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Fixed the break stuff
git-svn-id: svn://svn.cc65.org/cc65/trunk@1593 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz
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@ -6,8 +6,8 @@
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;
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.export _set_brk, _reset_brk
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.destructor _reset_brk
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.export _brk_a, _brk_x, _brk_y, _brk_sr, _brk_pc
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.import brk_jmp
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.include "plus4.inc"
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@ -19,11 +19,11 @@ _brk_y: .res 1
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_brk_sr: .res 1
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_brk_pc: .res 2
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oldvec: .res 2 ; Old vector
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oldvec: .res 2 ; Old vector
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.data
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uservec: jmp $FFFF ; Patched at runtime
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uservec: jmp $FFFF ; Patched at runtime
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.code
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@ -32,21 +32,12 @@ uservec: jmp $FFFF ; Patched at runtime
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.proc _set_brk
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sta uservec+1
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stx uservec+2 ; Set the user vector
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stx uservec+2 ; Set the user vector
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lda oldvec
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ora oldvec+1 ; Did we save the vector already?
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bne L1 ; Jump if we installed the handler already
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lda BRKVec
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sta oldvec
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lda BRKVec+1
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sta oldvec+1 ; Save the old vector
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L1: lda #<brk_handler ; Set the break vector to our routine
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ldx #>brk_handler
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sta BRKVec
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stx BRKVec+1
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lda #<brk_handler ; Set the break vector to our routine
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sta brk_jmp+1
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lda #>brk_handler
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sta brk_jmp+2
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rts
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.endproc
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@ -55,26 +46,20 @@ L1: lda #<brk_handler ; Set the break vector to our routine
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; Reset the break vector
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.proc _reset_brk
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lda oldvec
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ldx oldvec+1
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beq @L9 ; Jump if vector not installed
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sta BRKVec
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stx BRKVec+1
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lda #$00
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sta oldvec ; Clear the old vector
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stx oldvec+1
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@L9: rts
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lda #$00
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sta brk_jmp+1
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sta brk_jmp+2 ; Reset the vector
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rts
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.endproc
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; Break handler, called if a break occurs
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; Break handler, called if a break occurs. Note: Y is not on the stack!
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.proc brk_handler
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pla
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sta _brk_y
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sty _brk_y
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pla
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sta _brk_x
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pla
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@ -5,7 +5,9 @@
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;
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.export _exit
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.import initlib, donelib
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.export brk_jmp
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.import condes, initlib, donelib
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.import push0, _main, zerobss
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.import __IRQFUNC_TABLE__, __IRQFUNC_COUNT__
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@ -13,6 +15,11 @@
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.include "plus4.inc"
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; ------------------------------------------------------------------------
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; Constants
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IRQInd = $500 ; JMP $0000 - used as indirect IRQ vector
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; ------------------------------------------------------------------------
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; Place the startup code in a special segment to cope with the quirks of
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; plus/4 banking.
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@ -77,17 +84,44 @@ L1: lda sp,x
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jsr initlib
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; If we have IRQ functions, chain our stub into the IRQ vector
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lda #<__IRQFUNC_COUNT__
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beq NoIRQ1
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lda IRQVec
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ldx IRQVec+1
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sta IRQInd+1
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stx IRQInd+2
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lda #<IRQStub
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ldx #>IRQStub
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sei
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sta IRQVec
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stx IRQVec+1
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cli
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; Pass an empty command line
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jsr push0 ; argc
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NoIRQ1: jsr push0 ; argc
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jsr push0 ; argv
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ldy #4 ; Argument size
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jsr _main ; call the users code
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; Call module destructors. This is also the _exit entry.
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; Back from main (this is also the _exit entry). Reset the IRQ vector if
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; we chained it.
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_exit: jsr donelib ; Run module destructors
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_exit: lda #<__IRQFUNC_COUNT__
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beq NoIRQ2
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lda IRQInd+1
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ldx IRQInd+2
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sei
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sta IRQVec
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stx IRQVec+1
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cli
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; Run module destructors.
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NoIRQ2: jsr donelib ; Run module destructors
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; Restore system stuff
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@ -118,29 +152,65 @@ IRQ: pha
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pha
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tsx ; Get the stack pointer
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lda $0103,x ; Get the saved status register
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tax
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lda #>irqret ; Push new return address
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tax ; Save for later
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and #$10 ; Test for BRK bit
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bne dobreak
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lda #>irq_ret ; Push new return address
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pha
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lda #<irqret
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lda #<irq_ret
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pha
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txa
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pha
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sta ENABLE_ROM ; Switch to ROM
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jmp ($FFFE) ; Jump to kernal irq handler
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irqret: sta ENABLE_RAM ; Switch back to RAM
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irq_ret:
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sta ENABLE_RAM ; Switch back to RAM
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pla
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tax
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pla
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rti
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dobreak:
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lda brk_jmp+2 ; Check high byte of address
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beq nohandler
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jmp brk_jmp ; Jump to the handler
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; No break handler installed, jump to ROM
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nohandler:
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tya
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pha ; ROM handler expects Y on stack
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sta ENABLE_ROM
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jmp (BRKVec) ; Jump indirect to the break vector
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; ------------------------------------------------------------------------
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; Stub for the IRQ chain. Is used only if there are IRQs defined. Needed in
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; low memory because of the banking.
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.segment "LOWCODE"
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IRQStub:
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cld ; Just to be sure
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sta ENABLE_RAM ; Switch to RAM
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ldy #<(__IRQFUNC_COUNT__*2)
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lda #<__IRQFUNC_TABLE__
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ldx #>__IRQFUNC_TABLE__
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jsr condes ; Call the IRQ functions
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sta ENABLE_ROM
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jmp IRQInd ; Jump to the saved IRQ vector
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; ------------------------------------------------------------------------
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; Data
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.data
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zpsave: .res zpspace
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zpsave: .res zpspace
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; BRK handling
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brk_jmp: jmp $0000
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.bss
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spsave: .res 1
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spsave: .res 1
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@ -70,7 +70,7 @@ TED_RAMSEL = $FF3F
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; ---------------------------------------------------------------------------
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; RAM/ROM selection addresses
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ENABLE_ROM = $FF3E
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ENABLE_RAM = $FF3F
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ENABLE_ROM = TED_ROMSEL
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ENABLE_RAM = TED_RAMSEL
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