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x86-64, the 64-bit version of the x86 architecture, almost entirely removes segmentation in favor of the flat memory model used by almost all operating systems for the 386 or newer processors. In long mode, all segment offsets are ignored, except for the FS and GS segments; linear addresses are 64-bit rather than 32-bit, with the lowest 48 bits ...
Most CPUs are byte-addressable, where each unique memory address refers to an 8-bit byte. Most CPUs can access individual bytes from each memory address, but they generally cannot access larger units (16 bits, 32 bits, 64 bits and so on) without these units being "aligned" to a specific boundary (the x86 platform being a notable exception).
Protected mode may only be entered after the system software sets up one descriptor table and enables the Protection Enable (PE) bit in the control register 0 (CR0). [5] Protected mode was first added to the x86 architecture in 1982, [6] with the release of Intel's 80286 (286) processor, and later extended with the release of the 80386 (386) in ...
A 2010 simulation study showed that, for a web browser, only a small fraction of memory errors caused data corruption, although, as many memory errors are intermittent and correlated, the effects of memory errors were greater than would be expected for independent soft errors. [8]
Faulty heap memory management: Memory leaks and freeing non-heap or un-allocated memory are the most frequent errors caused by faulty heap memory management. Many memory debuggers such as Purify, Valgrind, Insure++, Parasoft C/C++test, AddressSanitizer are available to detect memory corruption errors.
In operating systems, memory management is the function responsible for managing the computer's primary memory. [1]: 105–208 The memory management function keeps track of the status of each memory location, either allocated or free. It determines how memory is allocated among competing processes, deciding which gets memory, when they receive ...
The PCI hole or PCI memory hole is a limitation of 32-bit hardware and 32-bit operating systems that causes a computer to appear to have less memory available than is physically installed. [1] This memory addressing limitation and the later workarounds necessary to overcome it are functionally similar to the memory limits of the early 8088 IBM ...
That selector consists of a 2-bit Requested Privilege Level (RPL), a 1-bit Table Indicator (TI), and a 13-bit index. When attempting address translation of a given logical address, the processor reads the 64-bit segment descriptor structure from either the Global Descriptor Table when TI=0 or the Local Descriptor Table when TI=1. It then ...