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cc65/libsrc/supervision/crt0.s

82 lines
1.8 KiB
ArmAsm

;
; Startup code for cc65 (supervision version)
;
.export _exit
.export __STARTUP__ : absolute = 1 ; Mark as startup
.import _main
.import initlib, donelib, copydata
.import zerobss
.import __RAM_START__, __RAM_SIZE__ ; Linker generated
.import __STACKSIZE__ ; Linker generated
.include "zeropage.inc"
.include "supervision.inc"
.export _sv_irq_timer_counter, _sv_irq_dma_counter
.export _sv_nmi_counter
.bss
_sv_irq_dma_counter: .byte 0
_sv_irq_timer_counter: .byte 0
_sv_nmi_counter: .byte 0
.code
reset:
jsr zerobss
; initialize data
jsr copydata
lda #>(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)
sta sp+1 ; Set argument stack ptr
stz sp ; #<(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)
jsr initlib
jsr _main
_exit: jsr donelib
exit: jmp exit
.proc irq
pha
lda sv_irq_source
and #SV_IRQ_REQUEST_TIMER
beq not_timer
lda sv_timer_quit
inc _sv_irq_timer_counter
not_timer:
lda sv_irq_source
and #SV_IRQ_REQUEST_DMA
beq not_dma
lda sv_dma_quit
inc _sv_irq_dma_counter
not_dma:
pla
rti
.endproc
.proc nmi
inc _sv_nmi_counter
rti
.endproc
; removing this segment gives only a warning
.segment "FFF0"
.proc reset32kcode
lda #(6<<5)
sta sv_bank
; now the 32kbyte image can reside in the top of 64kbyte, 128kbyte roms
jmp reset
.endproc
.segment "VECTOR"
.word nmi
.word reset32kcode
.word irq