Changed the mouse API: Introduced a new flag byte that contains information

[cc65] / libsrc / mouse / mouse-kernel.s

diff --git a/libsrc/mouse/mouse-kernel.s b/libsrc/mouse/mouse-kernel.s
index d568984a89be4d3250428e1e10dc4052e2211151..9a1fdf1f191e22e256c14fcbdfca551a3e9cf154 100644 (file)
--- a/libsrc/mouse/mouse-kernel.s
+++ b/libsrc/mouse/mouse-kernel.s
@@ -35,6 +35,7 @@ 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
@@ -77,6 +78,12 @@ _mouse_install:
         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
@@ -94,23 +101,34 @@ _mouse_install:
 
 ; Install the IRQ vector if the driver needs it
 
-        lda     mouse_irq+2             ; Check high byte of IRQ vector
-        beq     @L3                     ; Jump if vector invalid
-       lda     #$4C                    ; Jump opcode
-               sta     mouse_irq               ; Activate IRQ routine
+        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
-        beq     @L4                    ; Jump if no error
+        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.
 
-; Uninstall IRQ vector if install routine had errors. A/X contains the error
-; code from mouse_install, so don't use it.
+        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
-@L4:    rts
+        rts
 
 ; Driver signature invalid. One word is still on the stack
 
@@ -141,9 +159,7 @@ copycb: lda     (sreg),y
 ; /* Uninstall the currently loaded driver. Returns an error code. */
 
 _mouse_uninstall:
-       lda     #$60                    ; RTS opcode
-       sta     mouse_irq               ; Disable IRQ entry point
-
+       jsr     uninstall_irq           ; Disable driver interrupts
         jsr     mouse_uninstall         ; Call driver routine
 
 mouse_clear_ptr:                        ; External entry point