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Active Partition
A boot flag is a 1-byte value in a non-extended partition record, within a master boot record. It appears at the beginning of a partition record, as the value 0x80. A value of 0x00 indicates the partition does not have the boot flag set. Any other value is invalid. Its primary function is to indicate to a MS-DOS/MS Windows-type boot loader which partition to boot. In some cases it is used by Windows XP/2000 to assign the active partition the letter "C:". The active partition is the partition where the boot flag is set. DOS and Windows allow only one boot partition to be set with the boot flag. Other boot loaders used by third-party boot managers (such as GRUB or XOSL) can be installed to a master boot record and can boot primary or extended partitions, which do not have the boot flag set. There are many disk editors that can modify the boot flag, such as Disk Management in Windows, GPartEd in Linux, and fdisk. Some BIOSes test if the boot flag of at least one partition is set, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as the Internet Protocol () refer to an 8-bit byte as an octet. Those bits in an octet are usually counted with numbering from 0 to 7 or 7 to 0 depending on the bit endianness. The size of the byte has historically been hardware-dependent and no definitive standards existed that mandated the size. Sizes from 1 to 48 bits have been used. The six-bit character code was an often-used implementation in early encoding systems, and computers using six-bit and nine-bit bytes were common in the 1960s. These systems often had memory words of 12, 18, 24, 30, 36, 48, or 60 bits, corresponding t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extended Boot Record
An extended boot record (EBR), or extended partition boot record (EPBR), is a descriptor for a logical partition under the common DOS disk drive partitioning system. In that system, when one (and only one) partition record entry in the master boot record (MBR) is designated an ''extended partition'', then that partition can be subdivided into a number of logical partitions. The actual structure of that extended partition is described by one or more EBRs, which are located inside the extended partition. The first (and sometimes only) EBR will always be located on the first sector of the extended partition. Unlike primary partitions, which are all described by a single partition table within the MBR, and thus limited in number, each EBR precedes the logical partition it describes. If another logical partition follows, then the first EBR will contain an entry pointing to the next EBR; thus, multiple EBRs form a linked list. This means the number of logical drives that can be formed wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BIOS
In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process (power-on startup). The firmware comes pre-installed on the computer's motherboard. The name originates from the Basic Input/Output System used in the CP/M operating system in 1975. The BIOS firmware was originally proprietary to the IBM PC; it was reverse engineered by some companies (such as Phoenix Technologies) looking to create compatible systems. The interface of that original system serves as a ''de facto'' standard. The BIOS in older PCs initializes and tests the system hardware components ( power-on self-test or POST for short), and loads a boot loader from a mass storage device which then initializes a kernel. In the era of DOS, the BIOS provided BIOS interrupt calls for the keyboard, display, st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Partitioning
Disk partitioning or disk slicing is the creation of one or more regions on secondary storage, so that each region can be managed separately. These regions are called partitions. It is typically the first step of preparing a newly installed disk after a partitioning scheme is chosen for the new disk before any file system is created. The disk stores the information about the partitions' locations and sizes in an area known as the partition table that the operating system reads before any other part of the disk. Each partition then appears to the operating system as a distinct "logical" disk that uses part of the actual disk. System administrators use a program called a partition editor to create, resize, delete, and manipulate the partitions. Partitioning allows the use of different filesystems to be installed for different kinds of files. Separating user data from system data can prevent the system partition from becoming full and rendering the system unusable. Partitioning can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fdisk
fdisk is a command-line utility for disk partitioning. It has been part of DOS, DR FlexOS, IBM OS/2, and early versions of Microsoft Windows, as well as certain ports of FreeBSD, NetBSD, OpenBSD, DragonFly BSD and macOS for compatibility reasons. Windows 2000 and its successors have replaced fdisk with a more advanced tool called diskpart. Implementations DOS IBM introduced the first version of fdisk (officially dubbed "Fixed Disk Setup Program") in March 1983, with the release of the IBM PC/XT computer (the first PC to store data on a hard disk) and the IBM PC DOS 2.0 operating system. fdisk version 1.0 can create one FAT12 partition, delete it, change the active partition, or display partition data. fdisk writes the master boot record, which supports up to four partitions. The other three were intended for other operating systems such as CP/M-86 and Xenix, which were expected to have their own partitioning utilities. Microsoft first added fdisk to MS-DOS in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, packaged as a Linux distribution (distro), which includes the kernel and supporting system software and library (computing), libraries—most of which are provided by third parties—to create a complete operating system, designed as a clone of Unix and released under the copyleft GPL license. List of Linux distributions, Thousands of Linux distributions exist, many based directly or indirectly on other distributions; popular Linux distributions include Debian, Fedora Linux, Linux Mint, Arch Linux, and Ubuntu, while commercial distributions include Red Hat Enterprise Linux, SUSE Linux Enterprise, and ChromeOS. Linux distributions are frequently used in server platforms. Many Linux distributions use the word "Linux" in their name, but the Free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPartEd
GParted is a GTK front-end to GNU Parted and an official GNOME partition-editing application (alongside GNOME Disks, Disks). GParted is used for creating, deleting, resizing, moving, checking, and copying Partition (computing), disk partitions and their file systems. This is useful for creating space for new operating systems, reorganizing disk usage, copying data residing on hard disks, and mirroring one partition with another (disk imaging). It can also be used to format a USB drive. Background GParted uses GNU Parted, libparted to detect and manipulate devices and partition tables while several (optional) file system tools provide support for file systems not included in libparted. These optional packages will be detected at runtime and do not require a rebuild of GParted. GParted supports the following filesystems: Ext2, Ext3, Ext4, FAT16, Fat32, FAT32, Hierarchical File System (Apple), HFS, HFS Plus, HFS+, JFS (file system), JFS, Linux swap, Linux-swap, ReiserFS, Reiser4, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft
Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The early 1980s and home computers, rise of personal computers through software like Windows, and the company has since expanded to Internet services, cloud computing, video gaming and other fields. Microsoft is the List of the largest software companies, largest software maker, one of the Trillion-dollar company, most valuable public U.S. companies, and one of the List of most valuable brands, most valuable brands globally. Microsoft was founded by Bill Gates and Paul Allen to develop and sell BASIC interpreters for the Altair 8800. It rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Windows. During the 41 years from 1980 to 2021 Microsoft released 9 versions of MS-DOS with a median frequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Editor
A disk editor is a computer program that allows its user to read, edit, and write raw data (at character or hexadecimal, byte-levels) on disk drives (e.g., hard disks, USB flash disks or removable media such as a floppy disks); as such, they are sometimes called ''sector editors,'' since the read/write routines built into the electronics of most disk drives require to read/write data in chunks of sectors (usually 512 bytes). Many disk editors can also be used to edit the contents of a running computer's memory or a disk image. Unlike ''hex editors,'' which are used to edit files, a disk editor allows access to the underlying disk structures, such as the master boot record (MBR) or GUID Partition Table (GPT), file system, and directories. On some operating systems (like Unix or Unix-like) most hex editors can act as disk editors just opening block devices instead of regular files. Programmers can use disk editors to understand these structures and test whether their implement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XOSL
xOSL (meaning Extended Operating System Loader) is a bootloader. xOSL was originally developed by Geurt Vos. Additional layout design by Dan Duskin, and graphical logo by Mark Monciardini. History xOSL is free software released under the GPL-2.0-only license. The project was actively developed by Geurt Vos between 1999 and 2001 and spanned four major revisions and two minor revisions after its initial creation. From its origin in xOSL version 1.0.0, xOSL underwent major changes in ver. 1.1.0, 1.1.1, 1.1.2 and 1.1.3. These revisions were significant departures from one another, and introduced new features to the program. These features ranged from drastic user interface improvements to improved compatibility on diverse hardware platforms. xOSL ver. 1.1.4 and 1.1.5 only introduced improvements to existing functionality and repaired features that should have been functional in their predecessors. Although their improvements were subtle, they did serve to stabilize a developing pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Master Boot Record
A master boot record (MBR) is a type of boot sector in the first block of disk partitioning, partitioned computer mass storage devices like fixed disks or removable drives intended for use with IBM PC-compatible systems and beyond. The concept of MBRs was publicly introduced in 1983 with PC DOS 2.0. The MBR holds the information on how the disc's sectors (A.K.A. "blocks") are divided into partitions, each partition notionally containing a file system. The MBR also contains executable code to function as a loader for the installed operating system—usually by passing control over to the loader's second stage, or in conjunction with each partition's volume boot record (VBR). This MBR code is usually referred to as a boot loader. The organization of the partition table in the MBR limits the maximum addressable storage space of a partitioned disk to 2 Tebibyte, TiB . Approaches to slightly raise this limit utilizing 32-bit arithmetic or 4096-byte sectors are not officially s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GRUB
GNU GRUB (short for GNU GRand Unified Bootloader, commonly referred to as GRUB) is a boot loader package from the GNU Project. GRUB is the reference implementation of the Free Software Foundation's Multiboot Specification, which provides a user the choice to boot one of multiple operating systems installed on a computer set up for multi-booting or select a specific kernel configuration available on a particular operating system's partitions. GNU GRUB was developed from a package called the ''Grand Unified Bootloader'' (a play on Grand Unified Theory). It is predominantly used for Unix-like systems. Operation Booting When a computer is turned on, its BIOS finds the primary bootable device (usually the computer's hard disk) and runs the initial bootstrap program from the master boot record (MBR). The MBR is the first sector of the hard disk. This bootstrap program must be small because it has to fit in a single sector. For a long time, the size of a sector has been 512&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
