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64 lines
1.5 KiB
ArmAsm
64 lines
1.5 KiB
ArmAsm
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.export Start, _exit
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.import initlib, donelib, callmain
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.import push0, _main, zerobss, copydata
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; Linker generated symbols
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.import __RAM_START__, __RAM_SIZE__
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.include "zeropage.inc"
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.include "gamate.inc"
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Start:
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; setup the CPU and System-IRQ
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; Initialize CPU
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sei
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cld
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ldx #0
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stx ZP_IRQ_CTRL ; disable calling cartridge IRQ/NMI handler
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; Setup stack and memory mapping
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;ldx #$FF ; Stack top ($01FF)
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dex
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txs
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; Clear the BSS data
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jsr zerobss
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; Copy the .data segment to RAM
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jsr copydata
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; setup the stack
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lda #<(__RAM_START__+__RAM_SIZE__)
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sta sp
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lda #>(__RAM_START__+__RAM_SIZE__)
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sta sp + 1
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; Call module constructors
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jsr initlib
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lda #1
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sta ZP_IRQ_CTRL ; enable calling cartridge IRQ/NMI handler
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cli ; allow IRQ only after constructors have run
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; Pass an empty command line
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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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_exit:
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jsr donelib ; Run module destructors
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; reset (start over)
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jmp Start
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.export initmainargs
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initmainargs:
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rts
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