The Linux boot process refers to the sequence of events that occur when a Linux system is started up. There are several steps involved in this process, including the loading of the bootloader, the kernel, and the initial ramdisk.
One common bootloader used in Linux systems is GRUB (GRand Unified Bootloader). GRUB is responsible for loading the Linux kernel and initial ramdisk, as well as providing a menu of boot options for the user to choose from.
When a Linux system is powered on, the BIOS (Basic Input/Output System) or UEFI (Unified Extensible Firmware Interface) system performs a series of checks and initializes the hardware. The BIOS or UEFI system then looks for a bootable device, such as a hard drive or USB drive, and transfers control to the bootloader on that device.
Once the bootloader is loaded, it displays a menu of boot options to the user. This menu can include options such as "normal boot,""recovery mode," or "safe mode." The user can select an option using their keyboard or the default option will be selected after a certain amount of time has passed.
Once the user has selected an option, the bootloader loads the Linux kernel and initial ramdisk into memory. The kernel is responsible for starting the operating system and initializing the hardware. The initial ramdisk is a small file system that contains necessary files and drivers needed to boot the system.
After the kernel and initial ramdisk are loaded, the boot process is handed over to the init system, which is responsible for starting other processes and services necessary for the system to function.
In summary, the Linux boot process involves the loading of the BIOS or UEFI system, the bootloader, the kernel, and the initial ramdisk, and the initialization of the init system. GRUB2 is a commonly used bootloader in Linux systems, and can provide a menu of boot options for the user to choose from.