2 ; Ullrich von Bassewitz, 2002-12-20
4 ; Common functions of the joystick API.
10 .interruptor joy_irq ; Export as IRQ handler
12 .include "joy-kernel.inc"
13 .include "joy-error.inc"
16 ;----------------------------------------------------------------------------
21 _joy_drv: .res 2 ; Pointer to driver
23 _joy_masks: .res .sizeof(JOY_HDR::MASKS)
25 ; Jump table for the driver functions.
28 joy_install: jmp $0000
29 joy_uninstall: jmp $0000
32 joy_irq: .byte $60, $00, $00 ; RTS plus two dummy bytes
34 ; Driver header signature
36 joy_sig: .byte $6A, $6F, $79, JOY_API_VERSION ; "joy", version
40 ;----------------------------------------------------------------------------
41 ; unsigned char __fastcall__ joy_install (void* driver);
42 ; /* Install the driver once it is loaded */
51 ; Check the driver signature
53 ldy #.sizeof(joy_sig)-1
62 ldy #JOY_HDR::MASKS + .sizeof(JOY_HDR::MASKS) - 1
63 ldx #.sizeof(JOY_HDR::MASKS)-1
70 ; Copy the jump vectors
74 @L2: inx ; Skip the JMP opcode
75 jsr copy ; Copy one byte
76 jsr copy ; Copy one byte
77 cpy #(JOY_HDR::JUMPTAB + .sizeof(JOY_HDR::JUMPTAB))
80 jsr joy_install ; Call driver install routine
82 bne @L3 ; Bail out if install had errors
84 ; Install the IRQ vector if the driver needs it. A/X contains the error code
85 ; from joy_install, so don't use it.
87 ldy joy_irq+2 ; Check high byte of IRQ vector
88 beq @L3 ; Jump if vector invalid
90 sty joy_irq ; Activate IRQ routine
93 ; Driver signature invalid
96 lda #JOY_ERR_INV_DRIVER
100 ; Copy one byte from the jump vectors
104 set: sta joy_vectors,x
108 ;----------------------------------------------------------------------------
109 ; unsigned char __fastcall__ joy_uninstall (void);
110 ; /* Uninstall the currently loaded driver. Note: This call does not free
111 ; * allocated memory.
115 lda #$60 ; RTS opcode
116 sta joy_irq ; Disable IRQ entry point
118 jsr joy_uninstall ; Call the driver routine
120 joy_clear_ptr: ; External entry point
123 sta _joy_drv+1 ; Clear the driver pointer