src/core/pc_kbd.c

   1 /* Minimal polling PC keyboard driver
   2  * - No interrupt
   3  * - No LED
   4  * - No special keys
   5  *
   6  * still Enough For Me to type a filename.
   7  *
   8  * 2003-07 by SONE Takesh
   9  * 2004-04 moved by LYH From filo to Etherboot
  10  *              yhlu@tyan.com
  11  */
  12
  13 #include <gpxe/io.h>
  14 #include "console.h"
  15
  16 static char key_map[][128] = {
  17     {
  18         "\0\x1b""1234567890-=\b\t"
  19         "qwertyuiop[]\r\0as"
  20         "dfghjkl;'`\0\\zxcv"
  21         "bnm,./\0*\0 \0\0\0\0\0\0"
  22         "\0\0\0\0\0\0\0""789-456+1"
  23         "230."
  24     },{
  25         "\0\x1b""!@#$%^&*()_+\b\t"
  26         "QWERTYUIOP{}\r\0AS"
  27         "DFGHJKL:\"~\0|ZXCV"
  28         "BNM<>?\0\0\0 \0\0\0\0\0\0"
  29         "\0\0\0\0\0\0\0""789-456+1"
  30         "230."
  31     }
  32 };
  33
  34 static int cur_scan;
  35 static unsigned int shift_state;
  36 #define SHIFT 1
  37 #define CONTROL 2
  38 #define CAPS 4
  39
  40 static int get_scancode(void)
  41 {
  42     int scan;
  43
  44     if ((inb(0x64) & 1) == 0)
  45         return 0;
  46     scan = inb(0x60);
  47
  48     switch (scan) {
  49     case 0x2a:
  50     case 0x36:
  51         shift_state |= SHIFT;
  52         break;
  53     case 0xaa:
  54     case 0xb6:
  55         shift_state &= ~SHIFT;
  56         break;
  57     case 0x1d:
  58         shift_state |= CONTROL;
  59         break;
  60     case 0x9d:
  61         shift_state &= ~CONTROL;
  62         break;
  63     case 0x3a:
  64         shift_state ^= CAPS;
  65         break;
  66     }
  67
  68     if (scan & 0x80)
  69         return 0; /* ignore break code or 0xe0 etc! */
  70     return scan;
  71 }
  72
  73 static int kbd_havekey(void)
  74 {
  75     if (!cur_scan)
  76         cur_scan = get_scancode();
  77     return cur_scan != 0;
  78 }
  79
  80 static int kbd_ischar(void)
  81 {
  82     if (!kbd_havekey())
  83         return 0;
  84     if (!key_map[shift_state & SHIFT][cur_scan]) {
  85         cur_scan = 0;
  86         return 0;
  87     }
  88     return 1;
  89 }
  90
  91 static int kbd_getc(void)
  92 {
  93     int c;
  94
  95     while (!kbd_ischar())
  96         ;
  97     c = key_map[shift_state & SHIFT][cur_scan];
  98     if (shift_state & (CONTROL | CAPS)) {
  99         if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) {
 100             if (shift_state & CONTROL)
 101                 c &= 0x1f;
 102             else if (shift_state & CAPS)
 103                 c ^= ('A' ^ 'a');
 104         }
 105     }
 106     cur_scan = 0;
 107     return c;
 108 }
 109
 110 struct console_driver pc_kbd_console __console_driver = {
 111         .getchar = kbd_getc,
 112 };