009 Embedded Linux-ARM. StorageQueries and discussion related to usage of Linux on ARM based devices. Linux has been ported to a variety of CPUs which are not only primarily used as the processor of a desktop or server computer, but also ARM, AVR32, ETRAX CRIS, FR-V, H8300, IP7000, m68k, MIPS, mn10300, SuperH, and Xtensa processors, It is also used as an alternative to using a proprietary operating system and toolchain. » 009.04.Boot Loaders
009.04.91.9. Can you explain the significance of the `grub.cfg`, `/etc/default/grub`, and `/etc/grub.d/` files in the GRUB2 configuration process? How do these files interact to determine the boot behavior of the system, and what are the key settings that system administrators typically adjust in each of these files?
grub.cfg is the main configuration file from where grub2 reads during the boot. It is generated automatically by running grub-mkconfig command, which compiles configuration details from various sources.
/etc/default/grub contains the global settings for GRUB2, such as the default menu entry, timeout duration, and kernel parameters. Changes here affect the overall behavior of the bootloader.
/etc/grub.dcontains scripts that are executed in sequencewhen grub-mkconfig is run. These scripts generate menu entries for each installed kernel and operating system, along with the custom entries and advanced options.
The
The key settings that the system administrators adjust in each of these files is:-
GRUB_DEFAULT : It specifies the default menu entry, either by number,saved state, or menu entry title.
GRUB_TIMEOUT : It specifies amount of time before the default entry is automatically booted.
GRUB_CMDLINE_LINUX_DEFAULT : Adds additional kernel parameters that are applied to all linux menu entries.
GRUB_BACKGROUND : Allows the setting of a background image for the grub menu.
GRUB_THEME : Specifies a graphical theme for the menu, enhancing the visual interface.