1 ################################################################################
2 # Thelp DDisplay command help
4 help [topic [subtopic]]
8 The help command displays help on commands and their usage.
10 In command help, a term enclosed with <...> indicates a value as
11 described by the term. A term enclosed with [...] is optional,
12 and may not be required by all forms of the command.
14 Some commands may not be available in `help'. Use the `?' command
15 to list most available commands.
17 To boot another kernel than the default in kernel/, change directory
18 to the kernel directory, and execute `loadall' and `boot' commands.
19 E.g. to do a verbose boot of kernel in kernel.XXX/:
26 If needed, disable the ACPI driver with:
29 set hint.acpi.0.disabled=1
31 If needed, disable the AHCI driver with:
34 set hint.ahci.0.disabled=1
36 If needed, disable the EHCI driver with:
39 set hint.ehci.0.disabled=1
41 For more information on ACPI, AHCI and EHCI use `help' on these topics.
43 ################################################################################
44 # T<variable>=<value> DAssign value to variable
48 Assign value to variable. The value is always assigned to local
49 variable <variable>. If <variable> is in the list of known kernel
50 environment variables or is a kernel tunable, the value is also
51 assigned to the kernel environment variable of the given name.
52 Local variables are unset if <value> is empty. Kernel environment
53 variables may have empty values.
55 Two kinds of variables are maintained by this program (loader(8)):
56 local variables, that is for loader(8) use only, and kernel
57 environment variables, that kernel will have access to when it starts.
58 The assignment described above, will assign to a local variable and, if
59 it is applicable, also snoop assignment to kernel environment variable.
61 ################################################################################
62 # TAHCI DControl AHCI module behaviour
66 The AHCI driver provides support for SATA controllers conforming to
67 the Advanced Host Controller Interface specification.
69 The NATA driver provides support for some AHCI controllers, the AHCI
70 driver is used if both NATA and AHCI drivers provides support for a
71 controller. If AHCI driver is disabled, NATA driver will be used.
73 If the ahci_load variable is set, the AHCI module will be loaded.
74 The AHCI driver can be disabled with:
77 set hint.ahci.0.disabled=1
79 A link speed of 1.5Gb/s can be enforced with:
81 set hint.ahci.force150=1
83 To refrain from attempting to send some higher level ATA commands
84 which some devices might not properly implement use:
86 set hint.ahci.nofeatures=1
88 See ahci.4 man page (on booted system) for full description.
90 ################################################################################
91 # Tautoboot DBoot after a delay
93 autoboot [<delay> [<prompt>]]
95 Displays <prompt> or a default prompt, and counts down <delay> seconds
96 before attempting to boot. If <delay> is not specified, the default
97 value is $autoboot_delay.
99 ################################################################################
100 # Tboot DBoot immediately
102 boot [-<flag> ...] [<kernelname>]
104 Boot the system. If flags are specified, they are added to the
105 arguments for the kernel. If <kernelname> is specified, and a kernel
106 has not already been loaded, it will be booted instead of the default
107 kernel. <flag> values include:
108 -a Same as `set boot_askname'
109 -C Same as `set boot_cdrom'
110 -c Same as `set boot_userconfig'
111 -d Same as `set boot_ddb'
112 -g Same as `set boot_gdb'
113 -h Same as `set boot_serial'
114 -m Mute the system console
115 -p Pause after each attached device during device probing phase
116 -r Use statically configured device for root file system
117 -s Same as `set boot_single'
118 -V Same as `set boot_vidcons'
119 -v Same as `set boot_verbose'
121 <flag>s can also be set via kernel_options variable.
122 See also boot.8 man page (on booted system) for <flag> values.
124 ################################################################################
125 # Techo DEcho arguments
127 echo [-n] [<message>]
129 Emits <message>, with no trailing newline if -n is specified. This is
130 most useful in conjunction with scripts and the '@' line prefix.
132 Variables are substituted by prefixing them with $, e.g.
134 echo Current device is $currdev
136 will print the current device.
138 ################################################################################
139 # TEHCI DControl EHCI module behaviour
143 The EHCI driver provides support for the USB Enhanched Host Controller
144 Interface, which is used by USB 2.0 controllers.
146 If the ehci_load variable is set, the EHCI module will be loaded.
147 The EHCI driver can be disabled with:
150 set hint.ehci.0.disabled=1
152 See ehci.4 man page (on booted system) for full description.
154 ################################################################################
155 # Tload DLoad a kernel or module
157 load [-t <type>] <file> [<argument> ...]
159 Loads the module contained in <file> into memory. If no other modules
160 are loaded, <file> must be a kernel or the command will fail.
162 If -t is specified, the module is loaded as raw data of <type>, for
163 later use by the kernel or other modules. <type> may be any string.
165 Any arguments passed after the name of the file to be loaded will be
166 passed as arguments to that file.
168 ################################################################################
173 Displays a listing of files in the directory <path>, or the root
174 directory of the current device if <path> is not specified.
176 The -l argument displays file sizes as well; the process of obtaining
177 file sizes on some media may be very slow.
179 ################################################################################
180 # Tlsdev DList all devices
184 List all devices. Disk slices and partitions from which it may be
185 possible to load modules are marked with '*'.
186 If -v is specified, print more details, like size and position of
187 disk slices and partitions.
189 ################################################################################
190 # Tlsmod DList modules
194 List loaded modules. If -v is specified, print more details.
196 ################################################################################
201 Show contents of text files. When displaying the contents of more,
202 than one file, if the user elects to quit displaying a file, the
203 remaining files will not be shown.
205 ################################################################################
206 # Tpnpscan DScan for PnP devices
210 Scan for Plug-and-Play devices. This command is normally automatically
211 run as part of the boot process, in order to dynamically load modules
212 required for system operation.
214 If the -v argument is specified, details on the devices found will
217 ################################################################################
218 # Tset DSet a kernel environment variable
221 set <env_variable>=<value>
223 The set command is used to set kernel environment variables.
225 See also `<variable>=<value>' command for distinction on local and
226 kernel environment variables.
228 ################################################################################
229 # Tset Sautoboot_delay DSet the default autoboot / menu delay
231 set autoboot_delay=<value>
233 Sets the default delay in seconds for the `autoboot' and `menu'
234 commands to wait before booting. The default value is 10 seconds.
236 ################################################################################
237 # Tset Sbootfile DSet the default boot file set
239 set bootfile=<file>[;<file>...]
241 Sets the default set of kernel boot filename(s). It may be overridden
242 by setting the bootfile variable to a semicolon-separated list of
243 filenames, each of which will be searched for in the $module_path
244 directories. The default value is "kernel".
246 ################################################################################
247 # Tset Sboot_askname DPrompt for root device
251 Instructs the kernel to prompt the user for the name of the root device
252 when the kernel is booted.
254 ################################################################################
255 # Tset Sboot_cdrom DBoot from CDROM
259 Instructs the kernel to boot from CDROM when the kernel is booted.
261 ################################################################################
262 # Tset Sboot_ddb DDrop to the kernel debugger (DDB)
266 Instructs the kernel to start in the DDB debugger, rather than
267 proceeding to initialise when booted.
269 ################################################################################
270 # Tset Sboot_gdb DSelect gdb-remote mode
274 Selects gdb-remote mode for the kernel debugger by default.
276 ################################################################################
277 # Tset Sboot_single DStart system in single-user mode
281 Prevents the kernel from initiating a multi-user startup, single-user
282 mode will be entered when the kernel has finished device probes.
284 ################################################################################
285 # Tset Sboot_serial DUse serial console after boot
289 Use serial console after boot. See also `set console' command.
291 ################################################################################
292 # Tset Sboot_verbose DVerbose boot messages
296 Setting this variable causes extra debugging information to be printed
297 by the kernel especially during the boot phase.
299 ################################################################################
300 # Tset Sboot_vidcons DUse video console after boot
304 Use video console after boot. See also `set console' command.
306 ################################################################################
307 # Tset Skernel_options DKernel options
311 Set kernel boot flags. E.g.:
313 set kernel_options="-v -a"
315 See also boot command; kernel_options sets default <flags>.
317 ################################################################################
318 # Tset Sconsole DSet the current console
320 set console[=<value>]
322 Sets the current console. <value> include `vidconsole', `comconsole'
323 and `nullconsole'. If <value> is omitted, a list of valid consoles
326 ################################################################################
327 # Tset Sdefault_kernel DSet default kernel directory
329 set default_kernel=<path>
331 Selects the default kernel directory for `menu' command. Default value
334 ################################################################################
335 # Tset Scurrdev DSet the current device
339 Selects the default device. See `lsdev' for available devices.
341 ################################################################################
342 # Tset Sinit_path DSet the list of init candidates
344 set init_path=<path>[:<path>...]
346 Sets the list of binaries which the kernel will try to run as initial
350 ################################################################################
351 # Tset Smodule_path DSet the module search path
353 set module_path=<path>[;<path>...]
355 Sets the list of directories which will be searched in for modules
356 named in a load command or implicitly required by a dependency. An
357 empty <path> specifies the current directory. The default value is
360 ################################################################################
361 # Tset Sprompt DSet the command prompt
365 The command prompt is displayed when the loader is waiting for input.
366 Variable substitution is performed on the prompt. The default value
369 ################################################################################
370 # Tset Srootdev DSet the root filesystem
374 By default the value of $currdev is used to set the root filesystem
375 when the kernel is booted. This can be overridden by setting
378 ################################################################################
379 # Tset Stunables DSet kernel tunable values
381 Various kernel tunable parameters can be overridden by specifying new
382 values in the environment.
384 set hw.pci.allow_unsupported_io_range=<value>
386 Allow the PCI Bridge to pass through an unsupported
387 memory range assigned by the BIOS.
389 value is 0 (default) or non-zero to enable.
391 set hw.pci.enable_io_modes=<value>
393 Enable PCI resources which are left off by some BIOSes
394 or are not enabled correctly by the device driver.
396 value is 1 (default), but this may cause problems with
397 some peripherals. Set to 0 to disable.
399 set hw.physmem=<value> MAXMEM
401 Limits the amount of physical memory space available to
402 the system to <value> bytes. <value> may have a `k', `M' or
403 `G' suffix to indicate kilobytes, megabytes and gigabytes
404 respectively. Note that the current i386 architecture
405 limits this value to 4GB.
407 On systems where memory cannot be accurately probed,
408 this option provides a hint as to the actual size of
409 system memory (which will be tested before use).
411 set hw.syscons.sc_no_suspend_vtswitch=<value>
413 Disable VT switching on suspend.
415 value is 0 (default) or non-zero to enable.
417 set kern.emergence_intr_enable=<value>
419 Setting this to 1 enables emergency interrupt polling. All
420 interrupt handlers are executed periodically. This mode is
421 very expensive and should only be used to get a system
422 accessible when interrupt routing is otherwise broken. It
423 is primarily used by kernel developers to debug new systems.
425 set kern.emergence_intr_freq=<value>
427 Set the polling rate for the emergency interrupt polling
428 code. The default is 10 (hz) to dissuade causual use. If
429 you are doing real work with emergency interrupt polling
430 mode enabled, it is recommended that you use a frequency
431 between 100hz and 300hz.
433 set kern.ipc.nmbclusters=<value> NMBCLUSTERS
435 Set the number of mbuf clusters to be allocated. The value
436 cannot be set below the default determined when the kernel
439 set kern.vm.kmem.size=<value>
441 Sets the size of kernel memory (bytes). This overrides
442 the value determined when the kernel was compiled.
444 set machdep.disable_mtrrs=1
446 Disable the use of i686 MTRRs (i386 only)
448 set net.inet.tcp.tcbhashsize=<value> TCBHASHSIZE
450 Overrides the compile-time set value of TCBHASHSIZE or
451 the preset default of 512. Must be a power of 2.
453 set vfs.root.mountfrom=<value>
455 Specify root file system. <value> is a semicolon separated
456 list of file systems. File system format is file system type
457 and disk store, separated by colon. This variable needs to be
458 set when using boot-only partition, which is typically mounted
459 on root file system as /boot.
461 One file system example:
464 One file system HAMMER multi volume examples:
467 Several file systems, boot list, example:
468 ufs:da0s1a;hammer:ad1s1d
470 Each file system in the list will be tried in the order
471 specified until the mount succeeds. If all fail, the
472 `mountroot>' prompt is displayed for manual entry.
474 You may not specify devtab labels here but you can specify
475 paths available to devfs such as:
476 hammer:serno/L41JYE0G.s1d
478 ################################################################################
479 # Tshow DShow values of kernel environment variable
481 show [<env_variable>]
483 Displays the value of <env_variable>, or all kernel environment
484 variables if not specified.
486 See also `<variable>=<value>' command for distinction on local and
487 kernel environment variables.
489 ################################################################################
490 # Tinclude DExecute script file
494 The entire contents of <file> are read into memory before executing
495 commands, so it is safe to source a file from removable media.
497 ################################################################################
498 # Toptinclude DExecute script file; ignore exit status
500 optinclude <file> ...
502 The entire contents of <file> are read into memory before executing
503 commands, so it is safe to source a file from removable media.
504 Return success and execute all commands even if some commands fail.
506 ################################################################################
507 # Tcd DChange directory
511 Change working directory to <directory>. Default is $base.
513 ################################################################################
514 # Toptcd DChange directory; ignore exit status
518 Change working directory to <directory>. Default is $base.
519 Return success even if changing directory fails.
521 ################################################################################
522 # Tpwd DPrint working directory
526 Show working directory.
528 ################################################################################
529 # Tlocal DList local variables
531 local [<local_variable> ...]
533 Display the value of given local variables, or all variables if not
536 See also `<variable>=<value>' command for distinction on local and
537 kernel environment variables.
539 ################################################################################
540 # Tlunset DUnset local variable
542 lunset <local_variable>
544 Unset local variable: discard value and remove variable.
546 See also `<variable>=<value>' command for distinction on local and
547 kernel environment variables.
549 ################################################################################
550 # Tlunsetif DUnset local variables if envvar true
552 lunsetif <local_variable> <env_variable>
554 Unset <local_variable> if <env_variable> is true, i.e. set to 1 or YES.
556 See also `<variable>=<value>' command for distinction on local and
557 kernel environment variables.
559 ################################################################################
560 # Tloadall DLoad kernel + modules
564 Load kernel and all modules specified by MODULE_load variables.
566 ################################################################################
567 # Tifexists DConditional file/dir present
571 Conditional <path> exists, i.e. file/dir present.
573 ################################################################################
574 # Tifset DConditional kenv variable present
578 Conditional <env_variable> exists.
580 ################################################################################
581 # Telseifexists DConditional file/dir present
585 Conditional <path> exists, i.e. file/dir present.
587 ################################################################################
588 # Telse DConditional if/else/endif
592 Conditional if/else/endif.
594 ################################################################################
595 # Tendif DConditional if/else/endif
599 Conditional if/else/endif.
601 ################################################################################
602 # Tmenuclear DClear all menus
606 Clear all menu bullets.
608 ################################################################################
609 # Tmenuitem DAdd menu bullet
611 menuitem <key> <description text>
613 Start new menu bullet, when running menu system bullet is choosen by
614 pressing <key>. E.g.:
616 menuitem a "Boot Backup kernel kernel.alt"
618 ################################################################################
619 # Tmenuadd DAdd script line for menu bullet
621 menuadd <command line>
623 Add script line for current menu bullet. E.g.:
625 menuadd lunsetif acpi_load hint.acpi.0.disabled
627 ################################################################################
628 # Tmenu DRun menu system
634 ################################################################################
635 # Tread DRead input from the terminal
637 read [-t <value>] [-p <prompt>] [<env_variable>]
639 The read command reads a line of input from the terminal. If the
640 -t argument is specified, it will return nothing if no input has been
641 received after <value> seconds. (Any keypress will cancel the
644 If -p is specified, <prompt> is printed before reading input. No
645 newline is emitted after the prompt.
647 If a variable name is supplied, the variable is set to the value read,
648 less any terminating newline.
650 ################################################################################
651 # Tunload DRemove all modules from memory
655 This command removes any kernel and all loaded modules from memory.
657 ################################################################################
658 # Tunset DUnset a kernel environment variable
662 If allowed, the named kernel environment variable's value is discarded
663 and the variable is removed.
665 See also `<variable>=<value>' command for distinction on local and
666 kernel environment variables.
668 ################################################################################