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https://github.com/cc65/cc65.git
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Correctly map out ROM when needed in the "phantom keys" workaround.
This commit is contained in:
Christian Groessler
parent
54be6de9bc
commit
6307815ada
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@ -66,15 +66,6 @@ CMOVEY: jmp $0000 ; Move the cursor to Y coord
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SCREEN_HEIGHT = 200
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SCREEN_WIDTH = 320
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;----------------------------------------------------------------------------
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; data segment
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.data
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chainIRQ:
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.byte $4c ; JMP opcode
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.word 0 ; pointer to ROM IRQ handler (will be set at runtime)
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;----------------------------------------------------------------------------
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; Global variables. The bounding box values are sorted so that they can be
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; written with the least effort in the SETBOX and GETBOX routines, so don't
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@ -103,6 +94,10 @@ Buttons: .res 1 ; Button mask
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old_key_count: .res 1
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; original IRQ vector
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old_irq: .res 2
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.rodata
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; Default values for above variables
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@ -158,20 +153,27 @@ INSTALL:
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; Initialize our IRQ magic
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lda IRQInd+1
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sta chainIRQ+1
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; remember ROM IRQ continuation address
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lda IRQInd+2
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sta chainIRQ+2
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sta old_irq+1
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lda IRQInd+1
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sta old_irq
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lda libref
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sta ptr3
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lda libref+1
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sta ptr3+1
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; set ROM IRQ continuation address to point to the provided routine
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ldy #2
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lda (ptr3),y
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sta IRQInd+1
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iny
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lda (ptr3),y
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sta IRQInd+2
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; set address of our IRQ callback routine
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; since it's called via "rts" we have to use "address-1"
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iny
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lda #<(callback-1)
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sta (ptr3),y
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@ -179,10 +181,16 @@ INSTALL:
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lda #>(callback-1)
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sta (ptr3),y
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iny
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lda #<(chainIRQ-1)
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; set ROM entry point vector
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; since it's called via "rts" we have to decrement it by one
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lda old_irq
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sec
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sbc #1
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sta (ptr3),y
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iny
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lda #>(chainIRQ-1)
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lda old_irq+1
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sbc #0
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sta (ptr3),y
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cli
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@ -197,10 +205,10 @@ INSTALL:
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; No return code required (the driver is removed from memory on return).
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UNINSTALL:
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lda chainIRQ+1
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lda old_irq
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sei
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sta IRQInd+1
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lda chainIRQ+2
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lda old_irq+1
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sta IRQInd+2
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cli
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@ -73,15 +73,6 @@ SCREEN_WIDTH = 320
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FIRE = $10
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.endenum
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;----------------------------------------------------------------------------
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; data segment
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.data
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chainIRQ:
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.byte $4c ; JMP opcode
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.word 0 ; pointer to ROM IRQ handler (will be set at runtime)
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;----------------------------------------------------------------------------
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; Global variables. The bounding box values are sorted so that they can be
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; written with the least effort in the SETBOX and GETBOX routines, so don't
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@ -108,6 +99,10 @@ Temp: .res 1
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old_key_count: .res 1
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; original IRQ vector
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old_irq: .res 2
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.rodata
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; Default values for above variables
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@ -163,20 +158,27 @@ INSTALL:
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; Initialize our IRQ magic
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lda IRQInd+1
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sta chainIRQ+1
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; remember ROM IRQ continuation address
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lda IRQInd+2
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sta chainIRQ+2
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sta old_irq+1
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lda IRQInd+1
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sta old_irq
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lda libref
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sta ptr3
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lda libref+1
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sta ptr3+1
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; set ROM IRQ continuation address to point to the provided routine
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ldy #2
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lda (ptr3),y
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sta IRQInd+1
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iny
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lda (ptr3),y
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sta IRQInd+2
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; set address of our IRQ callback routine
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; since it's called via "rts" we have to use "address-1"
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iny
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lda #<(callback-1)
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sta (ptr3),y
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@ -184,10 +186,16 @@ INSTALL:
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lda #>(callback-1)
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sta (ptr3),y
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iny
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lda #<(chainIRQ-1)
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; set ROM entry point vector
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; since it's called via "rts" we have to decrement it by one
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lda old_irq
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sec
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sbc #1
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sta (ptr3),y
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iny
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lda #>(chainIRQ-1)
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lda old_irq+1
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sbc #0
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sta (ptr3),y
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cli
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@ -202,10 +210,10 @@ INSTALL:
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; No return code required (the driver is removed from memory on return).
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UNINSTALL:
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lda chainIRQ+1
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lda old_irq
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sei
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sta IRQInd+1
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lda chainIRQ+2
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lda old_irq+1
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sta IRQInd+2
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cli
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@ -26,7 +26,7 @@ _pen_adjuster:
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.addr IRQStub2
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callback: ; callback into mouse driver after ROM IRQ handler has been run
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.addr $0000 ; (filled in by mouse driver)
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jmp_rom_hdlr: ; "trampoline" to jump to ROM IRQ handler
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jmp_rom_hdlr: ; original ROM indirect IRQ handler address
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.addr $0000 ; (filled in by mouse driver)
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@ -54,11 +54,17 @@ IRQStub2:
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lda #MMU_CFG_CC65 ; MMU configuration which will be active after the ROM handler returns
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pha
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; map out ROM
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ldy MMU_CR
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sta MMU_CR
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; push address of ROM handler on stack and jump to it
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lda jmp_rom_hdlr+1
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pha
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lda jmp_rom_hdlr
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pha
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sty MMU_CR ; map in ROM
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rts ; jump to ROM handler
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; our MMU configuration byte we pushed on the stack before (MMU_CFG_CC65) is now active
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