git.sur5r.net Git - cc65/blob - libsrc/mouse/mouse-kernel.s

   1 ;
   2 ; Ullrich von Bassewitz, 2003-12-28
   3 ;
   4 ; Common functions of the mouse driver API.
   5 ;
   6
   7         .import         return0
   8         .importzp       ptr1
   9
  10         .include        "mouse-kernel.inc"
  11
  12
  13
  14 ;----------------------------------------------------------------------------
  15 ; Variables
  16
  17
  18 .bss
  19 _mouse_drv:     .res    2               ; Pointer to driver
  20
  21 ; Jump table for the driver functions.
  22 .data
  23 mouse_vectors:
  24 mouse_install:  jmp     return0
  25 mouse_uninstall:jmp     return0
  26 mouse_hide:     jmp     return0
  27 mouse_show:     jmp     return0
  28 mouse_box:      jmp     return0
  29 mouse_move:     jmp     return0
  30 mouse_buttons:  jmp     return0
  31 mouse_pos:      jmp     return0
  32 mouse_info:     jmp     return0
  33
  34 ; Driver header signature
  35 .rodata
  36 mouse_sig:      .byte   $6d, $6f, $75, MOUSE_API_VERSION    ; "mou", version
  37
  38
  39 ;----------------------------------------------------------------------------
  40 ; unsigned char __fastcall__ mouse_install (void* driver);
  41 ; /* Install an already loaded driver. Returns an error code. */
  42
  43
  44
  45 _mouse_install:
  46         sta     _mouse_drv
  47         sta     ptr1
  48         stx     _mouse_drv+1
  49         stx     ptr1+1
  50
  51 ; Check the driver signature
  52
  53         ldy     #.sizeof(mouse_sig)-1
  54 @L0:    lda     (ptr1),y
  55         cmp     mouse_sig,y
  56         bne     inv_drv
  57         dey
  58         bpl     @L0
  59
  60 ; Copy the jump vectors
  61
  62         ldy     #MOUSE_HDR::JUMPTAB
  63         ldx     #0
  64 @L1:    inx                             ; Skip the JMP opcode
  65         jsr     copy                    ; Copy one byte
  66         jsr     copy                    ; Copy one byte
  67         cpy     #(MOUSE_HDR::JUMPTAB + .sizeof(MOUSE_HDR::JUMPTAB))
  68         bne     @L1
  69
  70         jmp     mouse_install           ; Call driver install routine
  71
  72 ; Driver signature invalid
  73
  74 inv_drv:
  75         lda     #MOUSE_ERR_INV_DRIVER
  76         ldx     #0
  77         rts
  78
  79 ; Copy one byte from the jump vectors
  80
  81 copy:   lda     (ptr1),y
  82         sta     mouse_vectors,x
  83         iny
  84         inx
  85         rts
  86
  87 ;----------------------------------------------------------------------------
  88 ; unsigned char __fastcall__ mouse_uninstall (void);
  89 ; /* Uninstall the currently loaded driver. Returns an error code. */
  90
  91 _mouse_uninstall:
  92         jsr     mouse_uninstall         ; Call driver routine
  93
  94 mouse_clear_ptr:                        ; External entry point
  95         lda     #0
  96         sta     _mouse_drv
  97         sta     _mouse_drv+1            ; Clear the driver pointer
  98
  99         tax
 100         rts                             ; Return zero
 101