13.4. Kernel Interaction During Boot

Once the kernel is loaded by either the default loader (Section 13.3.3, “Stage Three, /boot/loader) or by boot2 (Section 13.3.2, “Stage One, /boot/boot1, and Stage Two, /boot/boot2), which bypasses the loader, it examines any boot flags 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.


Refer to boot(8) for more information on the other boot flags.

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