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BOOT.CFG(5)		    BSD	File Formats Manual		   BOOT.CFG(5)

     boot.cfg -- configuration file for	/boot

     The file /boot.cfg	is used	to alter the behaviour of the standard boot
     loader described in boot(8).  Configuration changes include setting the
     timeout, choosing a console device, altering the banner text and display-
     ing a menu	allowing boot commands to be easily chosen.  If	a boot.cfg
     file is not present, the system will boot as normal.

     The format	of the file is a series	of lines containing keyword/value
     pairs separated by	an equals sign (`=').  There should be no whitespace
     surrounding the equals sign.  Lines beginning with	a hash (`#') are com-
     ments and will be ignored.

     Some keywords can be present multiple times in the	file to	define addi-
     tional items.  Such keywords are noted below.

     banner   (may be present multiple times) The text from banner lines is
	      displayed	instead	of the standard	welcome	text by	the boot
	      loader.  Up to 10	lines can be defined.  No special character
	      sequences	are recognised,	so to specify a	blank line, a banner
	      line with	no value should	be given.

     clear    If nonzero, clear	the screen before printing the banner.	If
	      zero, do not clear the screen (the default).

     consdev  Changes the console device to that specified in the value.
	      Valid values are any of those that could be specified at the
	      normal boot prompt with the consdev command.

     default  Used to specify the default menu item  which will	be chosen in
	      the case of Return being pressed or the timeout timer reaching
	      zero.  The value is the number of	the menu item as displayed.
	      As described above, the menu items are counted from 1 in the or-
	      der listed in boot.cfg.  If not specified, the default value
	      will be option 1,	i.e. the first item.

     format   Changes how the menu options are displayed.  Should be set to
	      one of `a' for automatic,	`l' for	letters	and `n'	for numbers.
	      If set to	automatic (the default), menu options will be dis-
	      played numerically unless	there are more than 9 options and the
	      timeout is greater than zero.  If	there are more than 9 options
	      with a timeout greater than zero and the format is set to	num-
	      ber, only	the first 9 options will be available.

     load     Used to load kernel modules, which will be passed	on to the ker-
	      nel for initialization during early boot.	 The argument is ei-
	      ther the complete	path and file name of the module to be loaded,
	      or a symbolic module name.  When the argument is not an absolute
	      path, the	boot loader will first attempt to load
	      If that file does	not exist, it will then	attempt	to load
	      /_name_.	May be used as many times as needed.

     menu     (may be present multiple times) Used to define a menu item to be
	      displayed	to the end-user	at boot	time which allows a series of
	      boot commands to be run without further typing.  The value con-
	      sists of the required menu text, followed	by a colon (`:') and
	      then the desired command(s).  Multiple commands can be specified
	      separated	by a semi-colon.  If the specified menu	text is	empty
	      (the colon appears immediately after the equals sign), then the
	      displayed	menu text is the same as the command.  For example:

	      menu=Boot	normally:boot
	      menu=Boot	single-user:boot -s
	      menu=Boot	with module foo:load /foo.kmod;boot
	      menu=Boot	with serial console:consdev com0;boot
	      menu=:boot hd1a:netbsd -as

	      Each menu	item will be prefixed by an ascending number when dis-
	      played, i.e. the order in	the boot.cfg file is important.

	      Each command is executed just as though the user had typed it in
	      and so can be any	valid command that would be accepted at	the
	      normal boot prompt.  In addition,	"prompt" can be	used to	drop
	      to the normal boot prompt.

     timeout  If the value is greater than zero, this specifies	the time in
	      seconds that the boot loader will	wait for the end-user to
	      choose a menu item.  During the countdown	period,	they may press
	      Return to	choose the default option or press a number key	corre-
	      sponding to a menu option.  If any other key is pressed, the
	      countdown	will stop and the user will be prompted	to choose a
	      menu option with no further time limit.  If the timeout value is
	      set to zero, the default option will be booted immediately.  If
	      the timeout value	is negative or is not a	number,	there will be
	      no time limit for	the user to choose an option.

	      Passes a userconf(4) command to the kernel at boot time .

     rndseed  Takes the	path to	a random-seed file as written by the -S	flag
	      to rndctl(8) as an argument.  This file is used to seed the ker-
	      nel entropy pool rnd(9) very early in kernel startup, so that
	      high quality randomness is available to all kernel modules.
	      This argument should be supplied before any "load" commands that
	      may load executable modules.

     Here is an	example	boot.cfg file:

	   banner=Welcome to NetBSD
	   banner=Please choose	an option from the following menu:
	   menu=Boot normally:boot
	   menu=Boot single-user:boot -s
	   menu=Boot from second disk:boot hd1a:
	   menu=Boot with module foo:load /foo.kmod;boot
	   menu=Boot with modules foo and bar:load /foo.kmod;load /bar.kmod;boot
	   menu=Boot Xen with 256MB for	dom0:load /netbsd-XEN3_DOM0 console=pc;multiboot /usr/pkg/xen3-kernel/xen.gz dom0_mem=256M
	   menu=Boot Xen with 256MB for	dom0 (serial):load /netbsd-XEN3_DOM0 console=com0;multiboot /usr/pkg/xen3-kernel/xen.gz	dom0_mem=256M console=com1 com1=115200,8n1
	   menu=Boot Xen with dom0 in single-user mode:load /netbsd-XEN3_DOM0 -s;multiboot /usr/pkg/xen3-kernel/xen.gz dom0_mem=256M
	   menu=Go to command line (advanced users only):prompt
	   userconf disable ehci*
	   # Always load ramdisk module

     N.B. Xen counts serial ports from com1 upwards, but NetBSD	counts from
     com0, so the appropriate device name must be used.	 Please	see the	Xen
     with serial console example above.

     This will clear the screen	and display:

	   Welcome to NetBSD

	   Please choose an option from	the following menu:

		 1. Boot normally
		 2. Boot single-user
		 3. Boot from second disk
		 4. Boot with module foo
		 5. Boot with modules foo and bar
		 6. Boot Xen with 256 MB for dom0
		 7. Boot Xen with 256 MB for dom0 (serial)
		 8. Boot Xen with dom0 in single-user mode
		 9. Go to command line (advanced users only)

	   Option [1]:

     It	will then wait for the user to type 1, 2, 3, 4,	5, 6, 7, 8 or 9	fol-
     lowed by Return.  Pressing	Return by itself will run option 1.  There
     will be no	timeout.

     boot(8), boothowto(9)

     The boot.cfg file appeared	in NetBSD 5.0.

     The boot.cfg extensions to	boot(8)	were written by	Stephen	Borrill

     Support for boot.cfg is currently for NetBSD/i386 and NetBSD/amd64	only.
     It	is hoped that its use will be extended to other	appropriate ports that
     use the boot(8) interface.

BSD			       November	28, 2011			   BSD


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