Misplaced Pages

#45954

111-566: BAPP refers to: BAMP refers to: The two acronyms have three major uses: As an operating system , FreeBSD (a BSD descendant) is generally regarded as reliable and robust, and of the operating systems that accurately report uptime remotely, FreeBSD (and other BSD descendants) are the most common free operating system listed in Netcraft's list of the 50 web servers with the longest uptime (uptime on some operating systems such as some versions of Linux cannot be determined remotely), making it

222-410: A native development kit (NDK) for applications or extensions in C or C++, Google App Inventor , a visual environment for novice programmers, and various cross platform mobile web applications frameworks . In January 2014, Google unveiled a framework based on Apache Cordova for porting Chrome HTML 5 web applications to Android, wrapped in a native application shell. Additionally, Firebase

333-428: A system call to perform a block I/O write operation, then the system call might execute the following instructions: While the writing takes place, the operating system will context switch to other processes as normal. When the device finishes writing, the device will interrupt the currently running process by asserting an interrupt request . The device will also place an integer onto the data bus. Upon accepting

444-408: A weather forecast , the user's email inbox, or a news ticker directly on the home screen. A home screen may be made up of several pages, between which the user can swipe back and forth. Third-party apps available on Google Play and other app stores can extensively re- theme the home screen, and even mimic the look of other operating systems, such as Windows Phone . Most manufacturers customize

555-399: A PC and mobile operating system, based on Android, to "compete directly with Microsoft Windows and Google Android". The Chinese Academy of Engineering noted that "more than a dozen" companies were customizing Android following a Chinese ban on the use of Windows 8 on government PCs. Android is developed by Google until the latest changes and updates are ready to be released, at which point

666-694: A choice of non-default runtimes that allow better C++ support. The SDK includes a comprehensive set of development tools, including a debugger , software libraries , a handset emulator based on QEMU , documentation, sample code, and tutorials. Initially, Google's supported integrated development environment (IDE) was Eclipse using the Android Development Tools (ADT) plugin; in December 2014, Google released Android Studio , based on IntelliJ IDEA , as its primary IDE for Android application development. Other development tools are available, including

777-645: A computer even if they are not compatible with the base operating system. A library operating system (libOS) is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with a single application and configuration code to construct a unikernel : a specialized (only the absolute necessary pieces of code are extracted from libraries and bound together ), single address space , machine image that can be deployed to cloud or embedded environments. The operating system code and application code are not executed in separated protection domains (there

888-571: A development of MULTICS for a single user. Because UNIX's source code was available, it became the basis of other, incompatible operating systems, of which the most successful were AT&T 's System V and the University of California 's Berkeley Software Distribution (BSD). To increase compatibility, the IEEE released the POSIX standard for operating system application programming interfaces (APIs), which

999-402: A fluid touch interface, often using the vibration capabilities of the device to provide haptic feedback to the user. Internal hardware, such as accelerometers , gyroscopes and proximity sensors are used by some applications to respond to additional user actions, for example adjusting the screen from portrait to landscape depending on how the device is oriented, or allowing the user to steer

1110-569: A keyboard and mouse. In addition to their availability on commercially available hardware, similar PC hardware-friendly versions of Android are freely available from the Android-x86 project, including customized Android 4.4. Using the Android emulator that is part of the Android SDK , or third-party emulators, Android can also run non-natively on x86 architectures. Chinese companies are building

1221-484: A large legal settlement was paid. In the twenty-first century, Windows continues to be popular on personal computers but has less market share of servers. UNIX operating systems, especially Linux, are the most popular on enterprise systems and servers but are also used on mobile devices and many other computer systems. On mobile devices, Symbian OS was dominant at first, being usurped by BlackBerry OS (introduced 2002) and iOS for iPhones (from 2007). Later on,

SECTION 10

#1733085855046

1332-442: A library with no protection between applications, such as eCos . A hypervisor is an operating system that runs a virtual machine . The virtual machine is unaware that it is an application and operates as if it had its own hardware. Virtual machines can be paused, saved, and resumed, making them useful for operating systems research, development, and debugging. They also enhance portability by enabling applications to be run on

1443-447: A malformed machine instruction . However, the most common error conditions are division by zero and accessing an invalid memory address . Users can send messages to the kernel to modify the behavior of a currently running process. For example, in the command-line environment , pressing the interrupt character (usually Control-C ) might terminate the currently running process. To generate software interrupts for x86 CPUs,

1554-455: A particular application's memory is stored, or even whether or not it has been allocated yet. In modern operating systems, memory which is accessed less frequently can be temporarily stored on a disk or other media to make that space available for use by other programs. This is called swapping , as an area of memory can be used by multiple programs, and what that memory area contains can be swapped or exchanged on demand. Virtual memory provides

1665-564: A press conference in a New York City subway station . Since 2008, Android has seen numerous updates which have incrementally improved the operating system, adding new features and fixing bugs in previous releases. Each major release is named in alphabetical order after a dessert or sugary treat, with the first few Android versions being called " Cupcake ", " Donut ", " Eclair ", and " Froyo ", in that order. During its announcement of Android KitKat in 2013, Google explained that "Since these devices make our lives so sweet, each Android version

1776-503: A program does not interfere with memory already in use by another program. Since programs time share, each program must have independent access to memory. Cooperative memory management, used by many early operating systems, assumes that all programs make voluntary use of the kernel 's memory manager, and do not exceed their allocated memory. This system of memory management is almost never seen any more, since programs often contain bugs which can cause them to exceed their allocated memory. If

1887-408: A program fails, it may cause memory used by one or more other programs to be affected or overwritten. Malicious programs or viruses may purposefully alter another program's memory, or may affect the operation of the operating system itself. With cooperative memory management, it takes only one misbehaved program to crash the system. Memory protection enables the kernel to limit a process' access to

1998-440: A program tries to access memory that is not accessible memory, but nonetheless has been allocated to it, the kernel is interrupted (see § Memory management ) . This kind of interrupt is typically a page fault . When the kernel detects a page fault it generally adjusts the virtual memory range of the program which triggered it, granting it access to the memory requested. This gives the kernel discretionary power over where

2109-632: A range of other electronics, such as game consoles , digital cameras , portable media players , and PCs , each with a specialized user interface. Some well-known derivatives include Android TV for televisions and Wear OS for wearables , both developed by Google. Software packages on Android, which use the APK format, are generally distributed through proprietary application stores like Google Play Store , Amazon Appstore , Samsung Galaxy Store , Huawei AppGallery , Cafe Bazaar , GetJar , and Aptoide , or open source platforms like F-Droid . Android has been

2220-467: A significant amount of CPU time. Direct memory access (DMA) is an architecture feature to allow devices to bypass the CPU and access main memory directly. (Separate from the architecture, a device may perform direct memory access to and from main memory either directly or via a bus.) When a computer user types a key on the keyboard, typically the character appears immediately on the screen. Likewise, when

2331-402: A specific moment in time. Hard real-time systems require exact timing and are common in manufacturing , avionics , military, and other similar uses. With soft real-time systems, the occasional missed event is acceptable; this category often includes audio or multimedia systems, as well as smartphones. In order for hard real-time systems be sufficiently exact in their timing, often they are just

SECTION 20

#1733085855046

2442-469: A split-screen view mode are the 2012 Samsung Galaxy S3 and Note 2 , the former of which received this feature with the premium suite upgrade delivered in TouchWiz with Android 4.1 Jelly Bean. When connecting or disconnecting charging power and when shortly actuating the power button or home button, all while the device is powered off, a visual battery meter whose appearance varies among vendors appears on

2553-425: A top choice among ISPs and hosting providers . A long uptime also indicates that no kernel updates have been deemed necessary, as installing a new kernel requires a reboot and resets the uptime counter of the system. Though the originators of these open source programs did not design them all to work specifically with each other, the combination has become popular because of its low acquisition cost and because of

2664-417: A user moves a mouse , the cursor immediately moves across the screen. Each keystroke and mouse movement generates an interrupt called Interrupt-driven I/O . An interrupt-driven I/O occurs when a process causes an interrupt for every character or word transmitted. Devices such as hard disk drives , solid-state drives , and magnetic tape drives can transfer data at a rate high enough that interrupting

2775-453: A variation of the classic reader/writer problem . The writer receives a pipe from the shell for its output to be sent to the reader's input stream. The command-line syntax is alpha | bravo . alpha will write to the pipe when its computation is ready and then sleep in the wait queue. bravo will then be moved to the ready queue and soon will read from its input stream. The kernel will generate software interrupts to coordinate

2886-430: A vehicle in a racing game by rotating the device, simulating control of a steering wheel . Android devices boot to the home screen , the primary navigation and information "hub" on Android devices, analogous to the desktop found on personal computers. Android home screens are typically made up of app icons and widgets ; app icons launch the associated app, whereas widgets display live, auto-updating content, such as

2997-507: A whole lot like the program has wrapped up". From 2008 to 2013, Hugo Barra served as product spokesperson, representing Android at press conferences and Google I/O , Google's annual developer-focused conference. He left Google in August 2013 to join Chinese phone maker Xiaomi . Less than six months earlier, Google's then- CEO Larry Page announced in a blog post that Andy Rubin had moved from

3108-562: Is remote direct memory access , which enables each CPU to access memory belonging to other CPUs. Multicomputer operating systems often support remote procedure calls where a CPU can call a procedure on another CPU, or distributed shared memory , in which the operating system uses virtualization to generate shared memory that does not physically exist. A distributed system is a group of distinct, networked computers—each of which might have their own operating system and file system. Unlike multicomputers, they may be dispersed anywhere in

3219-484: Is a change away from the currently running process. Similarly, both hardware and software interrupts execute an interrupt service routine . Software interrupts may be normally occurring events. It is expected that a time slice will occur, so the kernel will have to perform a context switch . A computer program may set a timer to go off after a few seconds in case too much data causes an algorithm to take too long. Software interrupts may be error conditions, such as

3330-422: Is difficult to define, but has been called "the layer of software that manages a computer's resources for its users and their applications ". Operating systems include the software that is always running, called a kernel —but can include other software as well. The two other types of programs that can run on a computer are system programs —which are associated with the operating system, but may not be part of

3441-640: Is expanding its low-cost Android One program into the United States, although The Verge notes that the company will presumably not produce the actual devices itself. Google introduced the Pixel and Pixel XL smartphones in October 2016, marketed as being the first phones made by Google, and exclusively featured certain software features, such as the Google Assistant , before wider rollout. The Pixel phones replaced

BAPP - Misplaced Pages Continue

3552-529: Is known as the Android Open Source Project ( AOSP ) and is free and open-source software (FOSS) primarily licensed under the Apache License . However, most devices run the proprietary Android version developed by Google, which ships with additional proprietary closed-source software pre-installed, most notably Google Mobile Services (GMS), which includes core apps such as Google Chrome ,

3663-438: Is low, the system will begin invisibly and automatically closing inactive processes, starting with those that have been inactive for the longest amount of time. Lifehacker reported in 2011 that third-party task-killer applications were doing more harm than good. Some settings for use by developers for debugging and power users are located in a "Developer options" sub menu, such as the ability to highlight updating parts of

3774-426: Is named after a dessert", although a Google spokesperson told CNN in an interview that "It's kind of like an internal team thing, and we prefer to be a little bit—how should I say—a bit inscrutable in the matter, I'll say". In 2010, Google launched its Nexus series of devices, a lineup in which Google partnered with different device manufacturers to produce new devices and introduce new Android versions. The series

3885-443: Is only a single application running, at least conceptually, so there is no need to prevent interference between applications) and OS services are accessed via simple library calls (potentially inlining them based on compiler thresholds), without the usual overhead of context switches , in a way similarly to embedded and real-time OSes. Note that this overhead is not negligible: to the direct cost of mode switching it's necessary to add

3996-499: Is supported by most UNIX systems. MINIX was a stripped-down version of UNIX, developed in 1987 for educational uses, that inspired the commercially available, free software Linux . Since 2008, MINIX is used in controllers of most Intel microchips , while Linux is widespread in data centers and Android smartphones. The invention of large scale integration enabled the production of personal computers (initially called microcomputers ) from around 1980. For around five years,

4107-473: Is that they do not load user-installed software. Consequently, they do not need protection between different applications, enabling simpler designs. Very small operating systems might run in less than 10 kilobytes , and the smallest are for smart cards . Examples include Embedded Linux , QNX , VxWorks , and the extra-small systems RIOT and TinyOS . A real-time operating system is an operating system that guarantees to process events or data by or at

4218-512: Is the latest version and includes improvements specific to foldable phones , tablets, desktop -sized screens , and Chromebooks . Android Inc. was founded in Palo Alto, California , in October 2003 by Andy Rubin , Rich Miner , Nick Sears, and Chris White. Rubin described the Android project as having "tremendous potential in developing smarter mobile devices that are more aware of its owner's location and preferences". The early intentions of

4329-435: Is the part of the operating system that provides protection between different applications and users. This protection is key to improving reliability by keeping errors isolated to one program, as well as security by limiting the power of malicious software and protecting private data, and ensuring that one program cannot monopolize the computer's resources. Most operating systems have two modes of operation: in user mode ,

4440-693: Is the primary application store installed on Android devices that comply with Google's compatibility requirements and license the Google Mobile Services software. Google Play Store allows users to browse, download and update applications published by Google and third-party developers; as of January 2021 , there are more than three million applications available for Android in Play Store. As of July 2013 , 50 billion application installations had been performed. Some carriers offer direct carrier billing for Google Play application purchases, where

4551-470: Is used by default), and adoptable storage. Portable storage is treated as an external storage device. Adoptable storage, introduced on Android 6.0, allows the internal storage of the device to be spanned with the SD card, treating it as an extension of the internal storage. This has the disadvantage of preventing the memory card from being used with another device unless it is reformatted . Android 4.4 introduced

BAPP - Misplaced Pages Continue

4662-638: The Amazon Appstore , GetJar , and SlideMe. F-Droid , another alternative marketplace, seeks to only provide applications that are distributed under free and open source licenses . In October 2020, Google removed several Android applications from Play Store , as they were identified breaching its data collection rules. The firm was informed by International Digital Accountability Council (IDAC) that apps for children like Number Coloring , Princess Salon and Cats & Cosplay , with collective downloads of 20 million, were violating Google's policies. At

4773-536: The Android software development kit (SDK) and, often, Kotlin programming language, which replaced Java as Google's preferred language for Android app development in May 2019, and was originally announced in May 2017. Java is still supported (originally the only option for user-space programs, and is often mixed with Kotlin), as is C++ . Java or other JVM languages, such as Kotlin, may be combined with C /C++, together with

4884-535: The CP/M (Control Program for Microcomputers) was the most popular operating system for microcomputers. Later, IBM bought the DOS (Disk Operating System) from Microsoft . After modifications requested by IBM, the resulting system was called MS-DOS (MicroSoft Disk Operating System) and was widely used on IBM microcomputers. Later versions increased their sophistication, in part by borrowing features from UNIX. Apple 's Macintosh

4995-496: The INT assembly language instruction is available. The syntax is INT X , where X is the offset number (in hexadecimal format) to the interrupt vector table . To generate software interrupts in Unix-like operating systems, the kill(pid,signum) system call will send a signal to another process. pid is the process identifier of the receiving process. signum is

5106-581: The Open Handset Alliance , a consortium of technology companies including Google, device manufacturers such as HTC, Motorola and Samsung, wireless carriers such as Sprint and T-Mobile , and chipset makers such as Qualcomm and Texas Instruments , unveiled itself, with a goal to develop "the first truly open and comprehensive platform for mobile devices". Within a year, the Open Handset Alliance faced two other open source competitors,

5217-556: The Symbian Foundation and the LiMo Foundation , the latter also developing a Linux -based mobile operating system like Google. In September 2007, InformationWeek covered an Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony. On September 23, 2008, Android was introduced by Andy Rubin, Larry Page, Sergey Brin, Cole Brodman, Christopher Schlaeffer and Peter Chou at

5328-729: The Windows 11 announcement event in June 2021, Microsoft showcased the new Windows Subsystem for Android (WSA) to enable support for the Android Open Source Project (AOSP), but it has since been deprecated. It was meant to allow users running Android apps and games in Windows 11 on their Windows desktop. On March 5, 2024, Microsoft announced deprecation of WSA with support ending on March 5, 2025. The storage of Android devices can be expanded using secondary devices such as SD cards . Android recognizes two types of secondary storage: portable storage (which

5439-400: The digital distribution platform Google Play , and the associated Google Play Services development platform. Firebase Cloud Messaging is used for push notifications. While AOSP is free, the "Android" name and logo are trademarks of Google, which imposes standards to restrict the use of Android branding by "uncertified" devices outside their ecosystem. Over 70% of smartphones based on

5550-566: The global operating system market , followed by Windows with 26%. Android has historically been developed by a consortium of developers known as the Open Handset Alliance , but its most widely used version is primarily developed by Google . It was unveiled in November 2007, with the first commercial Android device, the HTC Dream , being launched in September 2008. At its core, the operating system

5661-498: The personal computer market, as of September 2024 , Microsoft Windows holds a dominant market share of around 73%. macOS by Apple Inc. is in second place (15%), Linux is in third place (5%), and ChromeOS is in fourth place (2%). In the mobile sector (including smartphones and tablets ), as of September 2023 , Android's share is 68.92%, followed by Apple's iOS and iPadOS with 30.42%, and other operating systems with .66%. Linux distributions are dominant in

SECTION 50

#1733085855046

5772-523: The source code is made available to the Android Open Source Project (AOSP), an open source initiative led by Google. The first source code release happened as part of the initial release in 2007. All releases are under the Apache License . The AOSP code can be found with minimal modifications on select devices, mainly the former Nexus and current Android One series of devices. However, most original equipment manufacturers (OEMs) customize

5883-420: The transistor in the mid-1950s, mainframes began to be built. These still needed professional operators who manually do what a modern operating system would do, such as scheduling programs to run, but mainframes still had rudimentary operating systems such as Fortran Monitor System (FMS) and IBSYS . In the 1960s, IBM introduced the first series of intercompatible computers ( System/360 ). All of them ran

5994-515: The Android Open Source Project run Google's ecosystem (which is known simply as Android), some with vendor-customized user interfaces and software suites, such as TouchWiz and later One UI by Samsung and HTC Sense . Competing ecosystems and forks of AOSP include Fire OS developed by Amazon , ColorOS by Oppo , OriginOS by Vivo , MagicUI by Honor , and custom ROMs such as LineageOS , as well as Meta Horizon OS for VR headsets . Android's source code has been used to develop variants on

6105-531: The Android division to take on new projects at Google, and that Sundar Pichai would become the new Android lead. Pichai himself would eventually switch positions, becoming the new CEO of Google in August 2015 following the company's restructure into the Alphabet conglomerate, making Hiroshi Lockheimer the new head of Android. On Android 4.4 , KitKat , shared writing access to MicroSD memory cards has been locked for user-installed applications, to which only

6216-514: The Android version and manufacturer. Many early Android OS smartphones were equipped with a dedicated search button for quick access to a web search engine and individual apps' internal search feature. More recent devices typically allow the former through a long press or swipe away from the home button. The dedicated option key, also known as menu key, and its on-screen simulation, is no longer supported since Android version 10. Google recommends mobile application developers to locate menus within

6327-638: The BAPP stack has its origins in the CGI web interfaces that became popular in the early 1990s. This technology allows the user of a web browser to execute a program on the web server, and to thereby receive dynamic as well as static content. Programmers used scripting languages with these programs because of their ability to manipulate text streams easily and efficiently, even when they originate from disparate sources. For this reason system designers often referred to such scripting systems as glue languages . Other variants of

6438-410: The CPU for every byte or word transferred, and having the CPU transfer the byte or word between the device and memory, would require too much CPU time. Data is, instead, transferred between the device and memory independently of the CPU by hardware such as a channel or a direct memory access controller; an interrupt is delivered only when all the data is transferred. If a computer program executes

6549-474: The CPU to re-enter supervisor mode , placing the kernel in charge. This is called a segmentation violation or Seg-V for short, and since it is both difficult to assign a meaningful result to such an operation, and because it is usually a sign of a misbehaving program, the kernel generally resorts to terminating the offending program, and reports the error. Windows versions 3.1 through ME had some level of memory protection, but programs could easily circumvent

6660-634: The Nexus series, with a new generation of Pixel phones launched in October 2017. In May 2019, the operating system became entangled in the trade war between China and the United States involving Huawei , which, like many other tech firms, had become dependent on access to the Android platform. In the summer of 2019, Huawei announced it would create an alternative operating system to Android known as Harmony OS , and has filed for intellectual property rights across major global markets. Under such sanctions Huawei has long-term plans to replace Android in 2022 with

6771-493: The SAF to access any other part of the filesystem. Since Android devices are usually battery-powered, Android is designed to manage processes to keep power consumption at a minimum. When an application is not in use the system suspends its operation so that, while available for immediate use rather than closed, it does not use battery power or CPU resources. Android manages the applications stored in memory automatically: when memory

SECTION 60

#1733085855046

6882-479: The Storage Access Framework (SAF), a set of APIs for accessing files on the device's filesystem. As of Android 11, Android has required apps to conform to a data privacy policy known as scoped storage , under which apps may only automatically have access to certain directories (such as those for pictures, music, and video), and app-specific directories they have created themselves. Apps are required to use

6993-453: The ability to adjust the flashlight brightness. Notifications are "short, timely, and relevant information about your app when it's not in use", and when tapped, users are directed to a screen inside the app relating to the notification. Beginning with Android 4.1 "Jelly Bean" , "expandable notifications" allow the user to tap an icon on the notification in order for it to expand and display more information and possible app actions right from

7104-534: The application program, which then interacts with the user and with hardware devices. However, in some systems an application can request that the operating system execute another application within the same process, either as a subroutine or in a separate thread, e.g., the LINK and ATTACH facilities of OS/360 and successors . An interrupt (also known as an abort , exception , fault , signal , or trap ) provides an efficient way for most operating systems to react to

7215-479: The company in July of that year for at least $ 50 million; this was Google's "best deal ever" according to Google's then-vice president of corporate development, David Lawee , in 2010. Android's key employees, including Rubin, Miner, Sears, and White, joined Google as part of the acquisition. Not much was known about the secretive Android Inc. at the time, with the company having provided few details other than that it

7326-513: The company were to develop an advanced operating system for digital cameras , and this was the basis of its pitch to investors in April 2004. The company then decided that the market for cameras was not large enough for its goals, and five months later it had diverted its efforts and was pitching Android as a handset operating system that would rival Symbian and Microsoft Windows Mobile . Rubin had difficulty attracting investors early on, and Android

7437-453: The computer's memory. Various methods of memory protection exist, including memory segmentation and paging . All methods require some level of hardware support (such as the 80286 MMU), which does not exist in all computers. In both segmentation and paging, certain protected mode registers specify to the CPU what memory address it should allow a running program to access. Attempts to access other addresses trigger an interrupt, which causes

7548-555: The cost of the application is added to the user's monthly bill. As of May 2017 , there are over one billion active users a month for Gmail, Android, Chrome, Google Play and Maps. Due to the open nature of Android, a number of third-party application marketplaces also exist for Android, either to provide a substitute for devices that are not allowed to ship with Google Play Store, provide applications that cannot be offered on Google Play Store due to policy violations, or for other reasons. Examples of these third-party stores have included

7659-511: The dedicated directories with respective package names, located inside Android/data/ , remained writeable. Writing access has been reinstated with Android 5 Lollipop through the backwards-incompatible Google Storage Access Framework interface . In June 2014, Google announced Android One , a set of "hardware reference models" that would "allow [device makers] to easily create high-quality phones at low costs", designed for consumers in developing countries. In September, Google announced

7770-471: The details of how interrupt service routines behave vary from operating system to operating system. However, several interrupt functions are common. The architecture and operating system must: A software interrupt is a message to a process that an event has occurred. This contrasts with a hardware interrupt — which is a message to the central processing unit (CPU) that an event has occurred. Software interrupts are similar to hardware interrupts — there

7881-567: The display, show an overlay with the current status of the touch screen, show touching spots for possible use in screencasting , notify the user of unresponsive background processes with the option to end them ("Show all ANRs", i.e. "App's Not Responding"), prevent a Bluetooth audio client from controlling the system volume ("Disable absolute volume"), and adjust the duration of transition animations or deactivate them completely to speed up navigation. Developer options are initially hidden since Android 4.2 "Jelly Bean", but can be enabled by actuating

7992-422: The environment. Interrupts cause the central processing unit (CPU) to have a control flow change away from the currently running program to an interrupt handler , also known as an interrupt service routine (ISR). An interrupt service routine may cause the central processing unit (CPU) to have a context switch . The details of how a computer processes an interrupt vary from architecture to architecture, and

8103-573: The first set of Android One phones for release in India. However, Recode reported in June 2015 that the project was "a disappointment", citing "reluctant consumers and manufacturing partners" and "misfires from the search company that has never quite cracked hardware". Plans to relaunch Android One surfaced in August 2015, with Africa announced as the next location for the program a week later. A report from The Information in January 2017 stated that Google

8214-410: The hardware checks that the software is only executing legal instructions, whereas the kernel has unrestricted powers and is not subject to these checks. The kernel also manages memory for other processes and controls access to input/output devices. The operating system provides an interface between an application program and the computer hardware, so that an application program can interact with

8325-493: The hardware only by obeying rules and procedures programmed into the operating system. The operating system is also a set of services which simplify development and execution of application programs. Executing an application program typically involves the creation of a process by the operating system kernel , which assigns memory space and other resources, establishes a priority for the process in multi-tasking systems, loads program binary code into memory, and initiates execution of

8436-418: The indirect pollution of important processor structures (like CPU caches , the instruction pipeline , and so on) which affects both user-mode and kernel-mode performance. The first computers in the late 1940s and 1950s were directly programmed either with plugboards or with machine code inputted on media such as punch cards , without programming languages or operating systems. After the introduction of

8547-404: The interrupt request, the operating system will: When the writing process has its time slice expired, the operating system will: With the program counter now reset, the interrupted process will resume its time slice. Among other things, a multiprogramming operating system kernel must be responsible for managing all system memory which is currently in use by the programs. This ensures that

8658-437: The issue. Android's default user interface is mainly based on direct manipulation , using touch inputs that loosely correspond to real-world actions, like swiping, tapping, pinching, and reverse pinching to manipulate on-screen objects, along with a virtual keyboard . Game controllers and full-size physical keyboards are supported via Bluetooth or USB . The response to user input is designed to be immediate and provides

8769-431: The kernel—and applications—all other software. There are three main purposes that an operating system fulfills: With multiprocessors multiple CPUs share memory. A multicomputer or cluster computer has multiple CPUs, each of which has its own memory . Multicomputers were developed because large multiprocessors are difficult to engineer and prohibitively expensive; they are universal in cloud computing because of

8880-559: The look and features of their Android devices to differentiate themselves from their competitors. Along the top of the screen is a status bar, showing information about the device and its connectivity. This status bar can be pulled (swiped) down from to reveal a notification screen where apps display important information or updates, as well as quick access to system controls and toggles such as display brightness, connectivity settings ( WiFi , Bluetooth, cellular data), audio mode, and flashlight . Vendors may implement extended settings such as

8991-400: The memory allocated to a different one. Around the same time, teleprinters began to be used as terminals so multiple users could access the computer simultaneously. The operating system MULTICS was intended to allow hundreds of users to access a large computer. Despite its limited adoption, it can be considered the precursor to cloud computing . The UNIX operating system originated as

9102-481: The mobile communications market continued to build through December 2006. An early prototype had a close resemblance to a BlackBerry phone, with no touchscreen and a physical QWERTY keyboard , but the arrival of 2007's Apple iPhone meant that Android "had to go back to the drawing board". Google later changed its Android specification documents to state that "Touchscreens will be supported", although "the Product

9213-607: The most common screen. Android supports all versions of OpenGL ES and Vulkan (and version 1.1 available for some devices ). Android devices incorporate many optional hardware components, including still or video cameras, GPS , orientation sensors , dedicated gaming controls, accelerometers, gyroscopes, barometers, magnetometers , proximity sensors, pressure sensors , thermometers, and touchscreens . Some hardware components are not required, but became standard in certain classes of devices, such as smartphones, and additional requirements apply if they are present. Some other hardware

9324-475: The most used operating system worldwide on smartphones since 2011 and on tablets since 2013. As of May 2021 , it has over three billion monthly active users , the largest installed base of any operating system in the world, and, as of 2024 , the Google Play Store features 1.7 million apps; a decline from its of peak of over 3 million apps in April 2021. Android 15 , released on October 15, 2024,

9435-408: The need to use it. A general protection fault would be produced, indicating a segmentation violation had occurred; however, the system would often crash anyway. The use of virtual memory addressing (such as paging or segmentation) means that the kernel can choose what memory each program may use at any given time, allowing the operating system to use the same memory locations for multiple tasks. If

9546-513: The new operating system, as Harmony OS was originally designed for internet of things devices, rather than for smartphones and tablets. On August 22, 2019, it was announced that Android "Q" would officially be branded as Android 10, ending the historic practice of naming major versions after desserts. Google stated that these names were not "inclusive" to international users (due either to the aforementioned foods not being internationally known, or being difficult to pronounce in some languages). On

9657-409: The notification. An "All Apps" screen lists all installed applications, with the ability for users to drag an app from the list onto the home screen. The app list may be accessed using a gesture or a button, depending on the Android version. A "Recents" screen, also known as "Overview", lets users switch between recently used apps. The recent list may appear side-by-side or overlapping, depending on

9768-546: The official support. Since 2012, Android devices with Intel processors began to appear, including phones and tablets. While gaining support for 64-bit platforms, Android was first made to run on 64-bit x86 and then on ARM64 . An unofficial experimental port of the operating system to the RISC-V architecture was released in 2021. Requirements for the minimum amount of RAM for devices running Android 7.1 range from in practice 2 GB for best hardware, down to 1 GB for

9879-408: The open-source Android operating system (introduced 2008), with a Linux kernel and a C library ( Bionic ) partially based on BSD code, became most popular. The components of an operating system are designed to ensure that various parts of a computer function cohesively. With the de facto obsoletion of DOS , all user software must interact with the operating system to access hardware. The kernel

9990-420: The operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers . In

10101-526: The operating system's build number in the device information seven times. Hiding developers options again requires deleting user data for the "Settings" app, possibly resetting some other preferences. The main hardware platform for Android is ARM (the ARMv7 and ARMv8-A architectures), with x86 and x86-64 architectures also officially supported in later versions of Android. The unofficial Android-x86 project provided support for x86 architectures ahead of

10212-421: The piping. Signals may be classified into 7 categories. The categories are: Input/output (I/O) devices are slower than the CPU. Therefore, it would slow down the computer if the CPU had to wait for each I/O to finish. Instead, a computer may implement interrupts for I/O completion, avoiding the need for polling or busy waiting. Some computers require an interrupt for each character or word, costing

10323-683: The programmer or the user with the perception that there is a much larger amount of RAM in the computer than is really there. Android (operating system) Android is a mobile operating system based on a modified version of the Linux kernel and other open-source software, designed primarily for touchscreen -based mobile devices such as smartphones and tablets . It is the world's most widely used operating system due to it being used on most smartphones and tablets outside of iPhones and iPads , which use Apple 's iOS and iPadOS , respectively. As of October 2024 , Android accounts for 45% of

10434-520: The same day, Android Police reported that Google had commissioned a statue of a giant number "10" to be installed in the lobby of the developers' new office. Android 10 was released on September 3, 2019, to Google Pixel phones first. In late 2021, some users reported that they were unable to dial emergency services. The problem was caused by a combination of bugs in Android and in the Microsoft Teams app; both companies released updates addressing

10545-418: The same operating system— OS/360 —which consisted of millions of lines of assembly language that had thousands of bugs . The OS/360 also was the first popular operating system to support multiprogramming , such that the CPU could be put to use on one job while another was waiting on input/output (I/O). Holding multiple jobs in memory necessitated memory partitioning and safeguards against one job accessing

10656-419: The screen, allowing the user to quickly assess the charge status of a powered-off without having to boot it up first. Some display the battery percentage. Most Android devices come with preinstalled Google apps including Gmail, Google Maps, Google Chrome, YouTube, Google Play Movies & TV, and others. Applications (" apps "), which extend the functionality of devices (and must be 64-bit ), are written using

10767-619: The server and supercomputing sectors. Other specialized classes of operating systems (special-purpose operating systems), such as embedded and real-time systems, exist for many applications. Security-focused operating systems also exist. Some operating systems have low system requirements (e.g. light-weight Linux distribution ). Others may have higher system requirements. Some operating systems require installation or may come pre-installed with purchased computers ( OEM -installation), whereas others may run directly from media (i.e. live CD ) or flash memory (i.e. USB stick). An operating system

10878-400: The signal number (in mnemonic format) to be sent. (The abrasive name of kill was chosen because early implementations only terminated the process.) In Unix-like operating systems, signals inform processes of the occurrence of asynchronous events. To communicate asynchronously, interrupts are required. One reason a process needs to asynchronously communicate to another process solves

10989-400: The size of the machine needed. The different CPUs often need to send and receive messages to each other; to ensure good performance, the operating systems for these machines need to minimize this copying of packets . Newer systems are often multiqueue —separating groups of users into separate queues —to reduce the need for packet copying and support more concurrent users. Another technique

11100-507: The term include: Operating system An operating system ( OS ) is system software that manages computer hardware and software resources, and provides common services for computer programs . Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time , mass storage , peripherals, and other resources. For hardware functions such as input and output and memory allocation ,

11211-436: The ubiquity of its components (which come bundled with most current BSD distributions particularly as deployed by ISPs). When used in combination they represent a solution stack of technologies that support application servers . Other such stacks include unified application development environments such as Apple 's WebObjects , Java / Jakarta EE , Grails , and Microsoft 's .NET architecture. The scripting component of

11322-495: The user interface. On more recent phones, its place is occupied by a task key used to access the list of recently used apps when actuated. Depending on device, its long press may simulate a menu button press or engage split screen view, the latter of which is the default behaviour since stock Android version 7. Native support for split screen view has been added in stock Android version 7.0 Nougat . The earliest vendor-customized Android-based smartphones known to have featured

11433-473: The world. Middleware , an additional software layer between the operating system and applications, is often used to improve consistency. Although it functions similarly to an operating system, it is not a true operating system. Embedded operating systems are designed to be used in embedded computer systems , whether they are internet of things objects or not connected to a network. Embedded systems include many household appliances. The distinguishing factor

11544-434: Was acquired by Google in 2014 that provides helpful tools for app and web developers. Android has a growing selection of third-party applications, which can be acquired by users by downloading and installing the application's APK (Android application package) file, or by downloading them using an application store program that allows users to install, update, and remove applications from their devices. Google Play Store

11655-490: Was described as having "played a pivotal role in Android's history by introducing new software iterations and hardware standards across the board", and became known for its " bloat-free " software with "timely ... updates". At its developer conference in May 2013, Google announced a special version of the Samsung Galaxy S4 , where, instead of using Samsung's own Android customization, the phone ran "stock Android" and

11766-472: Was designed with the presence of discrete physical buttons as an assumption, therefore a touchscreen cannot completely replace physical buttons". By 2008, both Nokia and BlackBerry announced touch-based smartphones to rival the iPhone 3G , and Android's focus eventually switched to just touchscreens. The first commercially available smartphone running Android was the HTC Dream , also known as T-Mobile G1, announced on September 23, 2008. On November 5, 2007,

11877-432: Was facing eviction from its office space. Steve Perlman , a close friend of Rubin, brought him $ 10,000 in cash in an envelope, and shortly thereafter wired an undisclosed amount as seed funding. Perlman refused a stake in the company, and has stated "I did it because I believed in the thing, and I wanted to help Andy." In 2005, Rubin tried to negotiate deals with Samsung and HTC . Shortly afterwards, Google acquired

11988-586: Was initially required, but those requirements have been relaxed or eliminated altogether. For example, as Android was developed initially as a phone OS, hardware such as microphones were required, while over time the phone function became optional. Android used to require an autofocus camera, which was relaxed to a fixed-focus camera if present at all, since the camera was dropped as a requirement entirely when Android started to be used on set-top boxes . In addition to running on smartphones and tablets, several vendors run Android natively on regular PC hardware with

12099-466: Was making software for mobile phones. At Google, the team led by Rubin developed a mobile device platform powered by the Linux kernel . Google marketed the platform to handset makers and carriers on the promise of providing a flexible, upgradeable system. Google had "lined up a series of hardware components and software partners and signaled to carriers that it was open to various degrees of cooperation". Speculation about Google's intention to enter

12210-683: Was promised to receive new system updates fast. The device would become the start of the Google Play edition program, and was followed by other devices, including the HTC One Google Play edition, and Moto G Google Play edition. In 2015, Ars Technica wrote that "Earlier this week, the last of the Google Play edition Android phones in Google's online storefront were listed as "no longer available for sale" and that "Now they're all gone, and it looks

12321-406: Was the first popular computer to use a graphical user interface (GUI). The GUI proved much more user friendly than the text-only command-line interface earlier operating systems had used. Following the success of Macintosh, MS-DOS was updated with a GUI overlay called Windows . Windows later was rewritten as a stand-alone operating system, borrowing so many features from another ( VAX VMS ) that

#45954