ioctl_kd(2) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | STANDARDS | SEE ALSO | COLOPHON

ioctl_kd(2)                System Calls Manual               ioctl_kd(2)

NAME         top

       ioctl_kd - ioctls for console terminal and virtual consoles

SYNOPSIS         top

       #include <linux/kd.h>  /* Definition of op constants */
       #include <sys/ioctl.h>

       int ioctl(int fd, unsigned long op, void *argp);

DESCRIPTION         top

       The following Linux-specific ioctl(2) operations are supported
       for console terminals and virtual consoles.

       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
              LED_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 the unsigned long integer in 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 Linux 1.1.54, the LEDs just reflected the state of the
       corresponding keyboard flags, and KDGETLED/KDSETLED would also
       change the keyboard flags.  Since Linux 1.1.54 the LEDs can be
       made to display arbitrary information, 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
              Linux 1.1.54.)

       KDSKBLED
              Set keyboard flags CapsLock, NumLock, ScrollLock (not
              lights).  argp is an unsigned long integer that 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
              Linux 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,
              0x3df-0x3b4+1, 0).

       KDSETMODE
              Set text/graphics mode.  argp is an unsigned integer
              containing one of:
              KD_TEXT       0x00
              KD_GRAPHICS   0x01

       KDGETMODE
              Get text/graphics mode.  argp points to an int which is
              set to one of the values shown above for KDSETMODE.

       KDMKTONE
              Generate tone of specified length.  The lower 16 bits of
              the unsigned long integer in 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 Linux 0.99pl1;
              broken in Linux 2.1.49-50.)

       KIOCSOUND
              Start or stop sound generation.  The lower 16 bits of argp
              specify the period in clock cycles (that is, argp =
              1193180/frequency).  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 Linux 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 Linux 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 currently 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 Linux 1.3.1.)

       PIO_FONT
              Sets 256-character screen font.  Load font into the
              EGA/VGA character generator.  argp points to an 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 points to a

                  struct consolefontdesc {
                      unsigned short charcount;  /* characters in font
                                                    (256 or 512) */
                      unsigned short charheight; /* scan lines per
                                                    character (1-32) */
                      char          *chardata;   /* font data in
                                                    expanded form */
                  };

              If necessary, the screen will be appropriately resized,
              and SIGWINCH sent to the appropriate processes.  This call
              also invalidates the Unicode mapping.  (Since Linux
              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 Linux 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 information 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 Linux 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
              Linux 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 Linux 1.1.92.)

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

       PIO_UNIMAPCLR
              Clear table, possibly advise hash algorithm.  argp points
              to a

                  struct unimapinit {
                      unsigned short advised_hashsize;  /* 0 if no opinion */
                      unsigned short advised_hashstep;  /* 0 if no opinion */
                      unsigned short advised_hashlevel; /* 0 if no opinion */
                  };

              (Since Linux 1.1.92.)

       KDGKBMODE
              Gets current keyboard mode.  argp points to a long which
              is set to one of these:
              K_RAW         0x00  /* Raw (scancode) mode */
              K_XLATE       0x01  /* Translate keycodes using keymap */
              K_MEDIUMRAW   0x02  /* Medium raw (scancode) mode */
              K_UNICODE     0x03  /* Unicode mode */
              K_OFF         0x04  /* Disabled mode; since Linux 2.6.39 */

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

       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 values shown above for KDGKBMETA.

       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 keycode (0 <= kb_index < NR_KEYS).  kb_value is set
              to the corresponding 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
              Sets one function key string entry.  argp points to a
              struct kbsentry.

       KDGKBDIACR
              Read kernel accent table.  argp points to a

                  struct kbdiacrs {
                      unsigned int   kb_cnt;
                      struct kbdiacr kbdiacr[256];
                  };

              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==scancode.)  (Since Linux 1.1.63.)

       KDSETKEYCODE
              Write kernel keycode table entry.  argp points to a struct
              kbkeycode.  (Since Linux 1.1.63.)

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

RETURN VALUE         top

       On success, 0 is returned (except where indicated).  On failure,
       -1 is returned, and errno is set to indicate the error.

ERRORS         top

       EINVAL argp is invalid.

STANDARDS         top

       Linux.

SEE ALSO         top

       ioctl(2), ioctl_console(2)

COLOPHON         top

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Linux man-pages 6.9.1          2024-06-13                    ioctl_kd(2)

Pages that refer to this page: ioctl_console(2)