emailler/client/ip65/copymem.s

57 lines
695 B
ArmAsm
Raw Normal View History

; utility routine to copy memory
.export copymem
.exportzp copy_src
.exportzp copy_dest
.segment "IP65ZP" : zeropage
; pointers for copying
copy_src: .res 2 ; source pointer
copy_dest: .res 2 ; destination pointer
.bss
end: .res 1
.code
;copy memory
;inputs:
; copy_src is address of buffer to copy from
; copy_dest is address of buffer to copy to
; AX = number of bytes to copy
;outputs: none
copymem:
sta end
ldy #0
cpx #0
beq @tail
: lda (copy_src),y
sta (copy_dest),y
iny
bne :-
inc copy_src+1 ;next page
inc copy_dest+1 ;next page
dex
bne :-
@tail:
lda end
beq @done
: lda (copy_src),y
sta (copy_dest),y
iny
cpy end
bne :-
@done:
rts