GoboLinux is an open source operating system whose most prominent feature is a reorganization of the traditional Linux file system. Rather than following the Filesystem Hierarchy Standard like most Unix-like systems, each program in a GoboLinux system has its own subdirectory tree, where all of its files may be found. Thus, a program "Foo" has all of its specific files and libraries in /Programs/Foo, under the corresponding version of this program at hand. For example, the commonly known GCC compiler suite version 8.1.0, would reside under the directory /Programs/GCC/8.1.0.
The Filesystem Hierarchy Standard (FHS) is a reference describing the conventions used for the layout of a UNIX system. It has been made popular by its use in GNU/Linux distributions, but it is used by other UNIX variants as well. It is maintained by the Linux Foundation. The latest version is 3.0, released on 3 June 2015.
LILO is a boot loader for Linux and was the default boot loader for most Linux distributions in the years after the popularity of loadlin. Today, many distributions use GRUB as the default boot loader, but LILO and its variant ELILO are still in wide use. Further development of LILO was discontinued in December 2015 along with a request by Joachim Wiedorn for potential developers.
GNU 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 or select a specific kernel configuration available on a particular operating system's partitions.
In computing, a loadable kernel module (LKM) is an object file that contains code to extend the running kernel, or so-called base kernel, of an operating system. LKMs are typically used to add support for new hardware and/or filesystems, or for adding system calls. When the functionality provided by an LKM is no longer required, it can be unloaded in order to free memory and other resources.
The Unified Extensible Firmware Interface (UEFI) is a publicly available specification that defines a software interface between an operating system and platform firmware. UEFI replaces the legacy Basic Input/Output System (BIOS) firmware interface originally present in all IBM PC-compatible personal computers, with most UEFI firmware implementations providing support for legacy BIOS services. UEFI can support remote diagnostics and repair of computers, even with no operating system installed.
vmlinux is a statically linked executable file that contains the Linux kernel in one of the object file formats supported by Linux, which includes Executable and Linkable Format (ELF), Common Object File Format (COFF) and a.out. The vmlinux file might be required for kernel debugging, symbol table generation or other operations, but must be made bootable before being used as an operating system kernel by adding a multiboot header, bootsector and setup routines.
A Hackintosh is a computer that runs Apple's Macintosh operating system macOS on computer hardware not authorized for the purpose by Apple. "Hackintoshing" began as a result of Apple's 2005 transition to Intel processors, away from PowerPC. Since 2005, Mac computers use the same x86-64 computer architecture as many other desktop PCs, laptops, notebooks and servers, meaning that in principle, the code making up macOS systems and software can be run on alternative platforms with minimal compatibility issues. Benefits cited for "Hackintoshing" can include cost, ease of repair and piecemeal upgrade, and freedom to use customized choices of components that are not available in the branded Apple products. macOS can also be run on several non-Apple virtualization platforms, although such systems are not usually described as Hackintoshes. Hackintosh laptops are sometimes referred to as "Hackbooks". In recent years, the use of AMD processors has become common in Hackintoshes, thanks to the website AMD OS X. The popularity is due to the introduction of the powerful AMD Ryzen and Threadripper CPUs.
The GUID Partition Table (GPT) is a standard for the layout of partition tables of a physical computer storage device, such as a hard disk drive or solid-state drive, using universally unique identifiers, which are also known as globally unique identifiers (GUIDs). Forming a part of the Unified Extensible Firmware Interface (UEFI) standard, it is nevertheless also used for some BIOS systems, because of the limitations of master boot record (MBR) partition tables, which use 32 bits for logical block addressing (LBA) of traditional 512-byte disk sectors.
In Linux systems, initrd is a scheme for loading a temporary root file system into memory, to be used as part of the Linux startup process. initrd and initramfs refer to two different methods of achieving this. Both are commonly used to make preparations before the real root file system can be mounted.
The Apple–Intel architecture, or Mactel, is an unofficial name used for Apple Macintosh personal computers developed and manufactured by Apple Inc. that use Intel x86 processors, rather than the PowerPC and Motorola 68000 ("68k") series processors used in their predecessors or the ARM processors used in their successors. With the change in architecture, a change in firmware became necessary; Apple selected the Intel-designed Extensible Firmware Interface (EFI) as its comparable component to the Open Firmware used on its PowerPC architectures, and as the firmware-based replacement for the PC BIOS from Intel. With the change in processor architecture to x86, Macs gained the ability to boot into x86-native operating systems, while Intel VT-x brought near-native virtualization with Mac OS X as the host OS.
A live USB is a portable USB-attached external data storage device containing a full operating system that can be booted from. The term is reminiscent of USB flash drives but may encompass an external hard disk drive or solid-state drive, though they may be referred to as "live HDD" and "live SSD" respectively. They are the evolutionary next step after live CDs, but with the added benefit of writable storage, allowing customizations to the booted operating system. Live USBs can be used in embedded systems for system administration, data recovery, or test driving, and can persistently save settings and install software packages on the USB device.
The EFIsystem partition or ESP is a partition on a data storage device that is used by computers having the Unified Extensible Firmware Interface (UEFI). When a computer is booted, UEFI firmware loads files stored on the ESP to start installed operating systems and various utilities.
Linux startup process is the multi-stage initialization process performed during booting a Linux installation. It is in many ways similar to the BSD and other Unix-style boot processes, from which it derives.
kexec, abbreviated from kernel execute and analogous to the Unix/Linux kernel call exec, is a mechanism of the Linux kernel that allows booting of a new kernel from the currently running one. Essentially, kexec skips the bootloader stage and hardware initialization phase performed by the system firmware, and directly loads the new kernel into main memory and starts executing it immediately. This avoids the long times associated with a full reboot, and can help systems to meet high-availability requirements by minimizing downtime.
gPXE is an open-source Preboot eXecution Environment (PXE) client firmware implementation and bootloader derived from Etherboot. It can be used to enable computers without built-in PXE support to boot from the network, or to extend an existing client PXE implementation with support for additional protocols. While standard PXE clients use TFTP to transfer data, gPXE client firmware adds the ability to retrieve data through other protocols like HTTP, iSCSI and ATA over Ethernet (AoE), and can work with Wi-Fi rather than requiring a wired connection.
A master boot record (MBR) is a special type of boot sector at the very beginning of 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.
systemd-boot, formerly known as gummiboot, is a free and open-source boot manager. It was created when gummiboot was merged into systemd and renamed to "systemd-boot" in May 2015.
Kay Sievers is a computer programmer, best known for developing the udev device manager of Linux, systemd and the Gummiboot EFI bootloader. Kay Sievers made major contributions to Linux's hardware hotplug and device management subsystems. In 2012, together with Harald Hoyer, Sievers was the main driving force behind Fedora's merging of the /lib, /bin and /sbin file-system trees into /usr, a simplification which other distributions such as Arch Linux have since adopted.
rEFInd is a boot manager for UEFI and EFI-based machines. It can be used to boot multiple operating systems that are installed on a single non-volatile device. It also provides a way to launch UEFI applications.
