sos

[unmaintained] experimenting with low level OS development
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keyboard.c (2703B)

      1 // This file contains general functions that are used as an interface
      2 // to other parts of the kernel and to user space programs, and are used
      3 // by all keyboard drivers (e.g. PS2 and others) the same
      4 
      5 #include "keyboard.h"
      6 
      7 static int keyboard_callbacks_pos = 0;
      8 static void (*keyboard_callbacks[MAX_CALLBACK_COUNT])(struct keyboard_event);
      9 
     10 // TODO: As long as we cannot allocate memory dynamically, use fixed one
     11 static struct keyboard_event kbd_event;
     12 
     13 static bool shift_active = false;
     14 
     15 static bool keycode_is_printable[256] = {
     16     1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     17 
     18     1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     19     1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     20     1, 1, 1, 1, 1, 1,
     21 
     22     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     23 
     24     1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0,
     25 
     26     0 ,0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0,
     27 
     28     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     29 
     30     0
     31 };
     32 
     33 static char keycode_to_char[256] = {
     34     '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
     35     'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o' ,'p', 'a', 's', 'd', 'f',
     36     'g', 'h', 'j', 'k', 'l', 'z', 'x', 'c', 'v', 'b', 'n', 'm',
     37 
     38     ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
     39 
     40     ',', '.', '/', '\\', '\'', ';', '-', '=', ' ', ' ', ' ', '\t', ' ',
     41 
     42     ' ', ' ', ' ', ' ', ' ', ' ', ' ', ']', '[', ' ', ' ', ' ',
     43 
     44     '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '*', '+', '.',
     45 
     46     ' '
     47 };
     48 
     49 static char keycode_to_char_shift[256] = {
     50     '!', '@', '#', '$', '%', '^', '&', '*', '(', ')',
     51     'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O' ,'P', 'A', 'S', 'D', 'F',
     52     'G', 'H', 'J', 'K', 'L', 'Z', 'X', 'C', 'V', 'B', 'N', 'M',
     53 
     54     ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
     55 
     56     '<', '>', '?', '|', '"', ':', '_', '+', ' ', ' ', ' ', '\t', ' ',
     57 
     58     ' ', ' ', ' ', ' ', ' ', ' ', ' ', '}', '{', ' ', ' ', ' ',
     59 
     60     '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '*', '+', '.',
     61 
     62     ' '
     63 };
     64 
     65 void keyboard_add_callback(void (*callback)(struct keyboard_event)) {
     66     keyboard_callbacks[keyboard_callbacks_pos] = callback;
     67     keyboard_callbacks_pos++;
     68 }
     69 
     70 void keyboard_fire_event(enum keyboard_key kbdkey, bool released) {
     71     if (kbdkey == KEY_LSHIFT || kbdkey == KEY_RSHIFT) {
     72         shift_active = !released;
     73     }
     74 
     75     kbd_event.key = kbdkey;
     76     kbd_event.released = released;
     77 
     78     // TODO: We should make sure that they always match?
     79     if (kbdkey < 256) {
     80         kbd_event.printable = keycode_is_printable[kbdkey];
     81 
     82         if (shift_active) {
     83             kbd_event.ascii = keycode_to_char_shift[kbdkey];
     84         } else {
     85             kbd_event.ascii = keycode_to_char[kbdkey];
     86         }
     87     }
     88 
     89     for (int i = 0; i < keyboard_callbacks_pos; i++) {
     90         keyboard_callbacks[i](kbd_event);
     91     }
     92 }