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Executable-space Protection
In computer security, executable-space protection marks memory regions as non-executable, such that an attempt to execute machine code in these regions will cause an exception. It relies on hardware features such as the NX bit (no-execute bit), or on software emulation when hardware support is unavailable. Software emulation often introduces a performance cost, or overhead (extra processing time or resources), while hardware-based NX bit implementations have no measurable performance impact. The Burroughs large systems, starting with the Burroughs 5000 introduced in 1961, implemented executable-space protection using a tagged architecture. All accesses to code and data took place through descriptors, which had memory tags preventing them from being modified; descriptors for code did not allow the code to be modified, and descriptors for data did not allow the data ta be executed as code. Today, operating systems use executable-space protection to mark writable memory areas, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Security
Computer security (also cybersecurity, digital security, or information technology (IT) security) is a subdiscipline within the field of information security. It consists of the protection of computer software, systems and computer network, networks from Threat (security), threats that can lead to unauthorized information disclosure, theft or damage to computer hardware, hardware, software, or Data (computing), data, as well as from the disruption or misdirection of the Service (economics), services they provide. The significance of the field stems from the expanded reliance on computer systems, the Internet, and wireless network standards. Its importance is further amplified by the growth of smart devices, including smartphones, televisions, and the various devices that constitute the Internet of things (IoT). Cybersecurity has emerged as one of the most significant new challenges facing the contemporary world, due to both the complexity of information systems and the societi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux Kernel
The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the kernel for the GNU operating system (OS) which was created to be a free software, free replacement for Unix. Since the late 1990s, it has been included in many Linux distributions, operating system distributions, many of which are called Linux. One such Linux kernel operating system is Android (operating system), Android which is used in many mobile and embedded devices. Most of the kernel code is written in C (programming language), C as supported by the GNU compiler collection (GCC) which has extensions beyond standard C. The code also contains assembly language, assembly code for architecture-specific logic such as optimizing memory use and task execution. The kernel has a Modular programming, modular design such that modules can be inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMD K6
The K6 microprocessor was launched by AMD in 1997. The main advantage of this particular microprocessor is that it was designed to fit into existing desktop designs for Pentium-branded CPUs. It was marketed as a product that could perform as well as its Intel Pentium II equivalent but at a significantly lower price. The K6 had a considerable impact on the PC market and presented Intel with serious competition. Background The AMD K6 is a superscalar P5 Pentium-class microprocessor, manufactured by AMD, which superseded the K5. The AMD K6 is based on the Nx686 microprocessor that NexGen was designing when it was acquired by AMD. Despite the name implying a design evolving from the K5, it is in fact a totally different design that was created by the NexGen team, including chief processor architect Greg Favor, and adapted after the AMD purchase. The K6 processor included a feedback dynamic instruction reordering mechanism, MMX instructions, and a floating-point unit (FPU). It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentium M
The Pentium M is a family of mobile 32-bit single-core x86 microprocessors (with the modified Intel P6 (microarchitecture), P6 microarchitecture) introduced in March 2003 and forming a part of the Intel Centrino#Carmel platform (2003), Carmel notebook platform under the then new Centrino brand. The ''Pentium M'' processors had a maximum thermal design power (TDP) of 5–27 W depending on the model, and were intended for use in laptops (thus the "M" suffix standing for ''mobile''). They evolved from the core of the last Pentium III–branded CPU by adding the front-side bus (FSB) interface of Pentium 4, an improved instruction decoding and issuing front end, improved branch predictor, branch prediction, SSE2 support, and a much larger cache. The Pentium M replaced the laptop version of the Pentium 4 (the ''Pentium 4-Mobile'', or ''P4-M''), which suffered from power consumption and heat problems. The first Pentium M–branded CPU, code-named Banias, was followed by Dothan. The Pent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celeron M
Celeron is a series of IA-32 and x86-64 computer microprocessors targeted at low-cost personal computers, manufactured by Intel from 1998 until 2023. The first Celeron-branded CPU was introduced on April 15, 1998, and was based on the Pentium II. Celeron-branded processors released from 2009 to 2023 are compatible with IA-32 software. They typically offer less performance per clock speed compared to flagship Intel CPU lines, such as the Pentium or Core brands. They often have less cache or intentionally disabled advanced features, with variable impact on performance. While some Celeron designs have achieved strong performance for their segment, the majority of the Celeron line has exhibited noticeably degraded performance. This has been the primary justification for the higher cost of other Intel CPU brands versus the Celeron range. In September 2022, Intel announced that the Celeron brand, along with Pentium, were to be replaced with the new "Intel Processor" branding for l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentium Pro
The Pentium Pro is a sixth-generation x86 microprocessor developed and manufactured by Intel and introduced on November 1, 1995. It implements the P6 (microarchitecture), P6 microarchitecture (sometimes termed i686), and was the first x86 Intel CPU to do so. The Pentium Pro was originally intended to replace the original Pentium (original), Pentium in a full range of applications. Later, it was reduced to a more narrow role as a server and high-end desktop processor. The Pentium Pro was also used in supercomputers, most notably ASCI Red, which was the first computer to reach over one teraFLOPS in 1996 and held the number one spot in the TOP500 list from 1997 to 2000. ASCI Red used two Pentium Pro CPUs on each computing node. While the Pentium and Pentium MMX had 3.1 and 4.5 million transistors, respectively, the Pentium Pro contained 5.5 million transistors. It was capable of both dual- and quad-processor configurations and only came in one form factor, the relatively l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Address Extension
In computing, Physical Address Extension (PAE), sometimes referred to as Page Address Extension, is a memory management feature for the x86 architecture. PAE was first introduced by Intel in the Pentium Pro, and later by AMD in the Athlon processor. It defines a page table hierarchy of three levels (instead of two), with table entries of 64 bits each instead of 32, allowing these CPUs to directly access a physical address space larger than 4 gigabytes (232 bytes). The page table structure used by x86-64 CPUs when operating in long mode further extends the page table hierarchy to four or more levels, extending the virtual address space, and uses additional physical address bits at all levels of the page table, extending the physical address space. It also uses the topmost bit of the 64-bit page table entry as a no-execute or "NX" bit, indicating that code cannot be executed from the associated page. The NX feature is also available in protected mode when these CPUs are run ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenSUSE
openSUSE () is a free and open-source software, free and open-source Linux distribution developed by the openSUSE project. It is offered in two main variations: ''Tumbleweed'', an upstream rolling release distribution, and ''Leap'', a stable release distribution which is sourced from SUSE Linux Enterprise. The openSUSE project is sponsored by SUSE S.A., SUSE of Germany; the company released the first version as SUSE Linux in 1994. Its development was opened up to the community in 2005, which marked the creation of openSUSE. The focus of the developers is on creating a stable and user-friendly RPM Package Manager, RPM-based operating system with a large target group for workstations and Server (computing), servers. Additionally, the project creates a variety of related tools, such as YaST, Open Build Service, openQA, Snapper, Portus, KIWI (openSUSE), KIWI, and OSEM. Product history SUSE Linux In the past, the SUSE Linux company has focused on releasing the SUSE Linux Perso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ubuntu (operating System)
Ubuntu ( ) is a Linux distribution based on Debian and composed primarily of free and open-source software. Developed by the British company Canonical and a community of contributors under a meritocratic governance model, Ubuntu is released in multiple official editions: ''Desktop'', '' Server'', and ''Core'' for IoT and robotic devices. Ubuntu is published on a six-month release cycle, with long-term support (LTS) versions issued every two years. Canonical provides security updates and support until each release reaches its designated end-of-life (EOL), with optional extended support available through the Ubuntu Pro and Expanded Security Maintenance (ESM) services. , the latest stable release is 25.04 ("Plucky Puffin"), and the current LTS release is 24.04 ("Noble Numbat"). Ubuntu can be installed directly on hardware or run within a virtual machine. It is widely used for cloud computing, with integration support for platforms such as OpenStack. It is also one of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fedora Linux
Fedora Linux is a Linux distribution developed by the Fedora Project. It was originally developed in 2003 as a continuation of the Red Hat Linux project. It contains software distributed under various free and open-source licenses and aims to be on the leading edge of open-source technologies. It is now the upstream source for CentOS Stream and Red Hat Enterprise Linux. Since the release of Fedora 21 in December 2014, three editions have been made available: personal computer, server and cloud computing. This was expanded to five editions for containerization and Internet of Things (IoT) as of the release of Fedora 37 in November 2022. A new version of Fedora Linux is released every six months. , Fedora Linux has an estimated 1.2 million users, and is also the distribution used by Linus Torvalds, creator of the Linux kernel (). Features Fedora has a reputation for focusing on innovation, integrating new technologies early on and working closely with upstream Linux commun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux Distribution
A Linux distribution, often abbreviated as distro, is an operating system that includes the Linux kernel for its kernel functionality. Although the name does not imply product distribution per se, a distro—if distributed on its own—is often obtained via a website intended specifically for the purpose. Distros have been designed for a wide variety of systems ranging from personal computers (for example, Linux Mint) to servers (for example, Red Hat Enterprise Linux) and from embedded devices (for example, OpenWrt) to supercomputers (for example, Rocks Cluster Distribution). A distro typically includes many components in addition to the Linux kernel. Commonly, it includes a package manager, an init system (such as systemd, OpenRC, or runit), GNU tools and libraries, documentation, IP network configuration utilities, the getty TTY setup program, and many more. To provide a desktop experience (most commonly the Mesa userspace graphics drivers) a display server (the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IA-64
IA-64 (Intel Itanium architecture) is the instruction set architecture (ISA) of the discontinued 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 cycle. In 2008, Itanium was the fourth-most deployed microprocessor architecture for enterprise-class systems, behind x86-64, Power ISA, and SPARC. In 2019, Intel announced the discontinuation of the last of the CPUs supporting the IA-64 architecture. Microsoft Win ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
