Linux 5 guiding process 3 [grub + Summary]

The default configuration file of grubgrub is/boot/GRUB/grub. conf/etc soft chain # ls-L/etc/grub. conf kernel exists under/boot grub configuration option default definition default startup system timeout definition default wait time splashimage definition gurb interface image hiddenmenu hidden menu title definition menu item name root SET grub root device that is the kernel partition kernel defines the location of the kernel file. The initrd command loads the image file grub command function key: e: edit the current menu item C: Enter the command line mode of grub B: Start the current menu item D: Delete the current line ESC: Return to the grub Startup menu interface, cancel any modifications made to the current single item Linux boot process knowledge point summary #1 master each step of the Linux boot process firmware CMOS/BIOS [PC] [if there is no problem, read the hard disk first MBR, here is a UDF] | bootloader grub [most ilinux is grub] root-/boot kernel-initrd-| kernel hardware | init pid = 1 constant pid = 0 inter-process switchover and time allocation |/etc/inittab ID: runlevels: Action: process [What is the most important thing] | initdefault 1 single 23 5x11 0 halt 6 reboot 4 [reserved] init [this command can switch the running level] |/etc/rc. d/RC. sysinit [execute this script at any running level] |/etc/rc. d/RC [How to boot later, execute the script] |/etc/rc. d/rcN. d [How to boot later, execute this script] S-start k-kill | Username Password description 1: three options are defined under the title of the Network Time Protocol ntp OS system, description 2: # Man grep | col-B> grep. man. View help.