13.4 Kernel Interaction During Boot

Once the kernel is loaded by either loader (as usual) or boot2 (bypassing the loader), it examines its boot flags, if any, and adjusts its behavior as necessary.

13.4.1 Kernel Boot Flags

Here are the more common boot flags:


during kernel initialization, ask for the device to mount as the root file system.


boot from CDROM.


run UserConfig, the boot-time kernel configurator


boot into single-user mode


be more verbose during kernel startup

Note: There are other boot flags, read boot(8) for more information on them.