Manual Pages  — LOADER.CONF

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

Though Ns 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 controls.

The general parsing rules are:

• Spaces and empty lines are ignored.
• A # sign will mark the remainder of the line as a comment.
• Only one setting can be present on each line.

All settings have the following format:

    variable="value"

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 variable. 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 sharing a common prefix refer to the same module.

autoboot_delay
	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 after 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 interactive 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 interrupt 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 instances of it will be processed independently.
loader_conf_dirs
	Space separated list of directories to process for configuration files. The lua-based loader will process files with a ".conf" suffix that are placed in these directories.
loader_conf_files
	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 remaining 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.
kernel_options
	Flags to be passed to the kernel.
vfs.root.mountfrom
	Specify the root partition to mount. For example:     vfs.root.mountfrom="ufs:/dev/da0s1a" loader(8) automatically calculates the value of this tunable from /etc/fstab from the partition the kernel was loaded from. The calculated value might be calculated incorrectly when /etc/fstab is not available during loader(8) startup (as during diskless booting from NFS), or if a different 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.
bootlock_password
	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.
verbose_loading
	If set to "YES", module names will be displayed as they are loaded.
module_blacklist
	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 dependencies 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 environment variables (tunables) or conflicts will result.

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

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