bootmgr — tool for configuring Kernun boot manager


bootmgr [-x] [-d { 1 | 2 | 3 } ] [ -u | -n ] [-1 label | + | - ] [-2 label | + | - ] [-3 label | + | - ] [dev]


Utility bootmgr can be used to view or change configuration of the Kernun boot manager. If invoked without command line parameters, the boot manager configuration is displayed in a text format. If only option -x is specified, the boot manager configuration is displayed in XML. Other command line options set various parameters of the boot manager.

The boot manager displays a boot menu that allows to boot one from up to three installations (in the first three disk slices) of the Kernun firewall. For security reasons, the administrator can disable some menu choices. There is always a default selection, that is booted after a timeout if no key is pressed. It is configurable whether selection of a non-default choice changes the default for next reboots or not.

The Kernun boot manager is a slightly modified FreeBSD boot manager. It is installed by the Kernun installation process into the MBR (Master Boot Record) of the system disk. It can be reinstalled by boot0cfg(8), but this is almost never needed. The main difference from the FreeBSD loader is the boot menu. Instead of slice types, it shows changeable labels of individual Kernun installation. There are two variants of the boot manager boot0 and boot0ext, stored in directory /usr/local/kernun/lib. The preferred variant is boot0ext, which is two sectors (1024 B) long. It has space for 74 character labels. By default, a label contains a Kernun version identification, including a full build number, and the date and time of the installation. The smaller, one sector (512 B) variant boot0 has space for ony 9 character labels. By default a label contains date and time of the Kernun installation.



Displays boot manager configuration in XML.

-d {1 | 2 | 3}

the default slice to boot from


Selection from the boot menu will update the default choice.


Selection from the boot menu will leave the default choice unchanged.

-1 label

-2 label

-3 label

Changes a label of a menu item.

-1 +

-2 +

-3 +

Enables a menu item and booting from the corresponding slice.

-1 -

-2 -

-3 -

Disables a menu item and booting from the corresponding slice. Use with caution, as disabling all working Kernun installations will render the system unable to boot. In such situation, the boot manager may be reconfigured using the installation medium.


Operates on the boot manager located on this disk device. If not used, the disk containing the root file system is selected.



The one sector boot manager; deprecated, because it has only 9 characters for each boot menu item.


The two sectors boot manager; preferred, with 74 characters for each boo menu item.

See Also

boot0cfg(8), boot(8), fdisk(8)


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