xref: /freebsd/stand/defaults/loader.conf.5 (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1.\" Copyright (c) 1999 Daniel C. Sobral
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24.Dd February 2, 2024
25.Dt LOADER.CONF 5
26.Os
27.Sh NAME
28.Nm loader.conf
29.Nd "system bootstrap configuration information"
30.Sh DESCRIPTION
31The file
32.Nm
33contains descriptive information on bootstrapping the system.
34Through
35it you can specify the kernel to be booted, parameters to be passed to
36it, and additional modules to be loaded; and generally set all variables
37described in
38.Xr loader 8 .
39.Sh SYNTAX
40Though
41.Nm Ns 's
42format was defined explicitly to resemble
43.Xr rc.conf 5 ,
44and can be sourced by
45.Xr sh 1 ,
46some settings are treated in a special fashion.
47Also, the
48behavior of some settings is defined by the setting's suffix;
49the prefix identifies which module the setting controls.
50.Pp
51The general parsing rules are:
52.Bl -bullet
53.It
54Spaces and empty lines are ignored.
55.It
56A # sign will mark the remainder of the line as a comment.
57.It
58Only one setting can be present on each line.
59.El
60.Pp
61All settings have the following format:
62.Pp
63.Dl variable="value"
64.Pp
65Unless it belongs to one of the classes of settings that receive special
66treatment, a setting will set the value of a
67.Xr loader 8
68environment variable.
69The settings that receive special
70treatment are listed below.
71Settings beginning with
72.Qq *
73below define the modules to be loaded and
74may have any prefix; the prefix identifies a module.
75All such settings sharing a common
76prefix refer to the same module.
77.Bl -tag -width Ar
78.It Ar autoboot_delay
79Delay in seconds before automatically booting.
80A user with console access will be able to interrupt the
81.Ic autoboot
82process and escape into the interactive mode by pressing a key on
83the console during this delay.
84.Pp
85If set to
86.Dq Li NO ,
87no
88.Ic autoboot
89is automatically attempted after processing
90.Pa /boot/loader.rc ,
91though explicit
92.Ic autoboot Ns 's
93are processed normally, using a 10 second delay.
94.Pp
95If set to
96.Dq Li 0 ,
97no delay is inserted, but any keys pressed while the kernel and modules are
98loaded will enter interactive mode.
99.Pp
100If set to
101.Dq Li -1 ,
102no delay will be inserted and
103.Nm
104starts interactive mode only if
105.Ic autoboot
106has failed.
107In combination with the
108.Va beastie_disable
109option, this option prevents users with console access from being able
110to interrupt the
111.Ic autoboot
112process and escape to the loader prompt.
113To use the
114.Va autoboot_delay
115option in this manner,
116.Va beastie_disable
117must be set to
118.Dq Li YES .
119.It Ar exec
120Immediately executes a
121.Xr loader 8
122command.
123This type of setting cannot be processed by programs other
124than
125.Xr loader 8 ,
126so its use should be avoided.
127Multiple instances of it will be processed
128independently.
129.It Ar loader_conf_dirs
130Space separated list of directories to process for configuration files.
131The lua-based loader will process files with a
132.Dq .conf
133suffix that are placed in these directories.
134Files found here are processed after the ones listed in
135.Va loader_conf_files
136but before the ones found in
137.Va local_loader_conf_files .
138.It Ar loader_conf_files
139Defines additional configuration files to be processed right after the
140present file.
141.Ar loader_conf_files
142should be treated as write-only.
143One cannot depend on any value remaining in the loader environment or carried
144over into the kernel environment.
145.It Ar local_loader_conf_files
146Space separated list of additional configuration files to be processed at last,
147i.e., after
148.Va loader_conf_files
149and
150.Va loader_conf_dirs
151are processed.
152.It Ar product_vars
153When set, must be a space separated list of environment variable names to walk
154through to guess product information.
155The order matters as reading a config file override the previously defined
156values.
157Undefined variables are silently ignored.
158.Pp
159When product information can be guessed, for each product information found,
160append
161.Pa /boot/loader.conf.d/PRODUCT
162to
163.Ar loader_conf_dirs .
164It can be typically used as follow:
165.Bd -literal
166smbios.system.planar.maker="PLANAR_MAKER"
167smbios.system.planar.product="PLANAR_PRODUCT"
168smbios.system.product="PRODUCT"
169uboot.m_product="M_PRODUCT"
170product_vars="smbios.system.planar.maker smbios.system.planar.product smbios.system.product uboot.m_product"
171.Ed
172.Pp
173to read files found in the following directories, in that order:
174.Bl -bullet -compact
175.It
176.Pa /boot/loader.conf.d/PLANAR_MAKER
177.It
178.Pa /boot/loader.conf.d/PLANAR_PRODUCT
179.It
180.Pa /boot/loader.conf.d/PRODUCT
181.It
182.Pa /boot/loader.conf.d/M_PRODUCT
183.El
184.It Ar kernel
185Name of the kernel to be loaded.
186If no kernel name is set, no additional
187modules will be loaded.
188The name must be a subdirectory of
189.Pa /boot
190that contains a kernel.
191.It Ar kernel_options
192Flags to be passed to the kernel.
193.It Ar vfs.root.mountfrom
194Specify the root partition to mount.
195For example:
196.Pp
197.Dl vfs.root.mountfrom="ufs:/dev/da0s1a"
198.Pp
199.Xr loader 8
200automatically calculates the value of this tunable from
201.Pa /etc/fstab
202from the partition the kernel was loaded from.
203The calculated value might be calculated incorrectly when
204.Pa /etc/fstab
205is not available during
206.Xr loader 8
207startup (as during diskless booting from NFS), or if a different
208device is desired by the user.
209The preferred value can be set in
210.Pa /loader.conf .
211.Pp
212The value can also be overridden from the
213.Xr loader 8
214command line.
215This is useful for system recovery when
216.Pa /etc/fstab
217is damaged, lost, or read from the wrong partition.
218.It Ar password
219Protect boot menu with a password without interrupting
220.Ic autoboot
221process.
222The password should be in clear text format.
223If a password is set, boot menu will not appear until any key is pressed during
224countdown period specified by
225.Va autoboot_delay
226variable or
227.Ic autoboot
228process fails.
229In both cases user should provide specified password to be able to access boot
230menu.
231.It Ar bootlock_password
232Provides a password to be required by check-password before execution is
233allowed to continue.
234The password should be in clear text format.
235If a password is set, the user must provide specified password to boot.
236.It Ar verbose_loading
237If set to
238.Dq YES ,
239module names will be displayed as they are loaded.
240.It Ar module_blacklist
241Blacklist of modules.
242Modules specified in the blacklist may not be loaded automatically with a
243.Ar *_load
244directive, but they may be loaded directly at the
245.Xr loader 8
246prompt.
247Blacklisted modules may still be loaded indirectly as dependencies of other
248modules.
249.It Ar *_load
250If set to
251.Dq YES ,
252that module will be loaded.
253If no name is defined (see below), the
254module's name is taken to be the same as the prefix.
255.It Ar *_name
256Defines the name of the module.
257.It Ar *_type
258Defines the module's type.
259If none is given, it defaults to a kld module.
260.It Ar *_flags
261Flags and parameters to be passed to the module.
262.It Ar *_before
263Commands to be executed before the module is loaded.
264Use of this setting
265should be avoided.
266.It Ar *_after
267Commands to be executed after the module is loaded.
268Use of this setting
269should be avoided.
270.It Ar *_error
271Commands to be executed if the loading of a module fails.
272Except for the
273special value
274.Dq abort ,
275which aborts the bootstrap process, use of this setting should be avoided.
276.El
277.Pp
278.Em WARNING :
279developers should never use these suffixes for any kernel environment
280variables (tunables) or conflicts will result.
281.Sh DEFAULT SETTINGS
282Most of
283.Nm Ns 's
284default settings can be ignored.
285The few of them which are important
286or useful are:
287.Bl -tag -width bootfile -offset indent
288.It Va local_loader_conf_files
289.Pq Dq /boot/loader.conf.local
290Ensure
291.Va loader.conf.local
292can always be used to override settings from files found in
293.Va loader_conf_files
294and
295.Va loader_conf_dirs .
296.It Va bitmap_load
297.Pq Dq NO
298If set to
299.Dq YES ,
300a bitmap will be loaded to be displayed on screen while booting.
301.It Va bitmap_name
302.Pq Dq Pa /boot/splash.bmp
303Name of the bitmap to be loaded.
304Any other name can be used.
305.It Va comconsole_speed
306.Dq ( 115200
307or the value of the
308.Va BOOT_COMCONSOLE_SPEED
309variable when
310.Xr loader 8
311was compiled).
312Sets the speed of the serial console.
313If the previous boot loader stage specified that a serial console
314is in use then the default speed is determined from the current
315serial port speed setting.
316.It Va console
317.Pq Dq vidconsole
318.Dq comconsole
319selects serial console,
320.Dq vidconsole
321selects the video console,
322.Dq efi
323selects the EFI console,
324.Dq nullconsole
325selects a mute console
326(useful for systems with neither a video console nor a serial port), and
327.Dq spinconsole
328selects the video console which prevents any input and hides all output
329replacing it with
330.Dq spinning
331character (useful for embedded products and such).
332.It Va screen.font
333Set font size for framebuffer mode.
334Default font size is selected based on screen resolution, to achieve
335terminal dimensions 80x24.
336.It Va screen.textmode
337Value
338.Dq 0
339will trigger BIOS loader to switch to use VESA BIOS Extension (VBE)
340frame buffer mode for console.
341The same effect can be achieved by setting
342.Va vbe_max_resolution .
343.Pp
344Value
345.Dq 1
346will force BIOS loader to use VGA text mode.
347.Pp
348If
349.Va vbe_max_resolution
350is not set, the loader will try to set screen resolution based on EDID
351information.
352If EDID is not available, the default resolution is 800x600 (if available).
353.It Va screen.height
354.It Va screen.width
355.It Va screen.depth
356.Va screen.height ,
357.Va screen.width ,
358.Va screen.depth
359are set by loader when loader is using framebuffer mode to draw the screen.
360.It Va efi_max_resolution
361.It Va vbe_max_resolution
362Specify the maximum desired resolution for the EFI or VBE framebuffer console.
363The following values are accepted:
364.Bl -column "WidthxHeight"
365.It Sy Value Ta Sy Resolution
366.It 480p Ta 640x480
367.It 720p Ta 1280x720
368.It 1080p Ta 1920x1080
369.It 1440p Ta 2560x1440
370.It 2160p Ta 3840x2160
371.It 4k Ta 3840x2160
372.It 5k Ta 5120x2880
373.It Va Width Ns x Ns Va Height Ta Va Width Ns x Ns Va Height
374.El
375.It Va kernel
376.Pq Dq kernel
377.It Va kernels
378.Pq Dq kernel kernel.old
379Space or comma separated list of kernels to present in the boot menu.
380.It Va loader_conf_files
381.Pq Dq Pa /boot/loader.conf /boot/loader.conf.local
382.It Va loader_conf_dirs
383.Pq Dq Pa /boot/loader.conf.d
384.It Va splash_bmp_load
385.Pq Dq NO
386If set to
387.Dq YES ,
388will load the splash screen module, making it possible to display a bmp image
389on the screen while booting.
390.It Va splash_pcx_load
391.Pq Dq NO
392If set to
393.Dq YES ,
394will load the splash screen module, making it possible to display a pcx image
395on the screen while booting.
396.It Va vesa_load
397.Pq Dq NO
398If set to
399.Dq YES ,
400the vesa module will be loaded, enabling bitmaps above VGA resolution to
401be displayed.
402.It Va beastie_disable
403If set to
404.Dq YES ,
405the beastie boot menu will be skipped.
406.It Va loader_logo Pq Dq Li orbbw
407Selects a desired logo in the beastie boot menu.
408Possible values are:
409.Dq Li orbbw ,
410.Dq Li orb ,
411.Dq Li fbsdbw ,
412.Dq Li beastiebw ,
413.Dq Li beastie ,
414and
415.Dq Li none .
416.It Va loader_color
417If set to
418.Dq NO ,
419the beastie boot menu will be displayed without ANSI coloring.
420.It Va entropy_cache_load
421.Pq Dq YES
422If set to
423.Dq NO ,
424the very early
425boot-time entropy file
426will not be loaded.
427See the entropy entries in
428.Xr rc.conf 5 .
429.It Va entropy_cache_name
430.Pq Dq /boot/entropy
431The name of the very early
432boot-time entropy cache file.
433.It Va cpu_microcode_load
434.Pq Dq NO
435If set to
436.Dq YES ,
437the microcode update file specified by
438.Va cpu_microcode_name
439will be loaded and applied very early during boot.
440This provides functionality similar to
441.Xr cpucontrol 8
442but ensures that CPU features enabled by microcode updates can be
443used by the kernel.
444The update will be re-applied automatically when resuming from an
445ACPI sleep state.
446If the update file contains updates for multiple processor models,
447the kernel will search for and extract a matching update.
448Currently this setting is supported only on Intel
449.Dv i386
450and
451.Dv amd64
452processors.
453It has no effect on other processor types.
454.It Va cpu_microcode_name
455A path to a microcode update file.
456.El
457.Sh OTHER SETTINGS
458Other settings that may be used in
459.Nm
460that have no default value:
461.Bl -tag -width bootfile -offset indent
462.It Va fdt_overlays
463Specifies a comma-delimited list of FDT overlays to apply.
464.Pa /boot/dtb/overlays
465is created by default for overlays to be placed in.
466.It Va kernels_autodetect
467If set to
468.Dq YES ,
469attempt to auto-detect kernels installed in
470.Pa /boot .
471This is an option specific to the Lua-based loader.
472It is not available in the default Forth-based loader.
473.El
474.Sh FILES
475.Bl -tag -width /boot/defaults/loader.conf -compact
476.It Pa /boot/defaults/loader.conf
477Default settings \(em do not change this file.
478.It Pa /boot/loader.conf
479User defined settings.
480.It Pa /boot/loader.conf.lua
481User defined settings written in lua.
482.It Pa /boot/loader.conf.d/*.conf
483User defined settings split in separate files.
484.It Pa /boot/loader.conf.d/*.lua
485User defined settings written in lua and split in separate files.
486.It Pa /boot/loader.conf.local
487Machine-specific settings for sites with a common loader.conf. Allow to override
488settings defined in other files.
489.El
490.Sh SEE ALSO
491.Xr kenv 1 ,
492.Xr loader.conf.lua 5 ,
493.Xr rc.conf 5 ,
494.Xr boot 8 ,
495.Xr cpucontrol 8 ,
496.Xr loader 8 ,
497.Xr loader.4th 8
498.Sh HISTORY
499The file
500.Nm
501first appeared in
502.Fx 3.2 .
503.Sh AUTHORS
504This manual page was written by
505.An Daniel C. Sobral Aq dcs@FreeBSD.org .
506.Sh BUGS
507The
508.Xr loader 8
509stops reading
510.Nm
511when it encounters a syntax error, so any options which are vital for
512booting a particular system (i.e.,
513.Dq Va hw.ata.ata_dma Ns "=0" )
514should precede any experimental additions to
515.Nm .
516