xref: /freebsd/stand/defaults/loader.conf.5 (revision 42249ef2)
1.\" Copyright (c) 1999 Daniel C. Sobral
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25.\" $FreeBSD$
26.Dd October 6, 2018
27.Dt LOADER.CONF 5
28.Os
29.Sh NAME
30.Nm loader.conf
31.Nd "system bootstrap configuration information"
32.Sh DESCRIPTION
33The file
34.Nm
35contains descriptive information on bootstrapping the system.
36Through
37it you can specify the kernel to be booted, parameters to be passed to
38it, and additional modules to be loaded; and generally set all variables
39described in
40.Xr loader 8 .
41.Pp
42.Sh SYNTAX
43Though
44.Nm Ns 's
45format was defined explicitly to resemble
46.Xr rc.conf 5 ,
47and can be sourced by
48.Xr sh 1 ,
49some settings are treated in a special fashion.
50Also, the
51behavior of some settings is defined by the setting's suffix;
52the prefix identifies which module the setting controls.
53.Pp
54The general parsing rules are:
55.Bl -bullet
56.It
57Spaces and empty lines are ignored.
58.It
59A # sign will mark the remainder of the line as a comment.
60.It
61Only one setting can be present on each line.
62.El
63.Pp
64All settings have the following format:
65.Pp
66.Dl variable="value"
67.Pp
68Unless it belongs to one of the classes of settings that receive special
69treatment, a setting will set the value of a
70.Xr loader 8
71environment variable.
72The settings that receive special
73treatment are listed below.
74Settings beginning with
75.Qq *
76below define the modules to be loaded and
77may have any prefix; the prefix identifies a module.
78All such settings sharing a common
79prefix refer to the same module.
80.Bl -tag -width Ar
81.It Ar exec
82Immediately executes a
83.Xr loader 8
84command.
85This type of setting cannot be processed by programs other
86than
87.Xr loader 8 ,
88so its use should be avoided.
89Multiple instances of it will be processed
90independently.
91.It Ar loader_conf_files
92Defines additional configuration files to be processed right after the
93present file.
94.It Ar kernel
95Name of the kernel to be loaded.
96If no kernel name is set, no additional
97modules will be loaded.
98The name must be a subdirectory of
99.Pa /boot
100that contains a kernel.
101.It Ar kernel_options
102Flags to be passed to the kernel.
103.It Ar vfs.root.mountfrom
104Specify the root partition to mount.
105For example:
106.Pp
107.Dl vfs.root.mountfrom="ufs:/dev/da0s1a"
108.Pp
109.Xr loader 8
110automatically calculates the value of this tunable from
111.Pa /etc/fstab
112from the partition the kernel was loaded from.
113The calculated value might be calculated incorrectly when
114.Pa /etc/fstab
115is not available during
116.Xr loader 8
117startup (as during diskless booting from NFS), or if a different
118device is desired by the user.
119The preferred value can be set in
120.Pa /loader.conf .
121.Pp
122The value can also be overridden from the
123.Xr loader 8
124command line.
125This is useful for system recovery when
126.Pa /etc/fstab
127is damaged, lost, or read from the wrong partition.
128.It Ar password
129Protect boot menu with a password without interrupting
130.Ic autoboot
131process.
132The password should be in clear text format.
133If a password is set, boot menu will not appear until any key is pressed during
134countdown period specified by
135.Va autoboot_delay
136variable or
137.Ic autoboot
138process fails.
139In both cases user should provide specified password to be able to access boot
140menu.
141.It Ar bootlock_password
142Provides a password to be required by check-password before execution is
143allowed to continue.
144The password should be in clear text format.
145If a password is set, the user must provide specified password to boot.
146.It Ar verbose_loading
147If set to
148.Dq YES ,
149module names will be displayed as they are loaded.
150.It Ar module_blacklist
151Blacklist of modules.
152Modules specified in the blacklist may not be loaded automatically with a
153.Ar *_load
154directive, but they may be loaded directly at the
155.Xr loader 8
156prompt.
157Blacklisted modules may still be loaded indirectly as dependencies of other
158modules.
159.It Ar *_load
160If set to
161.Dq YES ,
162that module will be loaded.
163If no name is defined (see below), the
164module's name is taken to be the same as the prefix.
165.It Ar *_name
166Defines the name of the module.
167.It Ar *_type
168Defines the module's type.
169If none is given, it defaults to a kld module.
170.It Ar *_flags
171Flags and parameters to be passed to the module.
172.It Ar *_before
173Commands to be executed before the module is loaded.
174Use of this setting
175should be avoided.
176.It Ar *_after
177Commands to be executed after the module is loaded.
178Use of this setting
179should be avoided.
180.It Ar *_error
181Commands to be executed if the loading of a module fails.
182Except for the
183special value
184.Dq abort ,
185which aborts the bootstrap process, use of this setting should be avoided.
186.El
187.Pp
188.Em WARNING:
189developers should never use these suffixes for any kernel environment
190variables (tunables) or conflicts will result.
191.Sh DEFAULT SETTINGS
192Most of
193.Nm Ns 's
194default settings can be ignored.
195The few of them which are important
196or useful are:
197.Bl -tag -width bootfile -offset indent
198.It Va bitmap_load
199.Pq Dq NO
200If set to
201.Dq YES ,
202a bitmap will be loaded to be displayed on screen while booting.
203.It Va bitmap_name
204.Pq Dq Pa /boot/splash.bmp
205Name of the bitmap to be loaded.
206Any other name can be used.
207.It Va comconsole_speed
208.Dq ( 9600
209or the value of the
210.Va BOOT_COMCONSOLE_SPEED
211variable when
212.Xr loader 8
213was compiled).
214Sets the speed of the serial console.
215If the previous boot loader stage specified that a serial console
216is in use then the default speed is determined from the current
217serial port speed setting.
218.It Va console
219.Pq Dq vidconsole
220.Dq comconsole
221selects serial console,
222.Dq vidconsole
223selects the video console,
224.Dq nullconsole
225selects a mute console
226(useful for systems with neither a video console nor a serial port), and
227.Dq spinconsole
228selects the video console which prevents any input and hides all output
229replacing it with
230.Dq spinning
231character (useful for embedded products and such).
232.It Va efi_max_resolution
233Specify the maximum desired resolution for the EFI console.
234The following values are accepted:
235.Bl -column "WidthxHeight"
236.It Sy Value Ta Sy Resolution
237.It 480p Ta 640x480
238.It 720p Ta 1280x720
239.It 1080p Ta 1920x1080
240.It 2160p Ta 3840x2160
241.It 4k Ta 3840x2160
242.It 5k Ta 5120x2880
243.It Va Width Ns x Ns Va Height Ta Va Width Ns x Ns Va Height
244.El
245.It Va kernel
246.Pq Dq kernel
247.It Va kernels
248.Pq Dq kernel kernel.old
249Space or comma separated list of kernels to present in the boot menu.
250.It Va loader_conf_files
251.Pq Dq Pa /boot/loader.conf /boot/loader.conf.local
252.It Va splash_bmp_load
253.Pq Dq NO
254If set to
255.Dq YES ,
256will load the splash screen module, making it possible to display a bmp image
257on the screen while booting.
258.It Va splash_pcx_load
259.Pq Dq NO
260If set to
261.Dq YES ,
262will load the splash screen module, making it possible to display a pcx image
263on the screen while booting.
264.It Va vesa_load
265.Pq Dq NO
266If set to
267.Dq YES ,
268the vesa module will be loaded, enabling bitmaps above VGA resolution to
269be displayed.
270.It Va beastie_disable
271If set to
272.Dq YES ,
273the beastie boot menu will be skipped.
274.It Va loader_logo Pq Dq Li orbbw
275Selects a desired logo in the beastie boot menu.
276Possible values are:
277.Dq Li orbbw ,
278.Dq Li orb ,
279.Dq Li fbsdbw ,
280.Dq Li beastiebw ,
281.Dq Li beastie ,
282and
283.Dq Li none .
284.It Va loader_color
285If set to
286.Dq NO ,
287the beastie boot menu will be displayed without ANSI coloring.
288.It Va entropy_cache_load
289.Pq Dq YES
290If set to
291.Dq NO ,
292the very early
293boot-time entropy file
294will not be loaded.
295See the entropy entries in
296.Xr rc.conf 5 .
297.It Va entropy_cache_name
298.Pq Dq /boot/entropy
299The name of the very early
300boot-time entropy cache file.
301.It Va cpu_microcode_load
302.Pq Dq NO
303If set to
304.Dq YES ,
305the microcode update file specified by
306.Va cpu_microcode_name
307will be loaded and applied very early during boot.
308This provides functionality similar to
309.Xr cpucontrol 8
310but ensures that CPU features enabled by microcode updates can be
311used by the kernel.
312The update will be re-applied automatically when resuming from an
313ACPI sleep state.
314If the update file contains updates for multiple processor models,
315the kernel will search for and extract a matching update.
316Currently this setting is supported only on Intel
317.Dv i386
318and
319.Dv amd64
320processors.
321It has no effect on other processor types.
322.It Va cpu_microcode_name
323A path to a microcode update file.
324.El
325.Sh OTHER SETTINGS
326Other settings that may be used in
327.Nm
328that have no default value:
329.Bl -tag -width bootfile -offset indent
330.It Va fdt_overlays
331Specifies a comma-delimited list of FDT overlays to apply.
332.Pa /boot/dtb/overlays
333is created by default for overlays to be placed in.
334.It Va kernels_autodetect
335If set to
336.Dq YES ,
337attempt to auto-detect kernels installed in
338.Pa /boot .
339This is an option specific to the Lua-based loader.
340It is not available in the default Forth-based loader.
341.El
342.Sh FILES
343.Bl -tag -width /boot/defaults/loader.conf -compact
344.It Pa /boot/defaults/loader.conf
345default settings -- do not change this file.
346.It Pa /boot/loader.conf
347user defined settings.
348.It Pa /boot/loader.conf.local
349machine-specific settings for sites with a common loader.conf.
350.El
351.Sh SEE ALSO
352.Xr rc.conf 5 ,
353.Xr boot 8 ,
354.Xr cpucontrol 8 ,
355.Xr loader 8 ,
356.Xr loader.4th 8
357.Sh HISTORY
358The file
359.Nm
360first appeared in
361.Fx 3.2 .
362.Sh AUTHORS
363This manual page was written by
364.An Daniel C. Sobral Aq dcs@FreeBSD.org .
365.Sh BUGS
366The
367.Xr loader 8
368stops reading
369.Nm
370when it encounters a syntax error, so any options which are vital for
371booting a particular system (i.e.\&
372.Dq Va hw.ata.ata_dma Ns "=0" )
373should precede any experimental additions to
374.Nm .
375