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add memcopy16

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Matthias@Dell 2023-12-27 16:55:40 +01:00
parent 25d0fcfb90
commit fc0dba6c9c
1 changed files with 44 additions and 7 deletions
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51
programs/memcopy.s65
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@ -3,15 +3,16 @@ INCLUDE_MEMCOPY = 1
.include "system.h65"
.export memcopy
.export memcopy,memcopy16
.code
;********************************************************************************
; @function Copy a block of memory to a different address
; @param ARG0-1: Source address
; @param ARG2-3: Target address
; @param y: Number of bytes to copy
;********************************************************************************
;;********************************************************************************
;; @function Copy a block of memory to a different address
;; @param ARG0-1: Source address
;; @param ARG2-3: Target address
;; @param Y: Number of bytes to copy
;; @modifies: A,Y
;;********************************************************************************
.proc memcopy
cpy #0
beq @rts
@ -24,5 +25,41 @@ INCLUDE_MEMCOPY = 1
@rts:
rts
.endproc
;;********************************************************************************
;; @function Copy a block of memory to a different address
;; @param ARG0-1: Source address
;; @param ARG2-3: Target address
;; @param ARG5-6: Number of bytes to copy (LE)
;; @modifies: A,Y
;;********************************************************************************
.proc memcopy16
lda ARG6
beq @last_page ; no full page
ldy #$ff
bra @copy_byte
@next_page: ; y is 0
lda ARG6
beq @rts ; done
inc ARG1
inc ARG3
dec ARG6
beq @last_page
ldy #$ff
@copy_byte:
lda (ARG0),y
sta (ARG2),y
@dec_y:
dey
beq @next_page
bra @copy_byte
@last_page:
ldy ARG5
dey
bra @copy_byte
@rts:
rts
.endproc
.endif ; guard