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Red Zone (computing)
In computing, the red zone is a fixed-size area in a function's stack frame below (for a push-down stack) the current stack pointer that is reserved and safe to use. It is most commonly used in leaf functions (functions that don't call other functions) for allocating additional stack memory, without moving the stack pointer, which saves an instruction. Whether a red zone is present depends on the calling convention. x86-64 systems that use the System V AMD64 ABI (including Linux and macOS) use a 128-byte red zone that begins directly under the current value of the stack pointer. The OpenRISC toolchain assumes a 128-byte red zone. Microsoft Windows does not have the concept of a red zone on x86. In fact, the ABI explicitly states that the memory beyond the stack pointer is volatile and may be overwritten by debuggers or interrupt handlers. However, Microsoft Windows has a red zone of 16 bytes on IA-64, 8 bytes on AArch32, and 16 bytes on AArch64. The red zone is safe from modificatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, engineering, mathematical, technological and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology and software engineering. The term "computing" is also synonymous with counting and calculating. In earlier times, it was used in reference to the action performed by mechanical computing machines, and before that, to human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. Computing is intimately tied to the representation of numbers, though mathematical conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stack Frame
In computer science, a call stack is a stack data structure that stores information about the active subroutines of a computer program. This kind of stack is also known as an execution stack, program stack, control stack, run-time stack, or machine stack, and is often shortened to just "the stack". Although maintenance of the call stack is important for the proper functioning of most software, the details are normally hidden and automatic in high-level programming languages. Many computer instruction sets provide special instructions for manipulating stacks. A call stack is used for several related purposes, but the main reason for having one is to keep track of the point to which each active subroutine should return control when it finishes executing. An active subroutine is one that has been called, but is yet to complete execution, after which control should be handed back to the point of call. Such activations of subroutines may be nested to any level (recursive as a special ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stack Pointer
In computer science, a call stack is a stack data structure that stores information about the active subroutines of a computer program. This kind of stack is also known as an execution stack, program stack, control stack, run-time stack, or machine stack, and is often shortened to just "the stack". Although maintenance of the call stack is important for the proper functioning of most software, the details are normally hidden and automatic in high-level programming languages. Many computer instruction sets provide special instructions for manipulating stacks. A call stack is used for several related purposes, but the main reason for having one is to keep track of the point to which each active subroutine should return control when it finishes executing. An active subroutine is one that has been called, but is yet to complete execution, after which control should be handed back to the point of call. Such activations of subroutines may be nested to any level (recursive as a special ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X86 Calling Conventions
This article describes the calling conventions used when programming x86 architecture microprocessors. Calling conventions describe the interface of called code: *The order in which atomic (scalar) parameters, or individual parts of a complex parameter, are allocated *How parameters are passed (pushed on the stack, placed in registers, or a mix of both) *Which registers the called function must preserve for the caller (also known as: callee-saved registers or non-volatile registers) *How the task of preparing the stack for, and restoring after, a function call is divided between the caller and the callee This is intimately related with the assignment of sizes and formats to programming-language types. Another closely related topic is name mangling, which determines how symbol names in the code are mapped to symbol names used by the linker. Calling conventions, type representations, and name mangling are all part of what is known as an application binary interface (ABI). There ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X86-64
x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit version of the x86 instruction set, first released in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging mode. With 64-bit mode and the new paging mode, it supports vastly larger amounts of virtual memory and physical memory than was possible on its 32-bit predecessors, allowing programs to store larger amounts of data in memory. x86-64 also expands general-purpose registers to 64-bit, and expands the number of them from 8 (some of which had limited or fixed functionality, e.g. for stack management) to 16 (fully general), and provides numerous other enhancements. Floating-point arithmetic is supported via mandatory SSE2-like instructions, and x87/ MMX style registers are generally not used (but still available even in 64-bit mode); instead, a set of 16 vector registers, 128 bits each, is used. (Each register can store one or two double-preci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name "GNU/Linux" to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian, Fedora Linux, and Ubuntu, the latter of which itself consists of many different distributions and modifications, including Lubuntu and Xubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions intended for ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacOS
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and laptop computers it is the second most widely used desktop OS, after Microsoft Windows and ahead of ChromeOS. macOS succeeded the classic Mac OS, a Mac operating system with nine releases from 1984 to 1999. During this time, Apple cofounder Steve Jobs had left Apple and started another company, NeXT, developing the NeXTSTEP platform that would later be acquired by Apple to form the basis of macOS. The first desktop version, Mac OS X 10.0, was released in March 2001, with its first update, 10.1, arriving later that year. All releases from Mac OS X 10.5 Leopard and after are UNIX 03 certified, with an exception for OS X 10.7 Lion. Apple's other operating systems (iOS, iPadOS, watchOS, tvOS, audioOS) are derivatives of macOS. A promi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenRISC
OpenRISC is a project to develop a series of open-source hardware based central processing units (CPUs) on established reduced instruction set computer (RISC) principles. It includes an instruction set architecture (ISA) using an open-source license. It is the original flagship project of the OpenCores community. The first (and only) architectural description is for the OpenRISC 1000 ("OR1k"), describing a family of 32-bit and 64-bit processors with optional floating-point arithmetic and vector processing support. The OpenRISC 1200 implementation of this specification was designed by Damjan Lampret in 2000, written in the Verilog hardware description language (HDL). The later mor1kx implementation, which has some advantages compared to the OR 1200, was designed by Julius Baxter and is also written in Verilog. Additionally software simulators exist, which implement the OR1k specification. The hardware design was released under the GNU Lesser General Public License (LGPL), while t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toolchain
In software, a toolchain is a set of programming tools that is used to perform a complex software development task or to create a software product, which is typically another computer program or a set of related programs. In general, the tools forming a toolchain are executed consecutively so the output or resulting environment state of each tool becomes the input or starting environment for the next one, but the term is also used when referring to a set of related tools that are not necessarily executed consecutively. A simple software development toolchain may consist of a compiler and linker (which transform the source code into an executable program), libraries (which provide interfaces to the operating system), and a debugger (which is used to test and debug created programs). A complex software product such as a video game needs tools for preparing sound effects, music, textures, 3-dimensional models and animations, together with additional tools for combining these resourc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IA-64
IA-64 (Intel Itanium architecture) is the instruction set architecture (ISA) of the Itanium family of 64-bit Intel microprocessors. The basic ISA specification originated at Hewlett-Packard (HP), and was subsequently implemented by Intel in collaboration with HP. The first Itanium processor, codenamed ''Merced'', was released in 2001. The Itanium architecture is based on explicit instruction-level parallelism, in which the compiler decides which instructions to execute in parallel. This contrasts with superscalar architectures, which depend on the processor to manage instruction dependencies at runtime. In all Itanium models, up to and including '' Tukwila'', cores execute up to six instructions per clock cycle. In 2008, Itanium was the fourth-most deployed microprocessor architecture for enterprise-class systems, behind x86-64, Power ISA, and SPARC. History Development: 1989–2000 In 1989, HP began to become concerned that reduced instruction set computing (RISC) archite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AArch32
ARM (stylised in lowercase as arm, formerly an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a family of reduced instruction set computer (RISC) instruction set architectures for computer processors, configured for various environments. Arm Ltd. develops the architectures and licenses them to other companies, who design their own products that implement one or more of those architectures, including system on a chip (SoC) and system on module (SOM) designs, that incorporate different components such as memory, interfaces, and radios. It also designs cores that implement these instruction set architectures and licenses these designs to many companies that incorporate those core designs into their own products. There have been several generations of the ARM design. The original ARM1 used a 32-bit internal structure but had a 26-bit address space that limited it to 64 MB of main memory. This limitation was removed in the ARMv3 series, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AArch64
AArch64 or ARM64 is the 64-bit extension of the ARM architecture family. It was first introduced with the Armv8-A architecture. Arm releases a new extension every year. ARMv8.x and ARMv9.x extensions and features Announced in October 2011, ARMv8-A represents a fundamental change to the ARM architecture. It adds an optional 64-bit architecture, named "AArch64", and the associated new "A64" instruction set. AArch64 provides user-space compatibility with the existing 32-bit architecture ("AArch32" / ARMv7-A), and instruction set ("A32"). The 16-32bit Thumb instruction set is referred to as "T32" and has no 64-bit counterpart. ARMv8-A allows 32-bit applications to be executed in a 64-bit OS, and a 32-bit OS to be under the control of a 64-bit hypervisor. ARM announced their Cortex-A53 and Cortex-A57 cores on 30 October 2012. Apple was the first to release an ARMv8-A compatible core (Cyclone) in a consumer product (iPhone 5S). AppliedMicro, using an FPGA, was the first to demo ARMv8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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