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1976d6cd32
All but one joystick drivers didn't use IRQs. Espsecially when the joystick driver kernel was the only .interruptor this meant quite some unnecessary overhead because it pulled in the whole IRQ infrastructure. I was told that the one driver using IRQs (the DXS/HIT-4 Player joystick driver for the C64) can be reworked to not do it. Until this is done that driver is defunct.
107 lines
2.5 KiB
ArmAsm
107 lines
2.5 KiB
ArmAsm
;
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; Ullrich von Bassewitz, 2002-12-20
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;
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; Common functions of the joystick API.
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;
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.import joy_libref
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.importzp ptr1
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.include "joy-kernel.inc"
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.include "joy-error.inc"
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;----------------------------------------------------------------------------
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; Variables
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.bss
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_joy_drv: .res 2 ; Pointer to driver
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; Jump table for the driver functions.
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.data
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joy_vectors:
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joy_install: jmp $0000
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joy_uninstall: jmp $0000
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joy_count: jmp $0000
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joy_read: jmp $0000
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; Driver header signature
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.rodata
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joy_sig: .byte $6A, $6F, $79, JOY_API_VERSION ; "joy", version
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.code
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;----------------------------------------------------------------------------
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; unsigned char __fastcall__ joy_install (void* driver);
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; /* Install the driver once it is loaded */
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_joy_install:
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sta _joy_drv
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sta ptr1
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stx _joy_drv+1
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stx ptr1+1
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; Check the driver signature
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ldy #.sizeof(joy_sig)-1
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@L0: lda (ptr1),y
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cmp joy_sig,y
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bne inv_drv
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dey
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bpl @L0
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; Set the library reference
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ldy #JOY_HDR::LIBREF
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lda #<joy_libref
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sta (ptr1),y
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iny
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lda #>joy_libref
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sta (ptr1),y
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; Copy the jump vectors
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ldy #JOY_HDR::JUMPTAB
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ldx #0
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@L1: inx ; Skip the JMP opcode
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jsr copy ; Copy one byte
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jsr copy ; Copy one byte
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cpy #(JOY_HDR::JUMPTAB + .sizeof(JOY_HDR::JUMPTAB))
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bne @L1
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jmp joy_install ; Call driver install routine
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; Driver signature invalid
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inv_drv:
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lda #JOY_ERR_INV_DRIVER
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ldx #0
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rts
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; Copy one byte from the jump vectors
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copy: lda (ptr1),y
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iny
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sta joy_vectors,x
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inx
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rts
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;----------------------------------------------------------------------------
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; unsigned char joy_uninstall (void);
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; /* Uninstall the currently loaded driver. Note: This call does not free
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; ** allocated memory.
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; */
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_joy_uninstall:
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jsr joy_uninstall ; Call the driver routine
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_joy_clear_ptr: ; External entry point
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lda #0
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sta _joy_drv
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sta _joy_drv+1 ; Clear the driver pointer
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tax ; Return zero
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rts
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