kernel/krl_incs/keyboard.inc

   1 ;----------------------------------------------------------;
   2 ; BOS 0.04                  Christoffer Bubach, 2004-2005. ;
   3 ;----------------------------------------------------------;
   4 ;                                                          ;
   5 ;     Keyboard functions. IRQ, INT's and more.             ;
   6 ;                                                          ;
   7 ;----------------------------------------------------------;
   8
   9
  10 ;--------------;
  11 ;  Variabels   ;
  12 ;--------------;
  13
  14      ;--------------------------------------------------------------------------------;
  15      ;   _______________________      Keyboard buffer system                          ;
  16      ;   | | | | | | | | | | | |                                                      ;
  17      ;   +---------------------+                                                      ;
  18      ;      |         +----------> kbd_head, here is where we put new scan-codes.     ;
  19      ;      +--------------------> kbd_tail, where we last read a key. this means     ;
  20      ;                     that we have 4 new scan-codes to read before we catch up.  ;
  21      ;--------------------------------------------------------------------------------;
  22           kbd_buffer      db   '           A 64-byte            '
  23                           db   '        keyboard buffer         '
  24           kbd_head        db   1                      ; head must be +1 from tail
  25           kbd_tail        db   0
  26
  27      ;-------------------------------------------------------------------------;
  28      ; _________________        Flag byte:                                     ;
  29      ; |1|1|0|0|0|1|1|1|                                                       ;
  30      ; +---------------+                     1 = True   0 = False              ;
  31      ;  | | | | | | | +--->  shift key                                         ;
  32      ;  | | | | | | +----->  ctrl key                                          ;
  33      ;  | | | | | +------->  alt key                                           ;
  34      ;  | | | | +--------->  reserved bit                                      ;
  35      ;  | | | +----------->  reserved bit                                      ;
  36      ;  | | +------------->  reserved bit                                      ;
  37      ;  | +--------------->  ctrl + alt + del                                  ;
  38      ;  +----------------->  key released                                      ;
  39      ;-------------------------------------------------------------------------;
  40           kbd_flags       db   0                      ; flag byte
  41
  42      ;-------------------------------------------------------------------------;
  43      ; _________________        LED status byte:                               ;
  44      ; |0|0|0|0|0|1|1|1|                                                       ;
  45      ; +---------------+                     1 = True   0 = False              ;
  46      ;            | | +--->  scroll lock                                       ;
  47      ;            | +----->  num lock                                          ;
  48      ;            +------->  caps lock                                         ;
  49      ;-------------------------------------------------------------------------;
  50           kbd_status      db   0                      ; LED statusbyte
  51
  52
  53 ;----------------------;
  54 ;   Keyboard IRQ       ;
  55 ;----------------------;
  56 keyboard_isr:
  57           push    eax
  58
  59      ;-------------------------;
  60      ;   get the scancode      ;
  61      ;-------------------------;
  62           xor     eax, eax
  63           in      al, 0x60
  64
  65      ;------------------------------;
  66      ;  check if key was released   ;
  67      ;------------------------------;
  68           test    al, 0x80
  69           jz      .key_down
  70           and     byte [kbd_flags], 01111111b         ; key up..
  71
  72           cmp     al, 42+128                          ; left shift up?
  73           je      .shift_up
  74           cmp     al, 54+128                          ; right shift up?
  75           je      .shift_up
  76
  77           cmp     al, 29+128                          ; ctrl up?
  78           je      .ctrl_up
  79
  80           cmp     al, 83+128                          ; del up?
  81           je      .del_up
  82
  83           cmp     al, 56+128                          ; alt up?
  84           je      .alt_up
  85           jmp     .end
  86
  87      ;--------------------;
  88      ;  it was released   ;
  89      ;--------------------;
  90      .shift_up:
  91           and     byte [kbd_flags], 11111110b
  92           jmp     .end
  93
  94      .del_up:
  95           jmp     .CAD_off
  96
  97      .ctrl_up:
  98           and     byte [kbd_flags], 11111101b      ; ctrl off.
  99           jmp     .CAD_off
 100
 101      .alt_up:
 102           and     byte [kbd_flags], 11111011b      ; alt off.
 103           jmp     .CAD_off
 104
 105      .CAD_off:
 106           test    byte [kbd_flags], 01000000b
 107           jz      .CAD_is_off
 108           and     byte [kbd_flags], 10111111b      ; ctrl+alt+del bit off.
 109      .CAD_is_off:
 110           jmp     .end
 111
 112      ;----------------------------------------------;
 113      ;  a key was pressed, check for special keys   ;
 114      ;----------------------------------------------;
 115      .key_down:
 116           or      byte [kbd_flags], 10000000b
 117
 118      .shift:
 119           cmp     al, 42
 120           jnz     .check_rshift
 121           or      byte [kbd_flags], 00000001b
 122           jmp     .end
 123
 124      .check_rshift:
 125           cmp     al, 54
 126           jnz     .check_ctrl
 127           or      byte [kbd_flags], 00000001b
 128           jmp     .end
 129
 130      .check_ctrl:
 131           cmp     al, 29
 132           jnz     .check_alt
 133           or      byte [kbd_flags], 00000010b
 134           jmp     .end
 135
 136      .check_alt:
 137           cmp     al, 56
 138           jnz     .ctrl_alt_del
 139           or      byte [kbd_flags], 00000100b
 140           jmp     .end
 141
 142      .ctrl_alt_del:
 143           test    byte [kbd_flags], 00000110b         ; check for ctrl+alt
 144           jz      .check_caps
 145           cmp     al, 83                              ; check for delete
 146           jne     .check_caps
 147           or      byte [kbd_flags], 01000000b         ; ctrl+alt+del bit on.
 148
 149      ;-------------------------------------;
 150      ;  toggle caps, num and scroll lock   ;
 151      ;-------------------------------------;
 152      .check_caps:
 153           cmp     al, 58
 154           jnz     .check_num
 155           xor     byte [kbd_status], 4
 156           call    update_leds
 157           jmp     .end
 158
 159      .check_num:
 160           cmp     al, 69
 161           jnz     .check_scroll
 162           xor     byte [kbd_status], 2
 163           call    update_leds
 164           jmp     .end
 165
 166      .check_scroll:
 167           cmp     al, 70
 168           jnz     .end
 169           xor     byte [kbd_status], 1
 170           call    update_leds
 171           jmp     .end
 172
 173      ;-----------------------------------;
 174      ;  put the scancode in the buffer   ;
 175      ;-----------------------------------;
 176      .end:
 177           push    eax
 178           mov     edi, kbd_buffer
 179           xor     eax, eax
 180           mov     al, [kbd_head]
 181           add     edi, eax
 182           pop     eax
 183           stosb
 184           cmp     [kbd_head], 63                      ; if we reach the buffer
 185           jne     .cont1                              ; end, go back to 0.
 186           cmp     [kbd_tail], 0
 187           je      .error
 188           mov     [kbd_head], 0
 189           jmp     .quit
 190      .cont1:
 191           mov     ah, [kbd_tail]
 192           mov     al, [kbd_head]
 193           add     al, 1
 194           cmp     ah, al
 195           je      .error
 196           inc     [kbd_head]
 197           jmp     .quit
 198      .error:
 199           call    beep                                ; pc_speaker.inc
 200           mov     [kbd_head], 1                       ; fix it as good
 201           mov     [kbd_tail], 0                       ; as possible.. :S
 202      .quit:
 203           mov     al, 0x20
 204           out     0x20, al
 205           pop     eax
 206           ret
 207
 208
 209
 210 ;------------------------------;
 211 ;  Update the keyboard LED's   ;
 212 ;------------------------------;
 213 update_leds:
 214           push    ax
 215
 216           call    kbd_wait
 217           mov     al, 0xED
 218           out     0x60, al
 219           call    kbd_wait
 220           mov     al, [kbd_status]
 221           out     0x60, al
 222           call    kbd_wait
 223
 224           pop     ax
 225           ret
 226
 227
 228
 229 ;------------------;
 230 ;  keyboard wait   ;
 231 ;------------------;
 232 kbd_wait:
 233           jmp     $+2
 234           in      al, 0x64
 235           test    al, 1
 236           jz      .ok
 237           jmp     $+2
 238           in      al, 0x60
 239           jmp     kbd_wait
 240      .ok:
 241           test    al, 2
 242           jnz     kbd_wait
 243           ret
 244
 245
 246
 247 ;-------------------------------------------------------;
 248 ;  BOS INT to get a char.                               ;
 249 ;          out: ah = scan code,      al = ascii         ;
 250 ;               bh = flag-byte,      bl = led-byte      ;
 251 ;-------------------------------------------------------;
 252 getc:
 253           push    esi
 254
 255      .no_new:
 256           mov     al, [kbd_head]
 257           mov     ah, [kbd_tail]
 258           cmp     ah, 63
 259           jne     .check2
 260           cmp     al, 0
 261           je      .no_new
 262           mov     [kbd_tail], 0
 263           jmp     .done_check
 264      .check2:
 265           mov     bl, ah
 266           inc     bl
 267           cmp     bl, al
 268           je      .no_new
 269           inc     [kbd_tail]
 270      .done_check:
 271
 272           mov     esi, kbd_buffer
 273           movzx   eax, [kbd_tail]
 274           add     esi, eax
 275           mov     ah, byte [esi]                      ; ah = scancode
 276           movzx   esi, byte [esi]                     ; esi = scancode
 277
 278      ;------------------;
 279      ;  some checks..   ;
 280      ;------------------;
 281           cmp     ah, 0xFA
 282           je      .no_new
 283           cmp     ah, 0xE0
 284           je      .no_new
 285           cmp     ah, 0xE1
 286           je      .no_new
 287           test    ah, 0x80
 288           jnz     .no_new
 289
 290      ;--------------------------------;
 291      ;  check for caps, shift & alt   ;
 292      ;--------------------------------;
 293           test    [kbd_status], 00000100b
 294           jnz     .caps
 295           test    [kbd_flags], 00000001b
 296           jnz     .shift
 297
 298      ;------------------;
 299      ;  normal keymap   ;
 300      ;------------------;
 301           mov     al, [esi+keymap]                    ; scancode + keymap = ascii
 302           jmp     .end
 303
 304      ;--------------------;
 305      ;  capslock keymap   ;
 306      ;--------------------;
 307      .caps:
 308           test    [kbd_flags], 00000001b
 309           jnz     .caps_and_shift
 310
 311           mov     al, [esi+keymap_caps]
 312           jmp     .end
 313
 314      ;--------------------------;
 315      ;  caps and shift keymap   ;
 316      ;--------------------------;
 317      .caps_and_shift:
 318           mov     al, [esi+keymap_caps_shift]
 319           jmp     .end
 320
 321      ;-----------------;
 322      ;  shift keymap   ;
 323      ;-----------------;
 324      .shift:
 325           mov     al, [esi+keymap_shift]
 326           jmp     .end
 327
 328      ;---------------------------;
 329      ;  set registers and exit   ;
 330      ;---------------------------;
 331      .end:
 332           mov     bl, [kbd_status]
 333           mov     bh, [kbd_flags]
 334
 335           pop     esi
 336           ret
 337
 338
 339 ;------------------------------;
 340 ;  "press any key to..."       ;
 341 ;------------------------------;
 342 wait_key:
 343           push    eax
 344           push    ebx
 345           push    esi
 346
 347      .no_new:
 348           mov     al, [kbd_head]
 349           mov     ah, [kbd_tail]
 350           cmp     ah, 63
 351           jne     .check2
 352           cmp     al, 0
 353           je      .no_new
 354           mov     [kbd_tail], 0
 355           jmp     .done_check
 356      .check2:
 357           mov     bl, ah
 358           inc     bl
 359           cmp     bl, al
 360           je      .no_new
 361           inc     [kbd_tail]
 362      .done_check:
 363
 364           mov     esi, kbd_buffer
 365           movzx   eax, [kbd_tail]
 366           add     esi, eax
 367           mov     ah, byte [esi]                      ; ah = scancode
 368           cmp     ah, 0xFA                            ; check for some stuff..
 369           je      .no_new
 370           cmp     ah, 0xE0
 371           je      .no_new
 372           cmp     ah, 0xE1
 373           je      .no_new
 374           test    ah, 0x80
 375           jnz     .no_new
 376
 377           pop     esi
 378           pop     ebx
 379           pop     eax
 380           ret