LOADER.CONF(5) File Formats and Configurations LOADER.CONF(5)

loader.confsystem bootstrap configuration information


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(7).

Loader implements set of builtin commands and functions and script interpreter as standalone binary program. When starting, the loader will read the file /boot/loader.rc as initialization and startup script, to include other support files and to read the configuration, describing current boot environment. All loader scripts and configuration files are located in the /boot directory tree.

The file /boot/loader.rc must contain the following two lines for loader.conf to be automatically processed:

include /boot/forth/loader.4th

The default /boot/loader.rc is provided by the operating system and may be replaced on operating system update. The local updates are advised to be added into the /boot/loader.rc.local

The configuration variables are read from the following files:

Managed by the eeprom(8) command.
Loader defaults provided by the operating system.
System specific loader configuration. May be provided by the operating system.
User editable loader configuration.
User editable loader configuration snippets. The files are processed in lexicographical order. The configuration snippets mechanism is not available in case of TFTP boot as TFTP does not provide the directory list.
Configuration file for transient boot. This file is created by the reboot(8) command and is automatically removed when system is reaching the multi-user run level.

The configuration is processed in the order listed above.

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:


Unless it belongs to one of the classes of settings that receive special treatment, a setting will set the value of a loader(7) 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.

Immediately executes a loader(7) command. This type of setting cannot be processed by programs other than loader(7), so its use should be avoided. Multiple instances of it will be processed independently.
Defines additional configuration files to be processed right after the present file.
Name of the kernel to be loaded. If no kernel name is set, no additional modules will be loaded.
Flags to be passed to the kernel.
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 loaded.
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.
Defines the name of the module.
Defines the module's type. If none is given, it defaults to a kld module.
Flags and parameters to be passed to the module.
Commands to be executed before the module is loaded. Use of this setting should be avoided.
Commands to be executed after the module is loaded. Use of this setting should be avoided.
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.

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

(“text”) “ttya” - “ttyd” selects serial console, “text” selects the video 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 such).
(“i86pc/kernel/${ISADIR}”) /platform sub-directory containing kernel
(“/boot/loader.conf /boot/loader.conf.local”)
If set to “YES”, the beastie boot menu will be skipped. The beastie boot menu is always skipped if running non-x86 hardware.
Selects a desired logo in the beastie boot menu. Possible values depend on distribution; “none” will disable the logo.
If set to “NO”, the beastie boot menu will be displayed without ANSI coloring.

loader(7), loader.4th(7), boot(8), eeprom(8)

The loader(7) stops reading loader.conf when it encounters a syntax error, so any options which are vital for booting a particular system should precede any experimental additions to loader.conf.

November 26, 2017 OmniOS