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MKINITRD(8)	       DragonFly System Manager's Manual	   MKINITRD(8)

NAME
     mkinitrd -- build an initial ramdisk image for use as early userland

SYNOPSIS
     mkinitrd [-b bootdir] [-t tmpdir]

DESCRIPTION
     The mkinitrd script builds a ramdisk (md) image based on the UFS filesys-
     tem containing only the most basic tools, such as a minimal init(8),
     sh(1) as well as many mount(8) utilities.

     It will also copy the contents of /usr/share/initrd onto the ramdisk,
     maintaining the same hierarchy.

     On completion, the final image will be copied to /boot/kernel/initrd.img,
     ready to be used as an early userland.  The base directory for
     kernel/initrd.img can be changed with the -b option to an optional
     bootdir (the default is /boot).  The temporary directory to be used for
     setting up the image can be specified using the -t option (the default is
     /tmp).

     The mkinitrd script will read /etc/mkinitrd.conf if it exists and use the
     configuration from this file to override the following variables
     (defaults are in /etc/defaults/mkinitrd.conf):

	   BUILD_DIR
	   INITRD_SIZE
	   BIN_TOOLS
	   SBIN_TOOLS
	   INITRD_DIRS
	   CONTENT_DIRS

     Adding the following lines to /boot/loader.conf will enable the use of
     the created initrd image:

	   initrd.img_load="YES"
	   initrd.img_type="md_image"
	   vfs.root.mountfrom="ufs:md0s0"

     The format for vfs.root.realroot in /boot/loader.conf that allows the
     user to specify what system to mount as the new root in the initrd is
     specified in its general form below:

	   vfs.root.realroot="<type>:[arg1[:arg2[:argN]]]"

     Currently, three types of real root are supported, local, tcplay and
     crypt.  The local type allows to mount any local file system that does
     not require any special setup apart from the initial discovery and call-
     ing the mount program. The general format is as follows:

	   vfs.root.realroot="local:<FS TYPE>:<DEVICE PATH>[:<OPTIONS>]"

     The crypt type allows to mount volumes supported by cryptsetup. The
     device will be set up by prompting the user for his key, and this volume
     will then be mounted as the new root.

	   vfs.root.realroot="crypt:<FS TYPE>:<DEVICE PATH>:<VOLUME NAME>[:<OPTIONS>]"

     The tcplay type allows to mount volumes supported by tcplay(8).  The
     device will be set up by prompting the user for his key, and this volume
     will then be mounted as the new root.

	   vfs.root.realroot="tcplay:<FS TYPE>:<DEVICE PATH>:<VOLUME NAME>[:<OPTIONS>]"

EXAMPLES
	   vfs.root.realroot="local:ufs:/dev/vg00/lv0[:OPTIONS]"

	   vfs.root.realroot="crypt:ufs:/dev/ad0s0a:secvolume[:OPTIONS]"

SEE ALSO
     md(4), loader.conf(5)

HISTORY
     The mkinitrd command first appeared in DragonFly 2.7.

AUTHORS
     mkinitrd was written by Alex Hornung <ahornung@gmail.com>.

DragonFly 3.5		       December 12, 2011		 DragonFly 3.5