boot - Improve lsdev (2)
[dragonfly.git] / sys / boot / common / loader.8
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1.\" Copyright (c) 1999 Daniel C. Sobral
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\" notice, this list of conditions and the following disclaimer in the
11.\" documentation and/or other materials provided with the distribution.
12.\"
13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23.\" SUCH DAMAGE.
24.\"
5ee58eed 25.\" $FreeBSD: src/sys/boot/common/loader.8,v 1.57 2003/06/29 20:57:55 brueffer Exp $
746342c5 26.\" $DragonFly: src/sys/boot/common/loader.8,v 1.24 2008/09/15 21:23:44 thomas Exp $
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27.\"
28.\" Note: The date here should be updated whenever a non-trivial
29.\" change is made to the manual page.
b27d3d3b 30.Dd October 20, 2009
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31.Dt LOADER 8
32.Os
33.Sh NAME
34.Nm loader
35.Nd kernel bootstrapping final stage
36.Sh DESCRIPTION
37The program called
38.Nm
39is the final stage of
9bb2a92d 40.Dx Ns 's
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41kernel bootstrapping process.
42On IA32 (i386) architectures, it is a
43.Pa BTX
44client.
45It is linked statically to
46.Xr libstand 3
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47and located in the
48.Pa /boot
49or
50.Pa /
51directory.
52.Pp
53If a
54.Pa /boot
55directory exist on the boot file system, then
56.Dq /boot/
57is prepended to all relative file names used by
58.Nm .
59This makes it possible to locate all files used by
60.Nm
61in either
62.Pa /
63or
64.Pa /boot
65directory on the boot file system.
66If boot and root are the same file systems, then files used by
67.Nm
68are located in
984263bc 69.Pa /boot .
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70If boot and root are different file systems, then files used by
71.Nm
72are located in
73.Pa /
74on the boot file system, which is mounted as
75.Pa /boot
76on the root file system when the kernel is running.
984263bc 77.Pp
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78.Nm
79provides a scripting language that can be used to
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80automate tasks, do pre-configuration or assist in recovery
81procedures.
82This scripting language is roughly divided in
83two main components.
84The smaller one is a set of commands
85designed for direct use by the casual user, called "builtin
86commands" for historical reasons.
87The main drive behind these commands is user-friendliness.
88The bigger component is an
89.Tn ANS
5ee58eed 90Forth compatible Forth interpreter based on FICL, by
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91.An John Sadler .
92.Pp
93During initialization,
94.Nm
95will probe for a console and set the
96.Va console
97variable, or set it to serial console
98.Pq Dq comconsole
99if the previous boot stage used that.
100Then, devices are probed,
101.Va currdev
102and
103.Va loaddev
104are set, and
105.Va LINES
106is set to 24.
107Next,
108.Tn FICL
109is initialized, the builtin words are added to its vocabulary, and
2a2fb130 110.Pa boot.4th
5ee58eed 111is processed if it exists.
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112No disk switching is possible while that file is being read.
113The inner interpreter
114.Nm
115will use with
116.Tn FICL
117is then set to
118.Ic interpret ,
119which is
120.Tn FICL Ns 's
121default.
122After that,
2a2fb130 123.Pa loader.rc
984263bc 124is processed if available, and, failing that,
2a2fb130 125.Pa boot.conf
5ee58eed 126is read for historical reasons.
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127These files are processed through the
128.Ic include
129command, which reads all of them into memory before processing them,
130making disk changes possible.
131.Pp
132At this point, if an
133.Ic autoboot
134has not been tried, and if
135.Va autoboot_delay
136is not set to
137.Dq NO
138(not case sensitive), then an
139.Ic autoboot
140will be tried.
141If the system gets past this point,
142.Va prompt
143will be set and
144.Nm
145will engage interactive mode.
146.Sh BUILTIN COMMANDS
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147In
148.Nm ,
149builtin commands take parameters from the command line.
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150Presently,
151the only way to call them from a script is by using
152.Pa evaluate
153on a string.
154If an error condition occurs, an exception will be generated,
155which can be intercepted using
156.Tn ANS
157Forth exception handling
158words.
159If not intercepted, an error message will be displayed and
160the interpreter's state will be reset, emptying the stack and restoring
161interpreting mode.
162.Pp
163The builtin commands available are:
164.Pp
165.Bl -tag -width Ds -compact
166.It Ic autoboot Op Ar seconds
167Proceeds to bootstrap the system after a number of seconds, if not
168interrupted by the user.
169Displays a countdown prompt
170warning the user the system is about to be booted,
171unless interrupted by a key press.
172The kernel will be loaded first if necessary.
173Defaults to 10 seconds.
174.Pp
175.It Ic bcachestat
176Displays statistics about disk cache usage.
177For depuration only.
178.Pp
179.It Ic boot
180.It Ic boot Ar kernelname Op Cm ...
181.It Ic boot Fl flag Cm ...
182Immediately proceeds to bootstrap the system, loading the kernel
183if necessary.
184Any flags or arguments are passed to the kernel, but they
185must precede the kernel name, if a kernel name is provided.
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186Flags are described in
187.Xr boot 8 .
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188.Pp
189.Em WARNING :
190The behavior of this builtin is changed if
191.Xr loader.4th 8
192is loaded.
193.Pp
194.It Ic echo Xo
195.Op Fl n
196.Op Aq message
197.Xc
198Displays text on the screen.
199A new line will be printed unless
200.Fl n
201is specified.
202.Pp
203.It Ic heap
204Displays memory usage statistics.
205For debugging purposes only.
206.Pp
207.It Ic help Op topic Op subtopic
208Shows help messages read from
2a2fb130 209.Pa loader.help .
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210The special topic
211.Em index
212will list the topics available.
213.Pp
214.It Ic include Ar file Op Ar
215Process script files.
216Each file, in turn, is completely read into memory,
217and then each of its lines is passed to the command line interpreter.
218If any error is returned by the interpreter, the include
219command aborts immediately, without reading any other files, and
220returns an error itself (see
221.Sx ERRORS ) .
222.Pp
223.It Ic load Xo
224.Op Fl t Ar type
225.Ar file Cm ...
226.Xc
227Loads a kernel, kernel loadable module (kld), or file of opaque
228contents tagged as being of the type
229.Ar type .
230Kernel and modules can be either in a.out or ELF format.
231Any arguments passed after the name of the file to be loaded
232will be passed as arguments to that file.
233Currently, argument passing does not work for the kernel.
234.Pp
235.It Ic ls Xo
236.Op Fl l
237.Op Ar path
238.Xc
239Displays a listing of files in the directory
240.Ar path ,
241or the root directory if
242.Ar path
243is not specified.
244If
245.Fl l
246is specified, file sizes will be shown too.
247.Pp
248.It Ic lsdev Op Fl v
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249Lists all devices with known file systems, where a
250'*' prefix indicates a device from which it may be
251possible to load modules.
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252If
253.Fl v
254is specified, more details are printed.
255.Pp
256.It Ic lsmod Op Fl v
257Displays loaded modules.
258If
259.Fl v
260is specified, more details are shown.
261.Pp
262.It Ic more Ar file Op Ar
263Display the files specified, with a pause at each
264.Va LINES
265displayed.
266.Pp
267.It Ic pnpscan Op Fl v
268Scans for Plug-and-Play devices.
269This is not functional at present.
270.Pp
271.It Ic read Xo
272.Op Fl t Ar seconds
273.Op Fl p Ar prompt
274.Op Va variable
275.Xc
276Reads a line of input from the terminal, storing it in
277.Va variable
278if specified.
279A timeout can be specified with
280.Fl t ,
281though it will be canceled at the first key pressed.
282A prompt may also be displayed through the
283.Fl p
284flag.
285.Pp
286.It Ic reboot
287Immediately reboots the system.
288.Pp
289.It Ic set Ar variable
290.It Ic set Ar variable Ns = Ns Ar value
291Set loader's environment variables.
292.Pp
293.It Ic show Op Va variable
294Displays the specified variable's value, or all variables and their
295values if
296.Va variable
297is not specified.
298.Pp
299.It Ic unload
300Remove all modules from memory.
301.Pp
302.It Ic unset Va variable
303Removes
304.Va variable
305from the environment.
306.Pp
307.It Ic \&?
308Same as
309.Dq help index .
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310.El
311.Ss BUILTIN ENVIRONMENT VARIABLES
312The
313.Nm
314has actually two different kinds of
315.Sq environment
316variables.
317There are ANS Forth's
318.Em environmental queries ,
319and a separate space of environment variables used by builtins, which
320are not directly available to Forth words.
321It is the latter type that this section covers.
322.Pp
323Environment variables can be set and unset through the
324.Ic set
325and
326.Ic unset
327builtins, and can have their values interactively examined through the
328use of the
329.Ic show
330builtin.
331Their values can also be accessed as described in
332.Sx BUILTIN PARSER .
333.Pp
334Notice that these environment variables are not inherited by any shell
335after the system has been booted.
336.Pp
337A few variables are set automatically by
338.Nm .
339Others can affect the behavior of either
340.Nm
341or the kernel at boot.
342Some options may require a value,
343while others define behavior just by being set.
344Both types of builtin variables are described below.
345.Bl -tag -width bootfile
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346.It Va acpi_load
347Unset this to disable automatic loading of the ACPI module.
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348.It Va autoboot_delay
349Number of seconds
350.Ic autoboot
351will wait before booting.
352If this variable is not defined,
353.Ic autoboot
354will default to 10 seconds.
355.Pp
356If set to
357.Dq NO ,
358no
359.Ic autoboot
360will be automatically attempted after processing
2a2fb130 361.Pa loader.rc ,
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362though explicit
363.Ic autoboot Ns 's
364will be processed normally, defaulting to 10 seconds delay.
365.It Va boot_askname
366Instructs the kernel to prompt the user for the name of the root device
367when the kernel is booted.
368.It Va boot_ddb
369Instructs the kernel to start in the DDB debugger, rather than
370proceeding to initialize when booted.
371.It Va boot_gdb
372Selects gdb-remote mode for the kernel debugger by default.
373.It Va boot_single
374Prevents the kernel from initiating a multi-user startup; instead single-user
375mode will be entered when the kernel has finished device probing.
376.It Va boot_userconfig
377Requests that the kernel's interactive device configuration program
378be run when the kernel is booted.
379.It Va boot_verbose
380Setting this variable causes extra debugging information to be printed
381by the kernel during the boot phase.
382.It Va bootfile
383List of semicolon-separated search path for bootable kernels.
384The default is
385.Dq Li kernel;kernel.old .
386.It Va console
387Defines the current console.
388.It Va currdev
389Selects the default device.
390Syntax for devices is odd.
391.It Va init_path
392Sets the list of binaries which the kernel will try to run as the initial
393process.
394The first matching binary is used.
395The default list is
22628b14 396.Dq Li /sbin/init:/sbin/oinit:/sbin/init.bak .
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397.It Va interpret
398Has the value
bc65ccee 399.Dq Li OK
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400if the Forth's current state is interpreting.
401.It Va LINES
402Define the number of lines on the screen, to be used by the pager.
403.It Va module_path
404Sets the list of directories which will be searched for modules
405named in a load command or implicitly required by a dependency.
406The default value for this variable is
f4e821f3 407.Dq Li /boot;/boot/modules;/;/modules .
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408.It Va num_ide_disks
409Sets the number of IDE disks as a workaround for some problems in
410finding the root disk at boot.
411This has been deprecated in favor of
412.Va root_disk_unit .
413.It Va prompt
414Value of
415.Nm Ns 's
416prompt.
417Defaults to
bc65ccee 418.Dq Li "\e${interpret}" .
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419.It Va root_disk_unit
420If the code which detects the disk unit number for the root disk is
421confused, e.g. by a mix of SCSI and IDE disks, or IDE disks with
422gaps in the sequence (e.g. no primary slave), the unit number can
423be forced by setting this variable.
424.It Va rootdev
425By default the value of
426.Va currdev
5ee58eed 427is used to set the root file system
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428when the kernel is booted.
429This can be overridden by setting
430.Va rootdev
431explicitly.
432.It Va dumpdev
433The name of a device where the kernel can save a crash dump in case
434of a panic.
435This automatically sets the
436.Va kern.dumpdev
437.Xr sysctl 3
438MIB variable.
439.El
440.Pp
441Other variables are used to override kernel tunable parameters.
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442The following
443.Nm
444tunables are available:
984263bc 445.Bl -tag -width Va
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446.It Va hw.irq.X.dest
447Set irqX's destination to the given CPUID,
448which starts from 0.
449If the specified value is larger than the last CPUID,
450then the first CPUID will be used.
451This variable should not be used if IO/APIC support is not compiled
452into kernel.
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453.It Va hw.physmem
454Limit the amount of physical memory the system will use.
455By default the size is in bytes, but the
456.Cm k , K , m , M , g
457and
458.Cm G
459suffixes
460are also accepted and indicate kilobytes, megabytes and gigabytes
461respectively.
462An invalid suffix will result in the variable being ignored by the
463kernel.
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464.It Va hw.usb.hack_defer_exploration
465The USB keyboard will sometimes not attach properly unless you set this
42480ff5 466variable to 0.
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467.It Va kern.emergency_intr_enable
468Setting this to 1 enables emergency interrupt polling. All interrupt
469handlers are executed periodically. This mode is very expensive and should
470only be used to get a system accessible when interrupt routing is
3f5e28f4 471otherwise broken. It is primarily used by kernel developers to debug new
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472systems.
473.It Va kern.emergency_intr_freq
474Set the polling rate for the emergency interrupt polling code. The
475default is 10 (hz) to dissuade casual use. If you are doing real work
476with emergency interrupt polling mode enabled, it is recommended
477that you use a frequency between 100hz and 300hz.
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478.It Va kern.maxusers
479Set the size of a number of statically allocated system tables; see
480.Xr tuning 7
481for a description of how to select an appropriate value for this
482tunable.
483When set, this tunable replaces the value declared in the kernel
484compile-time configuration file.
485.It Va kern.ipc.nmbclusters
486Set the number of mbuf clusters to be allocated.
487The value cannot be set below the default
488determined when the kernel was compiled.
489Modifies
490.Va NMBCLUSTERS .
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491.It Va kern.ipc.nsfbufs
492Set the number of
493.Xr sendfile 2
494buffers to be allocated.
495Overrides
496.Dv NSFBUFS .
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497.It Va kern.mmxopt
498Toggles the mmx optimizations for the bcopy/copyin/copyout routines
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499.It Va kern.vm.kmem.size
500Sets the size of kernel memory (bytes).
5ee58eed 501This overrides the value determined when the kernel was compiled.
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502.It Va kern.maxswzone
503Limits the amount of KVM to be used to hold swap
504meta information, which directly governs the
505maximum amount of swap the system can support.
506This value is specified in bytes of KVA space
507and defaults to around 70MBytes.
508Care should be taken
509to not reduce this value such that the actual
aa0d550a 510amount of configured swap exceeds \(12 the
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511kernel-supported swap.
512The default 70MB allows
513the kernel to support a maximum of (approximately)
51414GB of configured swap.
515Only mess around with
516this parameter if you need to greatly extend the
517KVM reservation for other resources such as the
518buffer cache or
519.Va NMBCLUSTERS .
520Modifies
521.Va VM_SWZONE_SIZE_MAX .
522.It Va kern.maxbcache
523Limits the amount of KVM reserved for use by the
524buffer cache, specified in bytes.
525The default maximum is 200MB.
526This parameter is used to
527prevent the buffer cache from eating too much
528KVM in large-memory machine configurations.
529Only mess around with this parameter if you need to
530greatly extend the KVM reservation for other resources
531such as the swap zone or
532.Va NMBCLUSTERS .
533Note that
534the NBUF parameter will override this limit.
535Modifies
536.Va VM_BCACHE_SIZE_MAX .
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537.It Va machdep.disable_mtrrs
538Disable the use of i686 MTRRs (x86 only).
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539.It Va net.inet.tcp.tcbhashsize
540Overrides the compile-time set value of
541.Va TCBHASHSIZE
542or the preset default of 512.
543Must be a power of 2.
2a2fb130 544.It Va vfs.root.mountfrom
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545A semicolon separated list of partitions to try
546as the kernel root file system.
547Device format is file system type and partition,
548separated by colon.
549Used with boot-only partition, which is
550typically mounted on root file system as
746342c5 551.Pa /boot .
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552.Bl -hyphen
553.It
554One device example: "hammer:da8s1a"
555.It
556Several devices example: "ufs:da0s1a;hammer:ad1s1d"
557.El
558.Pp
559Each device in the list will be tried in the order specified
560until the mount succeeds.
561If all fail, the
562.Li mountroot>
563prompt is displayed for manual entry.
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564.Pp
565You may not specify devtab labels here but you can specify paths available
566to devfs such as "hammer:serno/L41JYE0G.s1d".
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567.El
568.Ss BUILTIN PARSER
569When a builtin command is executed, the rest of the line is taken
570by it as arguments, and it is processed by a special parser which
571is not used for regular Forth commands.
572.Pp
573This special parser applies the following rules to the parsed text:
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574.Bl -enum
575.It
576All backslash characters are preprocessed.
577.Bl -bullet
578.It
579\eb , \ef , \er , \en and \et are processed as in C.
580.It
581\es is converted to a space.
582.It
583\ev is converted to
584.Tn ASCII
58511.
586.It
587\ez is just skipped.
588Useful for things like
589.Dq \e0xf\ez\e0xf .
590.It
591\e0xN and \e0xNN are replaced by the hex N or NN.
592.It
593\eNNN is replaced by the octal NNN
594.Tn ASCII
595character.
596.It
597\e" , \e' and \e$ will escape these characters, preventing them from
598receiving special treatment in Step 2, described below.
599.It
600\e\e will be replaced with a single \e .
601.It
602In any other occurrence, backslash will just be removed.
603.El
604.It
605Every string between non-escaped quotes or double-quotes will be treated
606as a single word for the purposes of the remaining steps.
607.It
608Replace any
609.Li $VARIABLE
610or
611.Li ${VARIABLE}
612with the value of the environment variable
613.Va VARIABLE .
614.It
615Space-delimited arguments are passed to the called builtin command.
616Spaces can also be escaped through the use of \e\e .
617.El
618.Pp
619An exception to this parsing rule exists, and is described in
620.Sx BUILTINS AND FORTH .
621.Ss BUILTINS AND FORTH
622All builtin words are state-smart, immediate words.
623If interpreted, they behave exactly as described previously.
624If they are compiled, though,
625they extract their arguments from the stack instead of the command line.
626.Pp
627If compiled, the builtin words expect to find, at execution time, the
628following parameters on the stack:
629.D1 Ar addrN lenN ... addr2 len2 addr1 len1 N
630where
631.Ar addrX lenX
632are strings which will compose the command line that will be parsed
633into the builtin's arguments.
634Internally, these strings are concatenated in from 1 to N,
635with a space put between each one.
636.Pp
637If no arguments are passed, a 0
638.Em must
639be passed, even if the builtin accepts no arguments.
640.Pp
641While this behavior has benefits, it has its trade-offs.
642If the execution token of a builtin is acquired (through
643.Ic '
644or
645.Ic ['] ) ,
646and then passed to
647.Ic catch
648or
649.Ic execute ,
650the builtin behavior will depend on the system state
651.Bf Em
652at the time
653.Ic catch
654or
655.Ic execute
656is processed
657.Ef
658\&! This is particularly annoying for programs that want or need to
659handle exceptions.
660In this case, the use of a proxy is recommended.
661For example:
bc65ccee 662.Dl : (boot) boot \&;
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663.Sh FICL
664.Tn FICL
665is a Forth interpreter written in C, in the form of a forth
666virtual machine library that can be called by C functions and vice
667versa.
668.Pp
669In
670.Nm ,
671each line read interactively is then fed to
672.Tn FICL ,
673which may call
674.Nm
675back to execute the builtin words.
676The builtin
677.Ic include
678will also feed
679.Tn FICL ,
680one line at a time.
681.Pp
682The words available to
683.Tn FICL
684can be classified into four groups.
685The
686.Tn ANS
687Forth standard words, extra
688.Tn FICL
689words, extra
9bb2a92d 690.Dx
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691words, and the builtin commands;
692the latter were already described.
693The
694.Tn ANS
695Forth standard words are listed in the
696.Sx STANDARDS
697section.
698The words falling in the two other groups are described in the
699following subsections.
700.Ss FICL EXTRA WORDS
701.Bl -tag -width wid-set-super
702.It Ic .env
703.It Ic .ver
704.It Ic -roll
705.It Ic 2constant
706.It Ic >name
707.It Ic body>
708.It Ic compare
709This is the STRING word set's
710.Ic compare .
711.It Ic compile-only
712.It Ic endif
713.It Ic forget-wid
714.It Ic parse-word
715.It Ic sliteral
716This is the STRING word set's
717.Ic sliteral .
718.It Ic wid-set-super
719.It Ic w@
720.It Ic w!
721.It Ic x.
722.It Ic empty
723.It Ic cell-
724.It Ic -rot
725.El
bc65ccee 726.Ss DRAGONFLY EXTRA WORDS
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727.Bl -tag -width XXXXXXXX
728.It Ic \&$ Pq --
729Evaluates the remainder of the input buffer, after having printed it first.
730.It Ic \&% Pq --
731Evaluates the remainder of the input buffer under a
732.Ic catch
733exception guard.
734.It Ic .#
735Works like
736.Ic .
737but without outputting a trailing space.
738.It Ic fclose Pq Ar fd --
739Closes a file.
740.It Ic fkey Pq Ar fd -- char
741Reads a single character from a file.
742.It Ic fload Pq Ar fd --
743Processes a file
744.Em fd .
5ee58eed 745.It Ic fopen Pq Ar addr len mode Li -- Ar fd
984263bc 746Opens a file.
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747Returns a file descriptor, or \-1 in case of failure.
748The
749.Ar mode
750parameter selects whether the file is to be opened for read access, write
751access, or both.
752The constants
753.Dv O_RDONLY , O_WRONLY ,
754and
755.Dv O_RDWR
756are defined in
2a2fb130 757.Pa support.4th ,
5ee58eed 758indicating read only, write only, and read-write access, respectively.
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759.It Xo
760.Ic fread
761.Pq Ar fd addr len -- len'
762.Xc
763Tries to read
764.Em len
765bytes from file
766.Em fd
767into buffer
768.Em addr .
769Returns the actual number of bytes read, or -1 in case of error or end of
770file.
771.It Ic heap? Pq -- Ar cells
772Return the space remaining in the dictionary heap, in cells.
773This is not related to the heap used by dynamic memory allocation words.
774.It Ic inb Pq Ar port -- char
775Reads a byte from a port.
776.It Ic key Pq -- Ar char
777Reads a single character from the console.
778.It Ic key? Pq -- Ar flag
779Returns
780.Ic true
781if there is a character available to be read from the console.
782.It Ic ms Pq Ar u --
783Waits
784.Em u
785microseconds.
786.It Ic outb Pq Ar port char --
787Writes a byte to a port.
788.It Ic seconds Pq -- Ar u
789Returns the number of seconds since midnight.
790.It Ic tib> Pq -- Ar addr len
791Returns the remainder of the input buffer as a string on the stack.
792.It Ic trace! Pq Ar flag --
793Activates or deactivates tracing.
794Does not work with
795.Ic catch .
796.El
bc65ccee 797.Ss DRAGONFLY DEFINED ENVIRONMENTAL QUERIES
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798.Bl -tag -width Ds
799.It arch-i386
800.Ic TRUE
801if the architecture is IA32.
9bb2a92d
HP
802.It DragonFly_version
803.Dx
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804version at compile time.
805.It loader_version
806.Nm
807version.
808.El
809.Ss SYSTEM DOCUMENTATION
810.Sh FILES
811.Bl -tag -width /boot/defaults/loader.conf -compact
812.It Pa /boot/loader
813.Nm
814itself.
815.It Pa /boot/boot.4th
816Additional
817.Tn FICL
818initialization.
819.It Pa /boot/boot.conf
820.Nm
821bootstrapping script.
822Deprecated.
823.It Pa /boot/defaults/loader.conf
824.It Pa /boot/loader.conf
825.It Pa /boot/loader.conf.local
826.Nm
827configuration files, as described in
828.Xr loader.conf 5 .
829.It Pa /boot/loader.rc
830.Nm
831bootstrapping script.
832.It Pa /boot/loader.help
833Loaded by
834.Ic help .
835Contains the help messages.
836.El
837.Sh EXAMPLES
838Boot in single user mode:
839.Pp
840.Dl boot -s
841.Pp
842Load kernel's user configuration file.
843Notice that a kernel must be loaded before any other
844.Ic load
845command is attempted.
846.Bd -literal -offset indent
847load kernel
2a2fb130 848load -t userconfig_script kernel.conf
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849.Ed
850.Pp
851Load the kernel, a splash screen, and then autoboot in five seconds.
852.Bd -literal -offset indent
853load kernel
854load splash_bmp
2a2fb130 855load -t splash_image_data chuckrulez.bmp
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856autoboot 5
857.Ed
858.Pp
859Set the disk unit of the root device to 2, and then boot.
860This would be needed in a system with two IDE disks,
601c6213 861with the second IDE disk hardwired to ad2 instead of ad1.
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862.Bd -literal -offset indent
863set root_disk_unit=2
2a2fb130 864boot kernel
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865.Ed
866.Pp
867See also:
868.Bl -tag -width /usr/share/examples/bootforth/X
2a2fb130 869.It Pa loader.4th
984263bc 870Extra builtin-like words.
2a2fb130 871.It Pa support.4th
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872.Pa loader.conf
873processing words.
874.It Pa /usr/share/examples/bootforth/
875Assorted examples.
876.El
877.Sh ERRORS
878The following values are thrown by
879.Nm :
880.Bl -tag -width XXXXX -offset indent
881.It 100
882Any type of error in the processing of a builtin.
883.It -1
884.Ic Abort
885executed.
886.It -2
887.Ic Abort"
888executed.
889.It -56
890.Ic Quit
891executed.
892.It -256
893Out of interpreting text.
894.It -257
895Need more text to succeed -- will finish on next run.
896.It -258
897.Ic Bye
898executed.
899.It -259
900Unspecified error.
901.El
902.Sh SEE ALSO
903.Xr libstand 3 ,
904.Xr loader.conf 5 ,
905.Xr tuning 7 ,
906.Xr boot 8 ,
bc65ccee 907.Xr btxld 8 ,
24d322d7
TN
908.Xr loader.4th 8 ,
909.Xr sysctl 8
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910.Sh STANDARDS
911For the purposes of ANS Forth compliance, loader is an
912.Bf Em
913ANS Forth System with Environmental Restrictions, Providing
914.Ef
915.Bf Li
916.No .( ,
917.No :noname ,
918.No ?do ,
919parse, pick, roll, refill, to, value, \e, false, true,
920.No <> ,
921.No 0<> ,
922compile\&, , erase, nip, tuck
923.Ef
924.Em and
925.Li marker
926.Bf Em
927from the Core Extensions word set, Providing the Exception Extensions
928word set, Providing the Locals Extensions word set, Providing the
929Memory-Allocation Extensions word set, Providing
930.Ef
931.Bf Li
932\&.s,
933bye, forget, see, words,
934\&[if],
935\&[else]
936.Ef
937.Em and
938.Li [then]
939.Bf Em
940from the Programming-Tools extension word set, Providing the
941Search-Order extensions word set.
942.Ef
943.Sh HISTORY
5ee58eed 944The
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945.Nm
946first appeared in
947.Fx 3.1 .
948.Sh AUTHORS
949.An -nosplit
5ee58eed 950The
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951.Nm
952was written by
953.An Michael Smith Aq msmith@FreeBSD.org .
954.Pp
955.Tn FICL
956was written by
957.An John Sadler Aq john_sadler@alum.mit.edu .
958.Sh BUGS
959The
960.Ic expect
961and
962.Ic accept
963words will read from the input buffer instead of the console.
964The latter will be fixed, but the former will not.