console_ioctl


DESCRIPTION
       The  following  Linux-specific  ioctl(2)  requests are supported.  Each
       requires a third argument, assumed here to be argp.

       KDGETLED
              Get state of LEDs.  argp points to a char.  The lower three bits
              of *argp are set to the state of the LEDs, as follows:

                  LED_CAP       0x04   caps lock led
                  LEC_NUM       0x02   num lock led
                  LED_SCR       0x01   scroll lock led

       KDSETLED
              Set the LEDs.  The LEDs are set to correspond to the lower three
              bits of argp.  However, if a higher order bit is set,  the  LEDs
              revert to normal: displaying the state of the keyboard functions
              of caps lock, num lock, and scroll lock.

       Before 1.1.54, the LEDs just reflected the state of  the  corresponding
       keyboard  flags,  and  KDGETLED/KDSETLED would also change the keyboard
       flags.  Since 1.1.54 the leds can be made to display arbitrary informa-
       tion,  but  by  default they display the keyboard flags.  The following
       two ioctl's are used to access the keyboard flags.

       KDGKBLED
              Get keyboard flags CapsLock, NumLock, ScrollLock  (not  lights).
              argp  points  to a char which is set to the flag state.  The low
              order three bits (mask 0x7) get the current flag state, and  the
              low  order  bits  of the next nibble (mask 0x70) get the default
              flag state.  (Since 1.1.54.)

       KDSKBLED
              Set keyboard flags CapsLock, NumLock, ScrollLock  (not  lights).
              argp has the desired flag state.  The low order three bits (mask
              0x7) have the flag state, and the low order  bits  of  the  next
              nibble (mask 0x70) have the default flag state.  (Since 1.1.54.)

       KDGKBTYPE
              Get  keyboard  type.   This returns the value KB_101, defined as
              0x02.

       KDADDIO
              Add I/O port as valid.  Equivalent to ioperm(arg,1,1).

       KDDELIO
              Delete I/O port as valid.  Equivalent to ioperm(arg,1,0).

       KDENABIO
              Enable  I/O  to  video  board.   Equivalent   to   ioperm(0x3b4,
              0x3df-0x3b4+1, 1).

       KDDISABIO
              Disable   I/O  to  video  board.   Equivalent  to  ioperm(0x3b4,

       KDMKTONE
              Generate  tone  of  specified length.  The lower 16 bits of argp
              specify the period in clock cycles, and the upper 16  bits  give
              the  duration  in  msec.   If the duration is zero, the sound is
              turned off.  Control returns immediately.  For example,  argp  =
              (125<<16)  +  0x637  would  specify the beep normally associated
              with a ctrl-G.  (Thus since 0.99pl1; broken in 2.1.49-50.)

       KIOCSOUND
              Start or stop sound generation.  The lower 16 bits of argp spec-
              ify  the  period  in  clock cycles (that is, argp = 1193180/fre-
              quency).  argp = 0 turns sound off.   In  either  case,  control
              returns immediately.

       GIO_CMAP
              Get the current default color map from kernel.  argp points to a
              48-byte array.  (Since 1.3.3.)

       PIO_CMAP
              Change the default  text-mode  color  map.   argp  points  to  a
              48-byte array which contains, in order, the Red, Green, and Blue
              values for the 16 available screen colors: 0 is off, and 255  is
              full  intensity.   The default colors are, in order: black, dark
              red, dark green, brown, dark blue, dark purple, dark cyan, light
              grey,  dark grey, bright red, bright green, yellow, bright blue,
              bright purple, bright cyan and white.  (Since 1.3.3.)

       GIO_FONT
              Gets 256-character screen font in expanded form.  argp points to
              an  8192  byte  array.  Fails with error code EINVAL if the cur-
              rently loaded font is a 512-character font, or if the console is
              not in text mode.

       GIO_FONTX
              Gets  screen  font and associated information.  argp points to a
              struct consolefontdesc (see PIO_FONTX).  On call, the  charcount
              field  should  be  set  to the maximum number of characters that
              would fit in the buffer pointed to by chardata.  On return,  the
              charcount and charheight are filled with the respective data for
              the currently loaded font, and the chardata array  contains  the
              font  data  if  the  initial value of charcount indicated enough
              space was available; otherwise the buffer is untouched and errno
              is set to ENOMEM.  (Since 1.3.1.)

       PIO_FONT
              Sets  256-character  screen  font.   Load  font into the EGA/VGA
              character generator.  argp points to a 8192 byte  map,  with  32
              bytes  per  character.  Only first N of them are used for an 8xN
              font (0 < N <= 32).  This call also invalidates the Unicode map-
              ping.

       PIO_FONTX
              Sets  screen  font  and  associated rendering information.  argp
              points to a
              dates the Unicode mapping.  (Since 1.3.1.)

       PIO_FONTRESET
              Resets the screen font, size and Unicode mapping to  the  bootup
              defaults.   argp  is unused, but should be set to NULL to ensure
              compatibility with future versions of Linux.  (Since 1.3.28.)

       GIO_SCRNMAP
              Get screen mapping from kernel.  argp points to an area of  size
              E_TABSZ, which is loaded with the font positions used to display
              each character.  This call is likely to return useless  informa-
              tion if the currently loaded font is more than 256 characters.

       GIO_UNISCRNMAP
              Get  full Unicode screen mapping from kernel.  argp points to an
              area of size E_TABSZ*sizeof(unsigned  short),  which  is  loaded
              with  the  Unicodes  each character represent.  A special set of
              Unicodes, starting at U+F000, are used to represent  "direct  to
              font" mappings.  (Since 1.3.1.)

       PIO_SCRNMAP
              Loads  the  "user  definable" (fourth) table in the kernel which
              maps bytes into console screen symbols.  argp points to an  area
              of size E_TABSZ.

       PIO_UNISCRNMAP
              Loads  the  "user  definable" (fourth) table in the kernel which
              maps bytes into Unicodes, which are then translated into  screen
              symbols  according  to the currently loaded Unicode-to-font map.
              Special Unicodes starting at U+F000 can be used to map  directly
              to the font symbols.  (Since 1.3.1.)

       GIO_UNIMAP
              Get Unicode-to-font mapping from kernel.  argp points to a

                  struct unimapdesc {
                      unsigned short  entry_ct;
                      struct unipair *entries;
                  };

              where entries points to an array of

                  struct unipair {
                      unsigned short unicode;
                      unsigned short fontpos;
                  };

              (Since 1.1.92.)

       PIO_UNIMAP
              Put unicode-to-font mapping in kernel.
                  argp points to a struct unimapdesc.  (Since 1.1.92)

       PIO_UNIMAPCLR
              to one of these:

                  K_RAW         0x00
                  K_XLATE       0x01
                  K_MEDIUMRAW   0x02
                  K_UNICODE     0x03

       KDSKBMODE
              Sets current keyboard mode.  argp is a long equal to one of  the
              above values.

       KDGKBMETA
              Gets meta key handling mode.  argp points to a long which is set
              to one of these:

                  K_METABIT     0x03   set high order bit
                  K_ESCPREFIX   0x04   escape prefix

       KDSKBMETA
              Sets meta key handling mode.  argp is a long equal to one of the
              above values.

       KDGKBENT
              Gets  one  entry  in  key  translation  table (keycode to action
              code).  argp points to a

                  struct kbentry {
                      unsigned char  kb_table;
                      unsigned char  kb_index;
                      unsigned short kb_value;
                  };

              with the first two members filled in: kb_table selects  the  key
              table (0 <= kb_table < MAX_NR_KEYMAPS), and kb_index is the key-
              code (0 <= kb_index < NR_KEYS).  kb_value is set to  the  corre-
              sponding  action  code,  or  K_HOLE  if there is no such key, or
              K_NOSUCHMAP if kb_table is invalid.

       KDSKBENT
              Sets one entry in translation table.  argp points  to  a  struct
              kbentry.

       KDGKBSENT
              Gets one function key string.  argp points to a

                  struct kbsentry {
                      unsigned char kb_func;
                      unsigned char kb_string[512];
                  };

              kb_string  is  set to the (null-terminated) string corresponding
              to the kb_functh function key action code.

       KDSKBSENT
              which is a

                  struct kbdiacr {
                      unsigned char diacr;
                      unsigned char base;
                      unsigned char result;
                  };

       KDGETKEYCODE
              Read kernel keycode table entry (scan code  to  keycode).   argp
              points to a

                  struct kbkeycode {
                      unsigned int scancode;
                      unsigned int keycode;
                  };

              keycode  is  set  to  correspond  to the given scancode.  (89 <=
              scancode <= 255 only.  For 1 <= scancode <=  88,  keycode==scan-
              code.)  (Since 1.1.63.)

       KDSETKEYCODE
              Write  kernel keycode table entry.  argp points to a struct kbk-
              eycode.  (Since 1.1.63.)

       KDSIGACCEPT
              The calling process indicates its willingness to accept the sig-
              nal  argp  when  it  is generated by pressing an appropriate key
              combination.  (1 <= argp  <=  NSIG).   (See  spawn_console()  in
              linux/drivers/char/keyboard.c.)

       VT_OPENQRY
              Returns  the  first available (non-opened) console.  argp points
              to an int which is set to the number of the vt (1  <=  *argp  <=
              MAX_NR_CONSOLES).

       VT_GETMODE
              Get mode of active vt.  argp points to a

                  struct vt_mode {
                      char  mode;    /* vt mode */
                      char  waitv;   /* if set, hang on writes if not active */
                      short relsig;  /* signal to raise on release req */
                      short acqsig;  /* signal to raise on acquisition */
                      short frsig;   /* unused (set to 0) */
                  };

              which  is  set to the mode of the active vt.  mode is set to one
              of these values:

                  VT_AUTO       auto vt switching
                  VT_PROCESS    process controls switching
                  VT_ACKACQ     acknowledge switch

              For each vt in use, the corresponding bit in the v_state  member
              is set.  (Kernels 1.0 through 1.1.92.)

       VT_RELDISP
              Release a display.

       VT_ACTIVATE
              Switch to vt argp (1 <= argp <= MAX_NR_CONSOLES).

       VT_WAITACTIVE
              Wait until vt argp has been activated.

       VT_DISALLOCATE
              Deallocate the memory associated with vt argp.  (Since 1.1.54.)

       VT_RESIZE
              Set the kernel's idea of screensize.  argp points to a

                  struct vt_sizes {
                      unsigned short v_rows;       /* # rows */
                      unsigned short v_cols;       /* # columns */
                      unsigned short v_scrollsize; /* no longer used */
                  };

              Note  that  this  does  not  change  the videomode.  See resize-
              cons(8).  (Since 1.1.54.)

       VT_RESIZEX
              Set the kernel's idea of various screen parameters.  argp points
              to a

                  struct vt_consize {
                      unsigned short v_rows;  /* number of rows */
                      unsigned short v_cols;  /* number of columns */
                      unsigned short v_vlin;  /* number of pixel rows
                                                 on screen */
                      unsigned short v_clin;  /* number of pixel rows
                                                 per character */
                      unsigned short v_vcol;  /* number of pixel columns
                                                 on screen */
                      unsigned short v_ccol;  /* number of pixel columns
                                                 per character */
                  };

              Any parameter may be set to zero, indicating "no change", but if
              multiple parameters are set, they must be self-consistent.  Note
              that  this  does  not  change the videomode.  See resizecons(8).
              (Since 1.3.3.)

       The action of the following ioctls depends on the  first  byte  in  the
       struct  pointed to by argp, referred to here as the subcode.  These are
       legal only for the superuser or the owner of the current tty.

       TIOCLINUX, subcode=0
                     short sel_mode;
                  };

              xs  and  ys  are the starting column and row.  xe and ye are the
              ending column and row.  (Upper  left  corner  is  row=column=1.)
              sel_mode  is 0 for character-by-character selection, 1 for word-
              by-word selection, or 2 for line-by-line selection.   The  indi-
              cated  screen characters are highlighted and saved in the static
              array sel_buffer in devices/char/console.c.

       TIOCLINUX, subcode=3
              Paste selection.  The characters in  the  selection  buffer  are
              written to fd.

       TIOCLINUX, subcode=4
              Unblank the screen.

       TIOCLINUX, subcode=5
              Sets  contents of a 256-bit look up table defining characters in
              a "word", for word-by-word selection.  (Since 1.1.32.)

       TIOCLINUX, subcode=6
              argp points to a char which is set to the value  of  the  kernel
              variable shift_state.  (Since 1.1.32.)

       TIOCLINUX, subcode=7
              argp  points  to  a char which is set to the value of the kernel
              variable report_mouse.  (Since 1.1.33.)

       TIOCLINUX, subcode=8
              Dump screen width and height, cursor position, and all the char-
              acter-attribute  pairs.   (Kernels  1.1.67  through 1.1.91 only.
              With kernel 1.1.92 or later, read from /dev/vcsa* instead.)

       TIOCLINUX, subcode=9
              Restore screen width and height, cursor position,  and  all  the
              character-attribute pairs.  (Kernels 1.1.67 through 1.1.91 only.
              With kernel 1.1.92 or later, write to /dev/vcsa* instead.)

       TIOCLINUX, subcode=10
              Handles the Power Saving feature of the new generation of  moni-
              tors.   VESA  screen blanking mode is set to argp[1], which gov-
              erns what screen blanking does:

                  0: Screen blanking is disabled.

                  1: The current video adapter register  settings  are  saved,
              then  the controller is programmed to turn off the vertical syn-
              chronization pulses.  This puts the monitor into "standby" mode.
              If  your  monitor has an Off_Mode timer, then it will eventually
              power down by itself.

                  2: The current settings are saved, then  both  the  vertical
              and horizontal synchronization pulses are turned off.  This puts

       EBADF  The file descriptor is invalid.

       ENOTTY The  file  descriptor is not associated with a character special
              device, or the specified request does not apply to it.

       EINVAL The file descriptor or argp is invalid.

       EPERM  Insufficient permission.

NOTES
       Warning: Do not regard this man page as documentation of the Linux con-
       sole ioctl's.  This is provided for the curious only, as an alternative
       to reading the  source.   Ioctl's  are  undocumented  Linux  internals,
       liable  to  be changed without warning.  (And indeed, this page more or
       less describes the situation as of kernel  version  1.1.94;  there  are
       many minor and not-so-minor differences with earlier versions.)

       Very often, ioctl's are introduced for communication between the kernel
       and  one  particular  well-known  program  (fdisk,  hdparm,  setserial,
       tunelp, loadkeys, selection, setfont, etc.), and their behavior will be
       changed when required by this particular program.

       Programs using these ioctl's will not be portable to other versions  of
       UNIX,  will  not  work on older versions of Linux, and will not work on
       future versions of Linux.

       Use POSIX functions.

SEE ALSO
       dumpkeys(1), kbd_mode(1), loadkeys(1), mknod(1),  setleds(1),  setmeta-
       mode(1),  execve(2),  fcntl(2), ioperm(2), termios(3), console(4), con-
       sole_codes(4), mt(4), sd(4),  tty(4),  tty_ioctl(4),  ttyS(4),  vcs(4),
       vcsa(4),    charsets(7),    mapscrn(8),    resizecons(8),   setfont(8),
       /usr/include/linux/kd.h, /usr/include/linux/vt.h

COLOPHON
       This page is part of release 3.35 of the Linux  man-pages  project.   A
       description  of  the project, and information about reporting bugs, can
       be found at http://man7.org/linux/man-pages/.



Linux                             2009-02-28                  CONSOLE_IOCTL(4)
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