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LOADER.CONF(5)		  FreeBSD File Formats Manual		LOADER.CONF(5)

     loader.conf -- system bootstrap configuration information

     The file loader.conf contains descriptive information on bootstrapping
     the system.  Through it you can specify the kernel	to be booted, parame-
     ters to be	passed to it, and additional modules to	be loaded; and gener-
     ally set all variables described in loader(8).

     Though loader.conf's format was defined explicitly	to resemble
     rc.conf(5), and can be sourced by sh(1), some settings are	treated	in a
     special fashion.  Also, the behavior of some settings is defined by the
     setting's suffix; the prefix identifies which module the setting con-

     The general parsing rules are:

     o	 Spaces	and empty lines	are ignored.

     o	 A # sign will mark the	remainder of the line as a comment.

     o	 Only one setting can be present on each line.

     All settings have the following format:


     Unless it belongs to one of the classes of	settings that receive special
     treatment,	a setting will set the value of	a loader(8) environment	vari-
     able.  The	settings that receive special treatment	are listed below.
     Settings beginning	with "*" below define the modules to be	loaded and may
     have any prefix; the prefix identifies a module.  All such	settings shar-
     ing a common prefix refer to the same module.

		   Delay in seconds before automatically booting.  A user with
		   console access will be able to interrupt the	autoboot
		   process and escape into the interactive mode	by pressing a
		   key on the console during this delay.

		   If set to "NO", no autoboot is automatically	attempted af-
		   ter processing /boot/loader.rc, though explicit autoboot's
		   are processed normally, using a 10 second delay.

		   If set to "0", no delay is inserted,	but any	keys pressed
		   while the kernel and	modules	are loaded will	enter interac-
		   tive	mode.

		   If set to "-1", no delay will be inserted and loader.conf
		   starts interactive mode only	if autoboot has	failed.	 In
		   combination with the	beastie_disable	option,	this option
		   prevents users with console access from being able to in-
		   terrupt the autoboot	process	and escape to the loader
		   prompt.  To use the autoboot_delay option in	this manner,
		   beastie_disable must	be set to "YES".

     exec	   Immediately executes	a loader(8) command.  This type	of
		   setting cannot be processed by programs other than
		   loader(8), so its use should	be avoided.  Multiple in-
		   stances of it will be processed independently.

		   Space separated list	of directories to process for configu-
		   ration files.  The lua-based	loader will process files with
		   a ".conf" suffix that are placed in these directories.

		   Defines additional configuration files to be	processed
		   right after the present file.  loader_conf_files should be
		   treated as write-only.  One cannot depend on	any value re-
		   maining in the loader environment or	carried	over into the
		   kernel environment.

     kernel	   Name	of the kernel to be loaded.  If	no kernel name is set,
		   no additional modules will be loaded.  The name must	be a
		   subdirectory	of /boot that contains a kernel.

		   Flags to be passed to the kernel.

		   Specify the root partition to mount.	 For example:


		   loader(8) automatically calculates the value	of this	tun-
		   able	from /etc/fstab	from the partition the kernel was
		   loaded from.	 The calculated	value might be calculated in-
		   correctly when /etc/fstab is	not available during loader(8)
		   startup (as during diskless booting from NFS), or if	a dif-
		   ferent device is desired by the user.  The preferred	value
		   can be set in /loader.conf.

		   The value can also be overridden from the loader(8) command
		   line.  This is useful for system recovery when /etc/fstab
		   is damaged, lost, or	read from the wrong partition.

     password	   Protect boot	menu with a password without interrupting
		   autoboot process.  The password should be in	clear text
		   format.  If a password is set, boot menu will not appear
		   until any key is pressed during countdown period specified
		   by autoboot_delay variable or autoboot process fails.  In
		   both	cases user should provide specified password to	be
		   able	to access boot menu.

		   Provides a password to be required by check-password	before
		   execution is	allowed	to continue.  The password should be
		   in clear text format.  If a password	is set,	the user must
		   provide specified password to boot.

		   If set to "YES", module names will be displayed as they are

		   Blacklist of	modules.  Modules specified in the blacklist
		   may not be loaded automatically with	a *_load directive,
		   but they may	be loaded directly at the loader(8) prompt.
		   Blacklisted modules may still be loaded indirectly as de-
		   pendencies of other modules.

     *_load	   If set to "YES", that module	will be	loaded.	 If no name is
		   defined (see	below),	the module's name is taken to be the
		   same	as the prefix.

     *_name	   Defines the name of the module.

     *_type	   Defines the module's	type.  If none is given, it defaults
		   to a	kld module.

     *_flags	   Flags and parameters	to be passed to	the module.

     *_before	   Commands to be executed before the module is	loaded.	 Use
		   of this setting should be avoided.

     *_after	   Commands to be executed after the module is loaded.	Use of
		   this	setting	should be avoided.

     *_error	   Commands to be executed if the loading of a module fails.
		   Except for the special value	"abort", which aborts the
		   bootstrap process, use of this setting should be avoided.

     WARNING: developers should	never use these	suffixes for any kernel	envi-
     ronment variables (tunables) or conflicts will result.

     Most of loader.conf's default settings can	be ignored.  The few of	them
     which are important or useful are:

		     ("NO") If set to "YES", a bitmap will be loaded to	be
		     displayed on screen while booting.

		     ("/boot/splash.bmp") Name of the bitmap to	be loaded.
		     Any other name can	be used.

		     ("9600" or	the value of the BOOT_COMCONSOLE_SPEED vari-
		     able when loader(8) was compiled).	 Sets the speed	of the
		     serial console.  If the previous boot loader stage	speci-
		     fied that a serial	console	is in use then the default
		     speed is determined from the current serial port speed

	   console   ("vidconsole") "comconsole" selects serial	console,
		     "vidconsole" selects the video console, "efi" selects the
		     EFI console, "nullconsole"	selects	a mute console (useful
		     for systems with neither a	video console nor a serial
		     port), and	"spinconsole" selects the video	console	which
		     prevents any input	and hides all output replacing it with
		     "spinning"	character (useful for embedded products	and

		     Set font size for framebuffer mode.  Default font size is
		     selected based on screen resolution, to achieve terminal
		     dimensions	80x24.

		     Value "0" will trigger BIOS loader	to switch to use VESA
		     BIOS Extension (VBE) frame	buffer mode for	console.  The
		     same effect can be	achieved by setting

		     Value "1" will force BIOS loader to use VGA text mode.

		     If	vbe_max_resolution is not set, the loader will try to
		     set screen	resolution based on EDID information.  If EDID
		     is	not available, the default resolution is 800x600 (if



		     screen.height, screen.width, screen.depth are set by
		     loader when loader	is using framebuffer mode to draw the


		     Specify the maximum desired resolution for	the EFI	or VBE
		     framebuffer console.  The following values	are accepted:

		     Value	     Resolution
		     480p	     640x480
		     720p	     1280x720
		     1080p	     1920x1080
		     2160p	     3840x2160
		     4k		     3840x2160
		     5k		     5120x2880
		     WidthxHeight    WidthxHeight

	   kernel    ("kernel")

	   kernels   ("kernel kernel.old") Space or comma separated list of
		     kernels to	present	in the boot menu.

		     ("/boot/loader.conf /boot/loader.conf.local")


		     ("NO") If set to "YES", will load the splash screen mod-
		     ule, making it possible to	display	a bmp image on the
		     screen while booting.

		     ("NO") If set to "YES", will load the splash screen mod-
		     ule, making it possible to	display	a pcx image on the
		     screen while booting.

		     ("NO") If set to "YES", the vesa module will be loaded,
		     enabling bitmaps above VGA	resolution to be displayed.

		     If	set to "YES", the beastie boot menu will be skipped.

	   loader_logo ("orbbw")
		     Selects a desired logo in the beastie boot	menu.  Possi-
		     ble values	are: "orbbw", "orb", "fbsdbw", "beastiebw",
		     "beastie",	and "none".

		     If	set to "NO", the beastie boot menu will	be displayed
		     without ANSI coloring.

		     ("YES") If	set to "NO", the very early boot-time entropy
		     file will not be loaded.  See the entropy entries in

		     ("/boot/entropy") The name	of the very early boot-time
		     entropy cache file.

		     ("NO") If set to "YES", the microcode update file speci-
		     fied by cpu_microcode_name	will be	loaded and applied
		     very early	during boot.  This provides functionality sim-
		     ilar to cpucontrol(8) but ensures that CPU	features en-
		     abled by microcode	updates	can be used by the kernel.
		     The update	will be	re-applied automatically when resuming
		     from an ACPI sleep	state.	If the update file contains
		     updates for multiple processor models, the	kernel will
		     search for	and extract a matching update.	Currently this
		     setting is	supported only on Intel	i386 and amd64 proces-
		     sors.  It has no effect on	other processor	types.

		     A path to a microcode update file.

     Other settings that may be	used in	loader.conf that have no default

		     Specifies a comma-delimited list of FDT overlays to ap-
		     ply.  /boot/dtb/overlays is created by default for	over-
		     lays to be	placed in.

		     If	set to "YES", attempt to auto-detect kernels installed
		     in	/boot.	This is	an option specific to the Lua-based
		     loader.  It is not	available in the default Forth-based

     /boot/defaults/loader.conf	 default settings -- do	not change this	file.
     /boot/loader.conf		 user defined settings.
     /boot/loader.conf.local	 machine-specific settings for sites with a
				 common	loader.conf.

     rc.conf(5), boot(8), cpucontrol(8), loader(8), loader.4th(8)

     The file loader.conf first	appeared in FreeBSD 3.2.

     This manual page was written by Daniel C. Sobral <>.

     The loader(8) stops reading loader.conf when it encounters	a syntax er-
     ror, so any options which are vital for booting a particular system
     (i.e., "hw.ata.ata_dma=0")	should precede any experimental	additions to

FreeBSD	13.0			 July 31, 2021			  FreeBSD 13.0


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