cc65/libsrc/mouse/mouse-kernel.s

194 lines
5.5 KiB
ArmAsm

;
; Ullrich von Bassewitz, 2003-12-28, 2009-09-26
;
; Common functions of the mouse driver API.
;
.import return0, popsreg, incsp2, mouse_libref
.importzp sreg, ptr1, tmp1, tmp2
.interruptor mouse_irq ; Export as IRQ handler
.include "mouse-kernel.inc"
;----------------------------------------------------------------------------
; Variables
.bss
_mouse_drv: .res 2 ; Pointer to driver
_mouse_hidden: .res 1 ; Mouse visibility flag
; Jump table for the driver functions.
.data
mouse_vectors:
mouse_install: jmp return0
mouse_uninstall:jmp return0
mouse_hide: jmp return0
mouse_show: jmp return0
mouse_setbox: jmp return0
mouse_getbox: jmp return0
mouse_move: jmp return0
mouse_buttons: jmp return0
mouse_pos: jmp return0
mouse_info: jmp return0
mouse_ioctl: jmp return0
mouse_irq: .byte $60, $00, $00 ; RTS plus two dummy bytes
mouse_flags: .byte $00
; Driver header signature
.rodata
mouse_sig: .byte $6d, $6f, $75, MOUSE_API_VERSION ; "mou", version
.code
;----------------------------------------------------------------------------
; unsigned char __fastcall__ mouse_install (const struct mouse_callbacks* c,
; void* driver);
; /* Install an already loaded driver. Returns an error code. */
_mouse_install:
sta _mouse_drv
sta ptr1
stx _mouse_drv+1
stx ptr1+1
; Check the driver signature
ldy #.sizeof(mouse_sig)-1
@L0: lda (ptr1),y
cmp mouse_sig,y
bne inv_drv
dey
bpl @L0
; Set the library reference
ldy #MOUSE_HDR::LIBREF
lda #<mouse_libref
sta (ptr1),y
iny
lda #>mouse_libref
sta (ptr1),y
; Reset flags
lda #1
sta _mouse_hidden
; Copy the jump vectors
ldy #MOUSE_HDR::JUMPTAB
ldx #0
@L1: inx ; Skip the JMP opcode
jsr copyjv ; Copy one byte
jsr copyjv ; Copy one byte
cpy #(MOUSE_HDR::JUMPTAB + .sizeof(MOUSE_HDR::JUMPTAB))
bne @L1
; Copy the flags byte. It is located directly behind the jump vectors, so Y
; is already correct when we come here. To save code, we use copyjv - crude
; but effective.
jsr copyjv
; Copy the callback vectors into the driver space
jsr popsreg
ldy #(MOUSE_HDR::CALLBACKS + .sizeof(MOUSE_HDR::CALLBACKS) - 1)
sty tmp2
ldy #.sizeof(MOUSE_CALLBACKS)-1
sty tmp1
@L2: jsr copycb
ldy tmp1
jsr copycb
dec tmp2 ; Skip opcode byte
ldy tmp1
bpl @L2
; Install the IRQ vector if the driver needs it
bit mouse_flags ; Test MOUSE_FLAG_EARLY_IRQ
bvc @L3 ; Jump if no interrupts at this time
jsr install_irq ; Activate IRQ routine
; Call driver install routine and check for errors
@L3: jsr mouse_install
tay ; Test error code
bne uninstall_irq ; Jump on error
; No errors on INSTALL. If the driver needs late IRQs, enable them now. Be
; careful not to use A/X since these registers contain the error code from
; INSTALL.
bit mouse_flags ; Test MOUSE_FLAG_LATE_IRQ
bpl Exit ; Jump if vector not needed
install_irq:
ldy #$4C ; Jump opcode
sty mouse_irq ; Activate IRQ routine
Exit: rts
; Uninstall IRQ vector if install routine had errors. A/X may contain the
; error code from mouse_install, so don't use it.
uninstall_irq:
ldy #$60 ; RTS opcode
sty mouse_irq ; Disable IRQ entry point
rts
; Driver signature invalid. One word is still on the stack
inv_drv:
lda #MOUSE_ERR_INV_DRIVER
ldx #0
jmp incsp2
; Copy one byte from the jump vectors
copyjv: lda (ptr1),y
sta mouse_vectors,x
iny
inx
rts
; Copy one byte from the callback vectors
copycb: lda (sreg),y
dec tmp1
ldy tmp2
sta (ptr1),y
dec tmp2
rts
;----------------------------------------------------------------------------
; unsigned char mouse_uninstall (void);
; /* Uninstall the currently loaded driver. Returns an error code. */
_mouse_uninstall:
; Depending on the late/early IRQ flag, we will disable IRQs before or after
; calling the driver mouse_uninstall routine.
bit mouse_flags ; Test MOUSE_FLAG_LATE_IRQ
bpl @L1 ; Don't disable interrupts now
jsr uninstall_irq ; Disable driver interrupts
@L1: jsr mouse_uninstall ; Call driver routine
; We don't check the flag a second time here, since disabling IRQs twice,
; or disabling them if they weren't enabled will do no harm, and the missing
; check will save a few bytes.
jsr uninstall_irq ; Disable driver interrupts
_mouse_clear_ptr: ; External entry point
lda #0
sta _mouse_drv
sta _mouse_drv+1 ; Clear the driver pointer
tax
rts ; Return zero