanism).

All these restrictions correspond to the Sandbox-profile (a set of limiting rules) Container and apply to any third-party application. For the stock applications, in turn, other limitations, softer or rigid ones can be applied. As an example, you can bring mail client (Profile Mobilemail), which generally has the same serious limitations as third-party applications, but can access the entire contents of the Library /. The reverse situation is the Springboard, without restrictions at all.

Inside sandboxes, many system demons work, including, for example, AFC, designed to work with a file system of the device with a PC, but limiting the "scope" only by the user's home directory. All available system Sandbox profiles are located in the / System / Library / Sandbox / Profiles / * directory and are sets of rules written in Scheme. In addition, applications may also include additional sets of rules called Entitlement. In essence, these are all the same profiles, but those who are stitched directly into the binary application file (a kind of self-limitation). You can view these rules, for example, so:
# cat -tv /pplications/mobilesafari.app/mobilesafari | Tail -31 | More
The meaning of the existence of all these constraints is double. The first (and home) task that Sandbox solves is protection against malicious applications. To couple with a thorough check of applications published in iTunes and the ban on the launch of the applications that are not signed by the digital key (read: anyone received from iTunes) This approach gives an excellent result and allows iOS to be on top in the list of the most protected OS viruses.

The second problem is the protection of the system from itself and the user. Bugs can exist both in the stock software from Apple and in the heads of users. Sandbox protects from both. Even if the attacker finds a hole in Safari and tries to exploit it, he will still remain in the sandbox and cannot harm the system. And the user will not be able to "break his favorite phone" and will not write angular reviews to Apple. Fortunately, people You can always make Jailbreak and bypass Sandbox protection (actually, this is the meaning of the jailbreak).

Multitasking

One of the most controversial features of iOS is the implementation of multitasking. It seems to be, but on the other hand, it is not. Compared to traditional desktop OS and notorious Android iOS is not a multitasking operating system in the familiar sense of the word and does not allow applications to work freely in the background. Instead, OS implements the API that the application can use to perform individual tasks while it is in the background.

For the first time, such an API appeared in iOS 4 (before that, background tasks could only perform stock applications) and increased as the operating system develops. Today ( we are talking About iOS 7) The so-called Background API allows you to do the following:

• play audio;

• make VoIP calls;

• receive information about changing location;

• receive push notifications;

• plan a deferred display of notifications;

• request extra time to complete the work after the transition to the background mode;

• exchange data with accessories connected to the device (including Bluetooth);

• receive and send data over the network (starting with iOS 7).

Such work restrictions in the background are needed primarily in order to keep the battery charge and avoid the lags of the interface, so familiar to Android users, where applications can make everything they want. In fact, Apple cares so much about saving the battery, which even implemented a special mechanism for grouping the background actions of applications and their launch to the desired moments, for example, when the smartphone is actively used, connected to a Wi-Fi network or to a charger.

conclusions

It is worth saying that during its development and the subsequent move to the mobile devices of NextStep, not only did not lose all their advantages, but also imagined them. You can listen to the Rosskazni Google employees for a long time, assuring that Android was designed without looking at iOS, but the fact remains: many architectural android solutions Borrowed at IOS. And not because it was so simpler, but thanks to their beauty and efficiency.

Six Stages Download IOS

1. Boot Rom. After turning on the device, the minimalist loader is started, stitched into a constant device memory. His task is to generate initialization of iron and transfer the management of the primary LLB loader. Boot ROM always has factory firmware And it can not be updated.

1. Low Level Bootloader (LLB). Next, the control receives LLB. This is a primary bootloader whose task is to find in the memory of the IBoot device, check its integrity and transfer it to control or switch the device to the recovery mode, if it failed. The LLB code is stored in the device's NAND memory and updated with the installation of the new firmware version. Among other things, it displays the boot logo on the screen.

1. iboot. This is the secondary and main loader of the Iidevice. It includes a file system driver, which receives access to the contents of the NAND memory, finds the kernel and transmits it to control. The IBoot also built into the UART driver, with which you can debug the kernel and the OS, connecting the device to the COM port or the USB port of the computer (using the USB - UART cable).

4 Core. Here everything is as usual. The kernel initializes the equipment, after which the Launchd daemon is controlled.

5 Launchd.. This is the primary process of iOS and Mac OS X, it connects file Systems, Runs demons / services (for example, backupd, configd, locationd), display server, frameworks, and at the last stage of the boot gives the SpringBoard control. In iOS and Mac OS X Launchd, it is used as a replacement of standard / BIN / INIT in UNIX, however its functionality is much wider.

6 SpringBoard. Here is the lock screen!

The first four stages in this circuit form the chain of trust, implemented by reconciling the digital signature of the loaded component. The digital signature has LLB, IBoot and the core, which makes it possible to eliminate the implementation of a chain loader or kernel into a chain, which can be used to download a third-party operating system or jailbreak. The only way to get around this mechanism is to find a hole in one of the booters and use it to bypass check. At one time, several such holes were found in Boot Rom (most famous Limera1N exploit from GeoHot, relevant for iPhone 1-4), and at the beginning of 2014 and in Iboot (Hacker IH8SN0W, the exploit was never published).

Holding the "Home" button when including iPhone, You can make Iboot boot into the so-called recovery mode (Recovery), which allows you to restore iOS firmware or update it using iTunes. However, the automatic OTA update mechanism uses another mode, called DFU (Device Firmware Upgrade), which is activated at an early load stage immediately after Boot ROM and implemented in two components: IBSS and IBEC. In fact, it is an analogues of the LLB and IBOOT, the ultimate goal of which is not to load the OS, but to translate the smartphone to the update mode.