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 ioctls 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 the first N of them are used for an
              8xN font (0 < N <= 32).  This call also invalidates the  Unicode
              mapping.

       PIO_FONTX
              Sets  screen  font  and  associated rendering information.  argp
              WINCH sent to the appropriate processes.  This call also invali-
              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)

              Gets current keyboard mode.  argp points to a long which is  set
              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
                  };

              where kb_cnt is the number of entries  in  the  array,  each  of
              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:


                      unsigned short v_signal;  /* signal to send */
                      unsigned short v_state;   /* vt bit mask */
                  };

              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 {
                     char  subcode;
                     short xs, ys, xe, ye;
                     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

ERRORS
       errno may take on these values:

       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  ioctls.  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, ioctls 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 ioctls 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 3.54 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.



Linux                             2009-02-28                  CONSOLE_IOCTL(4)
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