25 lines
505 B
ArmAsm
25 lines
505 B
ArmAsm
;;; -*- Mode: asm; indent-tabs-mode: t; tab-width: 8 -*-
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;;Move length bytes from A_start address to lenght bytes starting at B_start.
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.proc memcpy
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.include "mem.inc"
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LDY #$00
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loop:
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LDA (B_start), Y
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STA (A_start), Y
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INY
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BEQ y_overflow
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change_length:
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DEC length
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BNE loop
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DEC length +1
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BPL loop
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RTS
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y_overflow:
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;; Y is now 0
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INC B_start + 1
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INC A_start + 1
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jmp change_length
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.endproc
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