BLESS(8)						    BSD System Manager's Manual 						  BLESS(8)

NAME

     bless -- set volume bootability and startup disk options

SYNOPSIS

     bless --help

     bless --folder directory [--file file] [--bootinfo [file]] [--bootefi [file]] [--label name | --labelfile file] [--setBoot]
	   [--openfolder directory] [--nextonly] [--shortform] [--legacy] [--legacydrivehint device] [--options string] [--quiet | --verbose]

     bless --mount directory [--file file] [--setBoot] [--nextonly] [--shortform] [--legacy] [--legacydrivehint device] [--options string]
	   [--quiet | --verbose]

     bless --device device [--label name | --labelfile file] [--startupfile file] [--setBoot] [--nextonly] [--shortform] [--legacy]
	   [--legacydrivehint device] [--options string] [--quiet | --verbose]

     bless --netboot --server url [--nextonly] [--options string] [--quiet | --verbose]

     bless --info [directory] [--getBoot] [--plist] [--quiet | --verbose] [--version]

     bless --unbless directory

DESCRIPTION

     bless is used to modify the volume bootability characteristics of filesystems, as well as select the active boot volume.  bless has 6 modes
     of execution: Folder Mode, Mount Mode, Device Mode, NetBoot Mode, Info Mode, and Unbless Mode.

     Folder Mode allows you to select a directory on a mounted volume to act as the ``blessed'' directory, which causes the system firmware to
     look in that directory for boot code. EFI-based systems also support a ``blessed'' system file, which is the primary mechanism of specifying
     the booter for a volume for those systems. In Folder Mode, if you are operating on an HFS+ volume, the HFS+ Volume Header is updated to
     reflect the files/directories given, which persists even if the volume is moved to another system or NVRAM is cleared.

     Mount Mode does not make permanent modifications to the filesystem, but rather set the system firmware to boot from the specified volume,
     assuming it has been properly blessed. This is a subset of the functionality of Folder Mode with the --setBoot option, but is convenient when
     you don't want to change or interrogate the filesystem for its blessed status.

     Device Mode is similar to Mount Mode, but allows selection of unmounted filesystems, for instance while in single user mode. It can also per-
     form certain offline modifications to the filesystem, but is not generally recommended.

     NetBoot Mode sets the system firmware to boot from the network, using a URL syntax to specify the protocol and server.  bless only sets the
     local system to go into NetBoot mode, and does not communicate to the server what image should be used, if there are multiple images. Some
     other mechanism, such as using Startup Disk, should be used to select that.

     Info Mode will print out the currently-blessed directory of a volume, or if no mountpoint is specified, the active boot volume that the
     firmware is set to boot from.

     Unbless Mode complements Folder Mode, and clears the persistent blessed folder and file information on HFS+ volumes.

     Additionally, --help can be used to display the command-line usage summary.

   FILE/FOLDER MODE
     Folder Mode has the following options:
     --folder directory       Set this directory to be the Mac OS X/Darwin blessed directory, containing a BootX secondary loader for New World
			      machines.
     --file file	      Set this file to be the Mac OS X/Darwin blessed boot file, containing a booter for EFI-based systems. If this option
			      is not provided, a default boot file is used based on the blessed directory.
     --bootinfo [file]	      Create a BootX file in the Mac OS X/Darwin system folder using file as a source. If file is not provided, a default
			      is used (see FILES), using a path relative to the mountpoint you are blessing. This attempts to ensure that a BootX
			      is used that is compatible with the OS on the target volume.
     --bootefi [file]	      Create a boot.efi file in the Mac OS X/Darwin system folder using file as a source. If file is not provided, a
			      default is used (see FILES), using a path relative to the mountpoint you are blessing. This attempts to ensure that
			      a boot.efi is used that is compatible with the OS on the target volume. If --file is also provided, the new file
			      will be created at that path instead.
     --label name	      Render a text label used in the firmware-based OS picker
     --labelfile file	      Use a pre-rendered label used for the firmware-based OS picker
     --openfolder directory   Specify a folder to be opened in the Finder when the volume is mounted by the system.
     --setBoot		      Set the system to boot off the specified partition. This is implemented in a platform-specific manner. On Open
			      Firmware-based systems, the boot-device variable is modified. On EFI-based systems, the efi-boot-device variable is
			      changed.
     --nextonly 	      Only change the boot device selection for the next boot. This is only supported on EFI-based systems.
     --shortform	      Use an abbreviated device path form. This option can allow for booting from new devices, at the expense of boot time
			      performance. This is only supported on EFI-based systems.
     --legacy		      If --setBoot is given, set the firmware to boot a legacy BIOS-based operating system from the specified disk. The
			      active flag of an MBR-partitioned disk is not modified, which can be done with fdisk(8) . This is only supported on
			      EFI-based systems.
     --legacydrivehint device
			      Instruct the firmware to treat the specified whole disk as the primary, master IDE drive. This is only supported on
			      EFI-based systems.
     --options		      Set load options associated with the new boot option. This is only supported on EFI-based systems, and in general
			      should be avoided. Instead, use nvram(8) to set "boot-args" , which will work with both Open Firmware- and EFI-based
			      systems.
     --quiet		      Do not print any output
     --verbose		      Print verbose output

   MOUNT MODE
     Mount Mode has the following options:
     --mount directory	      Use the volume mounted at directory to change the active boot volume, in conjunction with --setBoot . The volume
			      must already be properly blessed.
     --file file	      Instead of allowing the firmware to discover the booter based on the blessed directory or file, pass an explicit
			      path to the firmware to boot from. This can be used to run EFI applications or EFI booters for alternate OSes, but
			      should not be normally used. This is only supported on EFI-based systems.
     --setBoot		      Same as for Folder Mode.
     --nextonly 	      Same as for Folder Mode.
     --shortform	      Same as for Folder Mode.
     --legacy		      Same as for Folder Mode.
     --legacydrivehint device
			      Same as for Folder Mode.
     --options		      Same as for Folder Mode.
     --quiet		      Do not print any output
     --verbose		      Print verbose output

   DEVICE MODE
     Device Mode has the following options:
     --device device	      Use the block device device to change the active boot volume. No volumes should be mounted from device , and the
			      filesystem should already be properly blessed.
     --label name	      Set the firmware-based OS picker label for the unmounted filesystem, using name , which should be in UTF-8 encoding.
     --labelfile file	      Use a pre-rendered label used with the firmware-based OS picker.
     --setBoot		      Set the system to boot off the specified partition, as with Folder and Mount Modes.
     --startupfile file       Add the file as the HFS+ StartupFile, and update other information on disk as appropriate for the startup file type.
     --nextonly 	      Same as for Folder Mode.
     --shortform	      Same as for Folder Mode.
     --options		      Same as for Folder Mode.
     --legacy		      Same as for Folder Mode.
     --legacydrivehint device
			      Same as for Folder Mode.
     --quiet		      Do not print any output
     --verbose		      Print verbose output

   NETBOOT MODE
     NetBoot Mode has the following options:
     --netboot		      Instead of setting the active boot selection to a disk-based volume, set the system to NetBoot.
     --server protocol://[interface@]server
			      A URL specification of how to boot the system. Currently, the only protocol supported is BSDP ("bsdp"), Apple's Boot
			      Service Discovery Protocol. The interface is optional, and the server is the IPv4 address of the server in dotted-
			      quad notation. If there is not a specific server you'd like to use, pass "255.255.255.255" to have the firmware
			      broadcast for the first available server. Examples of this notation would be "bsdp://255.255.255.255" and
			      "bsdp://en1@17.203.12.203".
     --nextonly 	      Same as for Folder Mode.
     --options		      Same as for Folder Mode.
     --quiet		      Do not print any output
     --verbose		      Print verbose output

   INFO MODE
     Info Mode has the following options:
     --info [directory]       Print out the blessed system folder for the volume mounted at directory . If directory is not specified, print
			      information for the currently selected boot volume (which may not necessarily be '/' .
     --getBoot		      Print out the logical boot volume, based on what is currently selected. This option will take into account the fact
			      that the firmware may be pointing to an auxiliary booter partition, and will print out the corresponding root parti-
			      tion for those cases. If the system is configured to NetBoot, a URL matching the format of the --server specifica-
			      tion for NetBoot mode will be printed.
     --plist		      Output all information in Property List (.plist) format, suitable for parsing by CoreFoundation. This is most useful
			      when bless is executed from another program and its standard output must be parsed.
     --quiet		      Do not print any output
     --verbose		      Print verbose output
     --version		      Print bless version and exit immediately

   UNBLESS MODE
     Unbless Mode has the following options:
     --unbless directory      Use the HFS+ volume mounted at directory and unset any persistent blessed files/directories in the HFS+ Volume
			      Header.

FILES

     /usr/standalone/ppc/bootx.bootinfo  Secondary loader with XML headers, used with the --bootinfo flag. Used for booting New World PPC-based
					 Macintoshes. If the argument to --bootinfo is ommitted, this file will be used as the default input.
     /usr/standalone/i386/boot.efi	 Booter for EFI-based systems, used with the --bootefi flag. If the argument to --bootefi is ommitted,
					 this file will be used as the default input.
     /System/Library/CoreServices	 Typical blessed folder for Mac OS X and Darwin

EXAMPLES

   FOLDER MODE
     To bless a volume with only Mac OS X or Darwin, and create the BootX and boot.efi files as needed:

	   bless --folder "/Volumes/Mac OS X/System/Library/CoreServices" --bootinfo --bootefi

   MOUNT MODE
     To set a volume containing either Mac OS 9 and Mac OS X to be the active volume:

	   bless --mount "/Volumes/Mac OS" --setBoot

   NETBOOT MODE
     To set the system to NetBoot and broadcast for an available server:

	   bless --netboot --server bsdp://255.255.255.255

   INFO MODE
     To gather information about the currently selected volume (as determined by the firmware), suitable for piping to a program capable of pars-
     ing Property Lists:

	   bless --info --plist

SEE ALSO

     mount(8), newfs(8), nvram(8)

Mac OS X							   May 24, 2013 							  Mac OS X