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Low-Level Bootloader
iBoot is the stage 2 bootloader for iPhones, iPads, Apple silicon-based Macs, and the T2 chip in Intel-based Macs with such a chip. Compared with its predecessor, iBoot improves authentication performed in the boot chain. For Intel-based Macs with a T2 chip, the boot process starts by running code on the T2 chip from the boot ROM. That boot ROM loads and runs iBoot onto the T2 chip; iBoot loads the bridgeOS operating system onto the T2 chip and starts it; bridgeOS loads the UEFI firmware; UEFI firmware starts the main Intel processor and completes the Power-On Self Test process. The UEFI firmware loads boot.efi, which loads and starts the macOS kernel. For iPhones, iPads and Apple silicon-based Macs, the boot process starts by running the device's boot ROM. On iPhones and iPads with A9 or earlier A-series processors, the boot ROM loads the (LLB), which is the stage 1 bootloader and loads iBoot; on Macs and devices with A10 or later processors, the boot ROM loads iBoot. If al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Inc
Apple Inc. is an American multinational corporation and technology company headquartered in Cupertino, California, in Silicon Valley. It is best known for its consumer electronics, software, and services. Founded in 1976 as Apple Computer Company by Steve Jobs, Steve Wozniak and Ronald Wayne, the company was incorporated by Jobs and Wozniak as Apple Computer, Inc. the following year. It was renamed Apple Inc. in 2007 as the company had expanded its focus from computers to consumer electronics. Apple is the largest technology company by revenue, with billion in the 2024 fiscal year. The company was founded to produce and market Wozniak's Apple I personal computer. Its second computer, the Apple II, became a best seller as one of the first mass-produced microcomputers. Apple introduced the Lisa in 1983 and the Macintosh in 1984, as some of the first computers to use a graphical user interface and a mouse. By 1985, internal company problems led to Jobs leavin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple A9
The Apple A9 is a 64-bit ARM-based system-on-chip (SoC) designed by Apple Inc., part of the Apple silicon series. Manufactured for Apple by both TSMC and Samsung, it first appeared in the iPhone 6s and 6s Plus which were introduced on September 9, 2015. Apple states that it has 70% more CPU performance and 90% more graphics performance compared to its predecessor, the Apple A8. On September 12, 2018, the iPhone 6s and iPhone 6s Plus along with the first-generation iPhone SE was discontinued, ending production of A9 chips. The latest software updates for the iPhone 6s & 6s Plus including the iPhone SE (1st generation) variants systems using this chip are iOS 15.8.4, released around August, 2024, as they were discontinued with the release of iOS 16 in 2022, and for the iPad (5th generation) using this chip was iPadOS 16.7.10, also released on September 3, 2024, as it was discontinued with the release of iPadOS 17 in 2023. Design The A9 features an Apple-designed 64-bit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dangling Pointer
Dangling pointers and wild pointers in computer programming are pointers that do not point to a valid object of the appropriate type. These are special cases of memory safety violations. More generally, dangling references and wild references are references that do not resolve to a valid destination. Dangling pointers arise during object destruction, when an object that is pointed to by a given pointer is deleted or deallocated, without modifying the value of that said pointer, so that the pointer still points to the memory location of the deallocated memory. The system may reallocate the previously freed memory, and if the program then dereferences the (now) dangling pointer, '' unpredictable behavior may result'', as the memory may now contain completely different data. If the program writes to memory referenced by a dangling pointer, a silent corruption of unrelated data may result, leading to subtle bugs that can be extremely difficult to find. If the memory has been real ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arbitrary Code Execution
In computer security, arbitrary code execution (ACE) is an attacker's ability to run any commands or code of the attacker's choice on a target machine or in a target process. An arbitrary code execution vulnerability is a security flaw in software or hardware allowing arbitrary code execution. A program that is designed to exploit such a vulnerability is called an arbitrary code execution exploit. The ability to trigger arbitrary code execution over a network (especially via a wide-area network such as the Internet) is often referred to as remote code execution (RCE or RCX). Arbitrary code execution signifies that if someone sends a specially designed set of data to a computer, they can make it do whatever they want. Even though this particular weakness may not cause actual problems in the real world, researchers have discussed whether it suggests a natural tendency for computers to have vulnerabilities that allow unauthorized code execution. Vulnerability types There are a n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heap Overflow
A heap overflow, heap overrun, or heap smashing is a type of buffer overflow that occurs in the heap data area. Heap overflows are exploitable in a different manner to that of stack-based overflows. Memory on the heap is dynamically allocated at runtime and typically contains program data. Exploitation is performed by corrupting this data in specific ways to cause the application to overwrite internal structures such as linked list pointers. The canonical heap overflow technique overwrites dynamic memory allocation linkage (such as malloc metadata) and uses the resulting pointer exchange to overwrite a program function pointer. For example, on older versions of Linux, two buffers allocated next to each other on the heap could result in the first buffer overwriting the second buffer's metadata. By setting the in-use bit to zero of the second buffer and setting the length to a small negative value which allows null bytes to be copied, when the program calls free() on the first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IOS 14
iOS 14 is the fourteenth major release of the iOS mobile operating system developed by Apple for the iPhone and iPod touch lines. Announced at the company's Worldwide Developers Conference on June 22, 2020 as the successor to iOS 13, it was released to the public on September 16, 2020. It was succeeded by iOS 15 on September 20, 2021. System features App Clips App Clips are a new feature expanding on the functionality of the App Store. Intended as a dynamic feature rather than a permanently installed app, App Clips are extremely pared-back with very few OS permissions. At the time of the announcement, only the use of Apple Pay and Sign in with Apple were shown. App Clips may be discovered in person via NFC tags (iPhone 7 or newer) or QR codes with App Clips branding. They may also be shared via Messages, or placed on websites or Maps. CarPlay CarPlay was updated to allow users to set a built-in wallpaper. Route management in Apple Maps was extended with features alerting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Safety
Memory safety is the state of being protected from various software bugs and security vulnerabilities when dealing with memory access, such as buffer overflows and dangling pointers. For example, Java is said to be memory-safe because its runtime error detection checks array bounds and pointer dereferences. In contrast, C and C++ allow arbitrary pointer arithmetic with pointers implemented as direct memory addresses with no provision for bounds checking, and thus are potentially memory-unsafe. History Memory errors were first considered in the context of resource management (computing) and time-sharing systems, in an effort to avoid problems such as fork bombs. Developments were mostly theoretical until the Morris worm, which exploited a buffer overflow in fingerd. The field of computer security developed quickly thereafter, escalating with multitudes of new attacks such as the return-to-libc attack and defense techniques such as the non-executable stack and ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toolchain
A toolchain is a set of software development tools used to build and otherwise develop software. Often, the tools are executed sequentially and form a pipeline such that the output of one tool is the input for the next. Sometimes the term is used for a set of related tools that are not necessarily executed sequentially. A relatively common and simple toolchain consists of the tools to build for a particular operating system (OS) and CPU architecture; consisting of a compiler, a linker, and a debugger. With a cross-compiler, a toolchain can support cross-platform development. For building more complex software systems, many other tools may be in the toolchain. For example, for a video game, the toolchain may include tools for preparing sound effects, music, textures, 3-dimensional models and animation Animation is a filmmaking technique whereby still images are manipulated to create moving images. In traditional animation, images are drawn or painted by hand on tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced'' '' – like the letter c'') is a general-purpose programming language. It was created in the 1970s by Dennis Ritchie and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted Central processing unit, CPUs. It has found lasting use in operating systems code (especially in Kernel (operating system), kernels), device drivers, and protocol stacks, but its use in application software has been decreasing. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the most widely used programming langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GitHub
GitHub () is a Proprietary software, proprietary developer platform that allows developers to create, store, manage, and share their code. It uses Git to provide distributed version control and GitHub itself provides access control, bug tracking system, bug tracking, software feature requests, task management, continuous integration, and wikis for every project. Headquartered in California, GitHub, Inc. has been a subsidiary of Microsoft since 2018. It is commonly used to host open source software development projects. GitHub reported having over 100 million developers and more than 420 million Repository (version control), repositories, including at least 28 million public repositories. It is the world's largest source code host Over five billion developer contributions were made to more than 500 million open source projects in 2024. About Founding The development of the GitHub platform began on October 19, 2005. The site was launched in April 2008 by Tom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple M1
Apple M1 is a series of ARM-based system-on-a-chip (SoC) designed by Apple Inc., launched 2020 to 2022. It is part of the Apple silicon series, as a central processing unit (CPU) and graphics processing unit (GPU) for its Mac desktops and notebooks, and the iPad Pro and iPad Air tablets. The M1 chip initiated Apple's third change to the instruction set architecture used by Macintosh computers, switching from Intel to Apple silicon fourteen years after they were switched from PowerPC to Intel, and twenty-six years after the transition from the original Motorola 68000 series to PowerPC. At the time of its introduction in 2020, Apple said that the M1 had "the world's fastest CPU core in low power silicon" and the world's best CPU performance per watt. Its successor, Apple M2, was announced on June 6, 2022, at Worldwide Developers Conference (WWDC). The original M1 chip was introduced in November 2020, and was followed by the professional-focused M1 Pro and M1 Max chips in Oc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
