MatthiasQuintern/6502-OS
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

add memcopy16

Browse Source
This commit is contained in:
Matthias@Dell 2023-12-27 16:55:40 +01:00
parent 25d0fcfb90
commit fc0dba6c9c
1 changed files with 44 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
programs/memcopy.s65
View File

@ -3,15 +3,16 @@ INCLUDE_MEMCOPY = 1
.include "system.h65" .include "system.h65"
.export memcopy .export memcopy,memcopy16
.code .code
;******************************************************************************** ;;********************************************************************************
; @function Copy a block of memory to a different address ;; @function Copy a block of memory to a different address
; @param ARG0-1: Source address ;; @param ARG0-1: Source address
; @param ARG2-3: Target address ;; @param ARG2-3: Target address
; @param y: Number of bytes to copy ;; @param Y: Number of bytes to copy
;******************************************************************************** ;; @modifies: A,Y
;;********************************************************************************
.proc memcopy .proc memcopy
cpy #0 cpy #0
beq @rts beq @rts
@ -24,5 +25,41 @@ INCLUDE_MEMCOPY = 1
@rts: @rts:
rts rts
.endproc .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 .endif ; guard