Chapter 6 Study Cards Flashcards
Boot loader
Software, usually installed on the MBR of Intel machines, which exists to load the operating system kernel and begin its functioning.
Boot manager
A program that enables the user to select an OS to run at system boot time. The boot manager then launches a boot loader to handle this task. Most boot loaders for Linux on BIOS-based computers combine boot loader and boot manager functionality in one program, so the two terms are sometimes used interchangeably.
Boot sector
A disk sector from which a BIOS reads boot loader code. Typically, the first sector of a disk or partition can function as a boot sector. Unlike BIOS, EFI does not rely on boot sectors.
EFI
A type of firmware intended to replace the three decades-old BIOS. Like the BIOS, the EFI handles low-level system startup and OS launching procedures. See also Unified Extensible Firmware Interface (UEFI).
EFI System Partition (ESP)
A partition, prepared with a FAT filesystem, on which EFI looks for boot loaders, drivers, and similar low-level boot files.
Extensible Firmware Interface (EFI)
A type of firmware intended to replace the three decades-old BIOS. Like the BIOS, the EFI handles low-level system startup and OS launching procedures. See also Unified Extensible Firmware Interface (UEFI).
Fireware
Firmware
A type of software that’s traditionally stored in chips on a hardware device in order to control its lowest-level functions. Motherboard firmware is particularly important. The Basic Input/Output System (BIOS) has traditionally been the most common type of motherboard firmware for desktop and laptop computers, but the Extensible Firmware Interface (EFI) has exploded in popularity beginning in 2011.
GRUB
A boot loader: a program that loads the kernel so Linux can boot; can also boot other operating systems.
Kernel ring buffer
A record of recent messages generated by the Linux kernel. Immediately after a Linux system boots, this buffer contains the bootup messages generated by drivers and major kernel subsystems. This buffer may be viewed with the dmesg command.
LILO
A boot loader: a program that loads the kernel so Linux can boot; can also boot other operating systems.
MBR
MBR
An area of the outermost cylinder of a PC hard disk which contains the partition table. This contains four entries identifying the types, starting cylinder and sizes of up to four partitions on the hard disk. One of the entries is flagged as ‘active’; this marks the partition from which the machine will boot. (Floppy disks don’t have an MBR, since they don’t have a partition table. Instead, they just have a boot sector (same as a logical disk), which contains a Media Descriptor Table (MDT) and bootstrap loader. The MDT describes the format of a floppy disk or logical disk).
Mode
The permissions of a file. In conjunction with the file’s owner and group, the mode determines who may access a file and in what ways.
Runlevel
Mode of operation of a Unix system, offering different services on each level. Runlevels are numbered from 0 to 6, and each one is assigned a set of services that should be active. Upon booting, Linux enters a predetermined runlevel, which you can set. Knowing what these functions are, and how to manage runlevels, is important if you’re to control the Linux boot process and ongoing operations.
Superblock
A filesystem (meaning 1) data structure that holds critical information about the filesystem, such as its size and revision number.
System V (SysV)
A form of AT&T Unix that defined many of the standards used on modern Unix systems and Unix clones, such as Linux.
