1CONSOLE_IOCTL(4) Linux Programmer's Manual CONSOLE_IOCTL(4)
2
6 console_ioctl - ioctl's for console terminal and virtual consoles
7
9 The following Linux-specific ioctl(2) requests are supported. Each
10 requires a third argument, assumed here to be argp.
11 KDGETLED
13 Get state of LEDs. argp points to a char. The lower three bits
14 of *argp are set to the state of the LEDs, as follows:
15 LED_CAP 0x04 caps lock led
17 LEC_NUM 0x02 num lock led
18 LED_SCR 0x01 scroll lock led
19 KDSETLED
21 Set the LEDs. The LEDs are set to correspond to the lower three
22 bits of argp. However, if a higher order bit is set, the LEDs
23 revert to normal: displaying the state of the keyboard functions
24 of caps lock, num lock, and scroll lock.
25 Before 1.1.54, the LEDs just reflected the state of the corresponding
27 keyboard flags, and KDGETLED/KDSETLED would also change the keyboard
28 flags. Since 1.1.54 the leds can be made to display arbitrary informa‐
29 tion, but by default they display the keyboard flags. The following
30 two ioctl's are used to access the keyboard flags.
31 KDGKBLED
33 Get keyboard flags CapsLock, NumLock, ScrollLock (not lights).
34 argp points to a char which is set to the flag state. The low
35 order three bits (mask 0x7) get the current flag state, and the
36 low order bits of the next nibble (mask 0x70) get the default
37 flag state. (Since 1.1.54.)
38 KDSKBLED
40 Set keyboard flags CapsLock, NumLock, ScrollLock (not lights).
41 argp has the desired flag state. The low order three bits (mask
42 0x7) have the flag state, and the low order bits of the next
43 nibble (mask 0x70) have the default flag state. (Since 1.1.54.)
44 KDGKBTYPE
46 Get keyboard type. This returns the value KB_101, defined as
47 0x02.
48 KDADDIO
50 Add I/O port as valid. Equivalent to ioperm(arg,1,1).
51 KDDELIO
53 Delete I/O port as valid. Equivalent to ioperm(arg,1,0).
54 KDENABIO
56 Enable I/O to video board. Equivalent to ioperm(0x3b4,
57 0x3df-0x3b4+1, 1).
58 KDDISABIO
60 Disable I/O to video board. Equivalent to ioperm(0x3b4,
61 0x3df-0x3b4+1, 0).
62 KDSETMODE
64 Set text/graphics mode. argp is one of these:
65 KD_TEXT 0x00
67 KD_GRAPHICS 0x01
68 KDGETMODE
70 Get text/graphics mode. argp points to a long which is set to
71 one of the above values.
72 KDMKTONE
74 Generate tone of specified length. The lower 16 bits of argp
75 specify the period in clock cycles, and the upper 16 bits give
76 the duration in msec. If the duration is zero, the sound is
77 turned off. Control returns immediately. For example, argp =
78 (125<<16) + 0x637 would specify the beep normally associated
79 with a ctrl-G. (Thus since 0.99pl1; broken in 2.1.49-50.)
80 KIOCSOUND
82 Start or stop sound generation. The lower 16 bits of argp spec‐
83 ify the period in clock cycles (that is, argp = 1193180/fre‐
84 quency). argp = 0 turns sound off. In either case, control
85 returns immediately.
86 GIO_CMAP
88 Get the current default color map from kernel. argp points to a
89 48-byte array. (Since 1.3.3.)
90 PIO_CMAP
92 Change the default text-mode color map. argp points to a
93 48-byte array which contains, in order, the Red, Green, and Blue
94 values for the 16 available screen colors: 0 is off, and 255 is
95 full intensity. The default colors are, in order: black, dark
96 red, dark green, brown, dark blue, dark purple, dark cyan, light
97 grey, dark grey, bright red, bright green, yellow, bright blue,
98 bright purple, bright cyan and white. (Since 1.3.3.)
99 GIO_FONT
101 Gets 256-character screen font in expanded form. argp points to
102 an 8192 byte array. Fails with error code EINVAL if the cur‐
103 rently loaded font is a 512-character font, or if the console is
104 not in text mode.
105 GIO_FONTX
107 Gets screen font and associated information. argp points to a
108 struct consolefontdesc (see PIO_FONTX). On call, the charcount
109 field should be set to the maximum number of characters that
110 would fit in the buffer pointed to by chardata. On return, the
111 charcount and charheight are filled with the respective data for
112 the currently loaded font, and the chardata array contains the
113 font data if the initial value of charcount indicated enough
114 space was available; otherwise the buffer is untouched and errno
115 is set to ENOMEM. (Since 1.3.1.)
116 PIO_FONT
118 Sets 256-character screen font. Load font into the EGA/VGA
119 character generator. argp points to a 8192 byte map, with 32
120 bytes per character. Only first N of them are used for an 8xN
121 font (0 < N <= 32). This call also invalidates the Unicode map‐
122 ping.
123 PIO_FONTX
125 Sets screen font and associated rendering information. argp
126 points to a
127 struct consolefontdesc {
129 unsigned short charcount; /* characters in font
130 (256 or 512) */
131 unsigned short charheight; /* scan lines per
132 character (1-32) */
133 char *chardata; /* font data in
134 expanded form */
135 };
136 If necessary, the screen will be appropriately resized, and SIG‐
138 WINCH sent to the appropriate processes. This call also invali‐
139 dates the Unicode mapping. (Since 1.3.1.)
140 PIO_FONTRESET
142 Resets the screen font, size and Unicode mapping to the bootup
143 defaults. argp is unused, but should be set to NULL to ensure
144 compatibility with future versions of Linux. (Since 1.3.28.)
145 GIO_SCRNMAP
147 Get screen mapping from kernel. argp points to an area of size
148 E_TABSZ, which is loaded with the font positions used to display
149 each character. This call is likely to return useless informa‐
150 tion if the currently loaded font is more than 256 characters.
151 GIO_UNISCRNMAP
153 Get full Unicode screen mapping from kernel. argp points to an
154 area of size E_TABSZ*sizeof(unsigned short), which is loaded
155 with the Unicodes each character represent. A special set of
156 Unicodes, starting at U+F000, are used to represent "direct to
157 font" mappings. (Since 1.3.1.)
158 PIO_SCRNMAP
160 Loads the "user definable" (fourth) table in the kernel which
161 maps bytes into console screen symbols. argp points to an area
162 of size E_TABSZ.
163 PIO_UNISCRNMAP
165 Loads the "user definable" (fourth) table in the kernel which
166 maps bytes into Unicodes, which are then translated into screen
167 symbols according to the currently loaded Unicode-to-font map.
168 Special Unicodes starting at U+F000 can be used to map directly
169 to the font symbols. (Since 1.3.1.)
170 GIO_UNIMAP
172 Get Unicode-to-font mapping from kernel. argp points to a
173 struct unimapdesc {
175 unsigned short entry_ct;
176 struct unipair *entries;
177 };
178 where entries points to an array of
180 struct unipair {
182 unsigned short unicode;
183 unsigned short fontpos;
184 };
185 (Since 1.1.92.)
187 PIO_UNIMAP
189 Put unicode-to-font mapping in kernel.
190 argp points to a struct unimapdesc. (Since 1.1.92)
191 PIO_UNIMAPCLR
193 Clear table, possibly advise hash algorithm. argp points to a
194 struct unimapinit {
196 unsigned short advised_hashsize; /* 0 if no opinion */
197 unsigned short advised_hashstep; /* 0 if no opinion */
198 unsigned short advised_hashlevel; /* 0 if no opinion */
199 };
200 (Since 1.1.92.)
202 KDGKBMODE
204 Gets current keyboard mode. argp points to a long which is set
205 to one of these:
206 K_RAW 0x00
208 K_XLATE 0x01
209 K_MEDIUMRAW 0x02
210 K_UNICODE 0x03
211 KDSKBMODE
213 Sets current keyboard mode. argp is a long equal to one of the
214 above values.
215 KDGKBMETA
217 Gets meta key handling mode. argp points to a long which is set
218 to one of these:
219 K_METABIT 0x03 set high order bit
221 K_ESCPREFIX 0x04 escape prefix
222 KDSKBMETA
224 Sets meta key handling mode. argp is a long equal to one of the
225 above values.
226 KDGKBENT
228 Gets one entry in key translation table (keycode to action
229 code). argp points to a
230 struct kbentry {
232 unsigned char kb_table;
233 unsigned char kb_index;
234 unsigned short kb_value;
235 };
236 with the first two members filled in: kb_table selects the key
238 table (0 <= kb_table < MAX_NR_KEYMAPS), and kb_index is the key‐
239 code (0 <= kb_index < NR_KEYS). kb_value is set to the corre‐
240 sponding action code, or K_HOLE if there is no such key, or
241 K_NOSUCHMAP if kb_table is invalid.
242 KDSKBENT
244 Sets one entry in translation table. argp points to a struct
245 kbentry.
246 KDGKBSENT
248 Gets one function key string. argp points to a
249 struct kbsentry {
251 unsigned char kb_func;
252 unsigned char kb_string[512];
253 };
254 kb_string is set to the (null-terminated) string corresponding
256 to the kb_functh function key action code.
257 KDSKBSENT
259 Sets one function key string entry. argp points to a struct
260 kbsentry.
261 KDGKBDIACR
263 Read kernel accent table. argp points to a
264 struct kbdiacrs {
266 unsigned int kb_cnt;
267 struct kbdiacr kbdiacr[256];
268 };
269 where kb_cnt is the number of entries in the array, each of
271 which is a
272 struct kbdiacr {
274 unsigned char diacr;
275 unsigned char base;
276 unsigned char result;
277 };
278 KDGETKEYCODE
280 Read kernel keycode table entry (scan code to keycode). argp
281 points to a
282 struct kbkeycode {
284 unsigned int scancode;
285 unsigned int keycode;
286 };
287 keycode is set to correspond to the given scancode. (89 <=
289 scancode <= 255 only. For 1 <= scancode <= 88, keycode==scan‐
290 code.) (Since 1.1.63.)
291 KDSETKEYCODE
293 Write kernel keycode table entry. argp points to a struct kbk‐
294 eycode. (Since 1.1.63.)
295 KDSIGACCEPT
297 The calling process indicates its willingness to accept the sig‐
298 nal argp when it is generated by pressing an appropriate key
299 combination. (1 <= argp <= NSIG). (See spawn_console() in
300 linux/drivers/char/keyboard.c.)
301 VT_OPENQRY
303 Returns the first available (non-opened) console. argp points
304 to an int which is set to the number of the vt (1 <= *argp <=
305 MAX_NR_CONSOLES).
306 VT_GETMODE
308 Get mode of active vt. argp points to a
309 struct vt_mode {
311 char mode; /* vt mode */
312 char waitv; /* if set, hang on writes if not active */
313 short relsig; /* signal to raise on release req */
314 short acqsig; /* signal to raise on acquisition */
315 short frsig; /* unused (set to 0) */
316 };
317 which is set to the mode of the active vt. mode is set to one
319 of these values:
320 VT_AUTO auto vt switching
322 VT_PROCESS process controls switching
323 VT_ACKACQ acknowledge switch
324 VT_SETMODE
326 Set mode of active vt. argp points to a struct vt_mode.
327 VT_GETSTATE
329 Get global vt state info. argp points to a
330 struct vt_stat {
332 unsigned short v_active; /* active vt */
333 unsigned short v_signal; /* signal to send */
334 unsigned short v_state; /* vt bit mask */
335 };
336 For each vt in use, the corresponding bit in the v_state member
338 is set. (Kernels 1.0 through 1.1.92.)
339 VT_RELDISP
341 Release a display.
342 VT_ACTIVATE
344 Switch to vt argp (1 <= argp <= MAX_NR_CONSOLES).
345 VT_WAITACTIVE
347 Wait until vt argp has been activated.
348 VT_DISALLOCATE
350 Deallocate the memory associated with vt argp. (Since 1.1.54.)
351 VT_RESIZE
353 Set the kernel's idea of screensize. argp points to a
354 struct vt_sizes {
356 unsigned short v_rows; /* # rows */
357 unsigned short v_cols; /* # columns */
358 unsigned short v_scrollsize; /* no longer used */
359 };
360 Note that this does not change the videomode. See resize‐
362 cons(8). (Since 1.1.54.)
363 VT_RESIZEX
365 Set the kernel's idea of various screen parameters. argp points
366 to a
367 struct vt_consize {
369 unsigned short v_rows; /* number of rows */
370 unsigned short v_cols; /* number of columns */
371 unsigned short v_vlin; /* number of pixel rows
372 on screen */
373 unsigned short v_clin; /* number of pixel rows
374 per character */
375 unsigned short v_vcol; /* number of pixel columns
376 on screen */
377 unsigned short v_ccol; /* number of pixel columns
378 per character */
379 };
380 Any parameter may be set to zero, indicating "no change", but if
382 multiple parameters are set, they must be self-consistent. Note
383 that this does not change the videomode. See resizecons(8).
384 (Since 1.3.3.)
385 The action of the following ioctls depends on the first byte in the
387 struct pointed to by argp, referred to here as the subcode. These are
388 legal only for the superuser or the owner of the current tty.
389 TIOCLINUX, subcode=0
391 Dump the screen. Disappeared in 1.1.92. (With kernel 1.1.92 or
392 later, read from /dev/vcsN or /dev/vcsaN instead.)
393 TIOCLINUX, subcode=1
395 Get task information. Disappeared in 1.1.92.
396 TIOCLINUX, subcode=2
398 Set selection. argp points to a
399 struct {
401 char subcode;
402 short xs, ys, xe, ye;
403 short sel_mode;
404 };
405 xs and ys are the starting column and row. xe and ye are the
407 ending column and row. (Upper left corner is row=column=1.)
408 sel_mode is 0 for character-by-character selection, 1 for word-
409 by-word selection, or 2 for line-by-line selection. The indi‐
410 cated screen characters are highlighted and saved in the static
411 array sel_buffer in devices/char/console.c.
412 TIOCLINUX, subcode=3
414 Paste selection. The characters in the selection buffer are
415 written to fd.
416 TIOCLINUX, subcode=4
418 Unblank the screen.
419 TIOCLINUX, subcode=5
421 Sets contents of a 256-bit look up table defining characters in
422 a "word", for word-by-word selection. (Since 1.1.32.)
423 TIOCLINUX, subcode=6
425 argp points to a char which is set to the value of the kernel
426 variable shift_state. (Since 1.1.32.)
427 TIOCLINUX, subcode=7
429 argp points to a char which is set to the value of the kernel
430 variable report_mouse. (Since 1.1.33.)
431 TIOCLINUX, subcode=8
433 Dump screen width and height, cursor position, and all the char‐
434 acter-attribute pairs. (Kernels 1.1.67 through 1.1.91 only.
435 With kernel 1.1.92 or later, read from /dev/vcsa* instead.)
436 TIOCLINUX, subcode=9
438 Restore screen width and height, cursor position, and all the
439 character-attribute pairs. (Kernels 1.1.67 through 1.1.91 only.
440 With kernel 1.1.92 or later, write to /dev/vcsa* instead.)
441 TIOCLINUX, subcode=10
443 Handles the Power Saving feature of the new generation of moni‐
444 tors. VESA screen blanking mode is set to argp[1], which gov‐
445 erns what screen blanking does:
446 0: Screen blanking is disabled.
448 1: The current video adapter register settings are saved,
450 then the controller is programmed to turn off the vertical syn‐
451 chronization pulses. This puts the monitor into "standby" mode.
452 If your monitor has an Off_Mode timer, then it will eventually
453 power down by itself.
454 2: The current settings are saved, then both the vertical
456 and horizontal synchronization pulses are turned off. This puts
457 the monitor into "off" mode. If your monitor has no Off_Mode
458 timer, or if you want your monitor to power down immediately
459 when the blank_timer times out, then you choose this option.
460 (Caution: Powering down frequently will damage the monitor.)
461 (Since 1.1.76.)
463
465 On success, 0 is returned. On error -1 is returned, and errno is set.
466
468 errno may take on these values:
469 EBADF The file descriptor is invalid.
471 ENOTTY The file descriptor is not associated with a character special
473 device, or the specified request does not apply to it.
474 EINVAL The file descriptor or argp is invalid.
476 EPERM Insufficient permission.
478
480 Warning: Do not regard this man page as documentation of the Linux con‐
481 sole ioctl's. This is provided for the curious only, as an alternative
482 to reading the source. Ioctl's are undocumented Linux internals,
483 liable to be changed without warning. (And indeed, this page more or
484 less describes the situation as of kernel version 1.1.94; there are
485 many minor and not-so-minor differences with earlier versions.)
486 Very often, ioctl's are introduced for communication between the kernel
488 and one particular well-known program (fdisk, hdparm, setserial,
489 tunelp, loadkeys, selection, setfont, etc.), and their behavior will be
490 changed when required by this particular program.
491 Programs using these ioctl's will not be portable to other versions of
493 Unix, will not work on older versions of Linux, and will not work on
494 future versions of Linux.
495 Use POSIX functions.
497
499 dumpkeys(1), kbd_mode(1), loadkeys(1), mknod(1), setleds(1), setmeta‐
500 mode(1), execve(2), fcntl(2), ioperm(2), termios(3), console(4), con‐
501 sole_codes(4), mt(4), sd(4), tty(4), tty_ioctl(4), ttyS(4), vcs(4),
502 vcsa(4), charsets(7), mapscrn(8), resizecons(8), setfont(8),
503 /usr/include/linux/kd.h, /usr/include/linux/vt.h
504
506 This page is part of release 3.25 of the Linux man-pages project. A
507 description of the project, and information about reporting bugs, can
508 be found at http://www.kernel.org/doc/man-pages/.
509Linux 2009-02-28 CONSOLE_IOCTL(4)