41 lines
764 B
ArmAsm
41 lines
764 B
ArmAsm
.define Mon
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.sect .text
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.sect .rom
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.sect .data
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.sect .bss
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.sect .text
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! This subroutine performs some monitor calls.
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! The exit call just resets the hardware_stackpointer so
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! this routine will return to the operating system.
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! The close call just returns a zero.
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! The ioctl call just pops its arguments and returns a zero.
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! The write routine is a real one.
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Mon:
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cpx #1
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bne 1f ! exit
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ldx STACK ! load stackpointer
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dex
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dex ! adjust stackpointer
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txs ! set stackpointer
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rts
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1: cpx #4
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bne 1f
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jmp Mwrite
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1: cpx #6 ! facked
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bne 1f ! close
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lda #0
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tax ! return zero
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rts
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1: cpx #54
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jsr Pop ! pop first argument (fildes)
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jsr Pop ! pop second argument (request)
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jsr Pop ! pop third argument (argp)
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lda #0
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tax ! return zero
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rts
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