|
Mach-O
Mach-O (Mach object) file format, is a file format for executables, object code, shared libraries, dynamically loaded code, and core dumps. It was developed to replace the a.out format. Mach-O is used by some systems based on the Mach kernel. NeXTSTEP, macOS, and iOS are examples of systems that use this format for native executables, libraries and object code. Mach-O file layout Each Mach-O file is made up of one Mach-O header, followed by a series of load commands, followed by one or more segments, each of which contains between 0 and 255 sections. Mach-O uses the REL relocation format to handle references to symbols. When looking up symbols Mach-O uses a two-level namespace that encodes each symbol into an 'object/symbol name' pair that is then linearly searched for, first by the object and then the symbol name. The basic structure—a list of variable-length "load commands" that reference pages of data elsewhere in the file—was also used in the executable file for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Core Dump
In computing, a core dump, memory dump, crash dump, storage dump, system dump, or ABEND dump consists of the recorded state of the working Computer storage, memory of a computer program at a specific time, generally when the program has crash (computing), crashed or otherwise terminated abnormally. In practice, other key pieces of Context switch, program state are usually dumped at the same time, including the processor registers, which may include the program counter and stack pointer, memory management information, and other processor and operating system flags and information. A snapshot dump (or snap dump) is a memory dump requested by the computer operator or by the running program, after which the program is able to continue. Core dumps are often used to assist in diagnosing and debugging errors in computer programs. On many operating systems, a fatal exception in a program automatically triggers a core dump. By extension, the phrase "to dump core" has come to mean in many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relocation (computer Science)
In software development, relocation is the process of assigning load addresses for position-dependent code and data of a program and adjusting the code and data to reflect the assigned addresses. A linker usually performs relocation in conjunction with ''symbol resolution'', the process of searching files and libraries to replace symbolic references or names of libraries with actual usable addresses in memory before running a program. Relocation is typically done by the linker at link time, but it can also be done at load time by a relocating loader, or at run time by the running program itself. Segmentation Object files are typically segmented into various memory segment or section types. Example segment types include code segment (.text), initialized data segment (.data), uninitialized data segment (.bss), or others as established by the programmer, such as common segments, or named static segments. Relocation table The relocation table is a list of address ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illegal Instruction
An illegal opcode, also called an unimplemented operation, unintended opcode or undocumented instruction, is an instruction to a CPU that is not mentioned in any official documentation released by the CPU's designer or manufacturer, which nevertheless has an effect. Illegal opcodes were common on older CPUs designed during the 1970s, such as the MOS Technology 6502, Intel 8086, and the Zilog Z80. Unlike modern processors, those older processors have a very limited transistor budget, and thus to save space their designers often omitted circuitry to detect invalid opcodes and generate a trap to an error handler. The operation of many of these opcodes happens as a side effect of the wiring of transistors in the CPU, and usually combines functions of the CPU that were not intended to be combined. On old and modern processors, there are also instructions intentionally included in the processor by the manufacturer, but that are not documented in any official specification. Overview ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM RS/6000
The RISC System/6000 is a family of RISC-based (Reduced Instruction Set Computer-based) Unix servers, workstations and supercomputers made by IBM in the 1990s. The RS/6000 family replaced the IBM RT PC computer platform in February 1990 and is the first computer line to see the use of IBM's POWER and PowerPC based microprocessors. In October 2000, the RS/6000 brand was retired for POWER-based servers and replaced by the eServer pSeries. Workstations continued under the RS/6000 brand until 2002, when new POWER/-based workstations were released under the IntelliStation POWER/ brand. The RS/6000 floating-point execution unit (FPU) enabled major improvements in the speed and accuracy of floating-point operations. The key feature of the FPU was introducing the MAF (multiply-add fused) operation, which has since become standard in most modern processors. History The first RS/6000 models used the IBM Standard Micro Channel (SMC) bus; later models used PCI. Some later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DEC Alpha
Alpha (original name Alpha AXP) is a 64-bit reduced instruction set computer (RISC) instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC). Alpha was designed to replace 32-bit VAX complex instruction set computers (CISC) and to be a highly competitive RISC processor for Unix workstations and similar markets. Alpha was implemented in a series of microprocessors originally developed and fabricated by DEC. These microprocessors were most prominently used in a variety of DEC workstations and servers, which eventually formed the basis for almost all of their mid-to-upper-scale lineup. Several third-party vendors also produced Alpha systems, including PC form factor motherboards. Operating systems that support Alpha included OpenVMS (formerly named OpenVMS AXP), Tru64 UNIX (formerly named DEC OSF/1 AXP and Digital UNIX), Windows NT (discontinued after NT 4.0; and prerelease Windows 2000 RC2), Linux (Debian, SUSE, Gentoo and Red Hat), BSD UNIX (NetBS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel I860
The Intel i860 (also known as 80860) is a RISC microprocessor design introduced by Intel in 1989. It is one of Intel's first attempts at an entirely new, high-end instruction set architecture since the failed Intel iAPX 432 from the beginning of the 1980s. It was the world's first million-transistor chip. It was released with considerable fanfare, slightly obscuring the earlier Intel i960, which was successful in some niches of embedded systems. The i860 never achieved commercial success and the project was terminated in the mid-1990s. Implementations The first implementation of the i860 architecture is the i860 XR microprocessor (code-named N10), which ran at 25, 33, or 40 MHz. The second-generation i860 XP microprocessor (code named N11) added 4 Mbyte pages, larger on-chip caches, second level cache support, faster buses, and hardware support for bus snooping to provide cache coherence in multiprocessor systems. A process shrink for the XP from 1 μm to 0.8 μm usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola 88000
The 88000 (m88k for short) is a RISC instruction set architecture developed by Motorola during the 1980s. The MC88100 arrived on the market in 1988, some two years after the competing SPARC and MIPS. Due to the late start and extensive delays releasing the second-generation MC88110, the m88k achieved very limited success outside of the MVME platform and embedded controller environments. When Motorola joined the AIM alliance in 1991 to develop the PowerPC, further development of the 88000 ended. History Background Motorola entered the 1980s in a position of strength; the company's recently-introduced Motorola 68000 easily outperformed any other microprocessor on the market, and its 32-bit architecture was naturally suited to the emerging workstation market. Intel was not moving aggressively into the 32-bit space, and the companies that did, notably National Semiconductor, botched their releases and left Motorola in control of everything that was not Intel. At the time, Intel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARM Architecture Family
ARM (stylised in lowercase as arm, formerly an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a family of RISC instruction set architectures (ISAs) for computer processors. Arm Holdings develops the ISAs and licenses them to other companies, who build the physical devices that use the instruction set. It also designs and licenses cores that implement these ISAs. Due to their low costs, low power consumption, and low heat generation, ARM processors are useful for light, portable, battery-powered devices, including smartphones, laptops, and tablet computers, as well as embedded systems. However, ARM processors are also used for desktops and servers, including Fugaku, the world's fastest supercomputer from 2020 to 2022. With over 230 billion ARM chips produced, , ARM is the most widely used family of instruction set architectures. There have been several generations of the ARM design. The original ARM1 used a 32-bit internal structure but h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIPS Architecture
MIPS (Microprocessor without Interlocked Pipelined Stages) is a family of reduced instruction set computer (RISC) instruction set architectures (ISA)Price, Charles (September 1995). ''MIPS IV Instruction Set'' (Revision 3.2), MIPS Technologies, Inc. developed by MIPS Computer Systems, now MIPS Technologies, based in the United States. There are multiple versions of MIPS, including MIPS I, II, III, IV, and V, as well as five releases of MIPS32/64 (for 32- and 64-bit implementations, respectively). The early MIPS architectures were 32-bit; 64-bit versions were developed later. As of April 2017, the current version of MIPS is MIPS32/64 Release 6. MIPS32/64 primarily differs from MIPS I–V by defining the privileged kernel mode System Control Coprocessor in addition to the user mode architecture. The MIPS architecture has several optional extensions: MIPS-3D, a simple set of floating-point SIMD instructions dedicated to 3D computer graphics; MDMX (MaDMaX), a more extensive i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola 68000 Series
The Motorola 68000 series (also known as 680x0, m68000, m68k, or 68k) is a family of 32-bit computing, 32-bit complex instruction set computer (CISC) microprocessors. During the 1980s and early 1990s, they were popular in personal computers and workstations and were the primary competitors of Intel's x86 microprocessors. They were best known as the processors used in the early Apple Mac (computer), Macintosh, the Sharp X68000, the Commodore Amiga, the Sinclair QL, the Atari ST and Atari Falcon, Falcon, the Atari Jaguar, the Sega Genesis (Mega Drive) and Sega CD, the Philips CD-i, the CP System, Capcom System I (Arcade), the AT&T UNIX PC, the Tandy TRS-80 Model II#Model 16B and Tandy 6000, Model 16/16B/6000, the Sun Microsystems Sun-1, Sun-2 and Sun-3, the NeXT Computer, NeXTcube, NeXTstation, and NeXTcube Turbo, early Silicon Graphics IRIS workstations, the Aesthedes, computers from MASSCOMP, the Texas Instruments TI-89/TI-92 calculators, the Palm Pilot (all models running Palm OS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NS32000
The NS32000, sometimes known as the 32k, is a series of microprocessors produced by National Semiconductor. Design work began around 1980 and it was announced at the International Solid-State Circuits Conference in April 1981. The first member of the family came to market in 1982, briefly known as the 16032 before being renamed as the 32016. It was the first general-purpose microprocessor on the market that used 32-bit data internally: the Motorola 68000 had 32-bit registers and instructions to perform 32-bit arithmetic, but used a 16-bit ALU for arithmetic operations on data, and thus took twice as long as the 32016 to perform those arithmetic operations. However, the 32016 contained many bugs and often could not be run at its rated speed. These problems, and the presence of the otherwise similar 68000 which had been available since 1980, led to little use in the market despite considerable early interest. Several improved versions followed, including 1985's 32032 which was ess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
