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- ; ----------------------------------------------------------------
- ; This file is released under the GPL v3 License
- ; Copyleft (k) 2008
- ; by Jose Rodriguez-Rosa (a.k.a. Boriel) <http://www.boriel.com>
- ; Use this file as a template to develop your own library file
- ; ----------------------------------------------------------------
- ; Emulates both memmove and memcpy C routines
- ; Blocks will safely copies if they overlap
- ; HL => Start of source block
- ; DE => Start of destiny block
- ; BC => Block length
- ;
- __MEMCPY:
- ;- PROC
- ;- LOCAL __MEMCPY2
- lda z80_l ;- push hl
- pha
- lda z80_h
- pha
- ;- add hl,bc
- ora z80_a ;- or a
- ;- sbc hl,de ; checks if DE > HL + BC
- pla ;- pop hl ; recovers HL. If Carry set => DE > HL
- sta z80_h
- pla
- sta z80_l
- ;- jr c, __MEMCPY2
- ;- ; Now checks if DE <= HL
- ;- sbc hl,de
- ;- add hl,de
- ;- jr nc, __MEMCPY2
- ;- dec bc
- lda z80_l ;- add hl,bc
- clc
- adc z80_c
- sta z80_l
- lda z80_h
- adc z80_b
- sta z80_h
- lda z80_e ;- ex de,hl
- ldx z80_l
- stx z80_e
- sta z80_l
- lda z80_d
- ldx z80_h
- stx z80_d
- sta z80_h
- lda z80_l ;- add hl,bc
- clc
- adc z80_c
- sta z80_l
- lda z80_h
- adc z80_b
- sta z80_h
- lda z80_e ;- ex de,hl
- ldx z80_l
- stx z80_e
- sta z80_l
- lda z80_d
- ldx z80_h
- stx z80_d
- sta z80_h
- inc z80_c ;- inc bc ; HL and DE point to the last byte position
- bne *+4
- inc z80_b
- ;- lddr ; Copies from end to beginning
- rts ;- ret
- __MEMCPY2:
- ldy #$00 ;- ldir
- ldx z80_b
- beq ldir_last_page
- ldir_loop:
- lda (z80_hl),y
- sta (z80_de),y
- iny
- bne ldir_loop
- inc z80_h
- inc z80_d
- dex
- bne ldir_loop
- ldir_last_page:
- lda z80_c
- beq ldir_end
- ldir_last_page_loop:
- lda (z80_hl),y
- sta (z80_de),y
- iny
- cpy z80_c
- bne ldir_last_page_loop
- ldir_end:
- stx z80_c
- stx z80_b
- tya
- clc
- adc z80_l
- sta z80_l
- bcc *+4
- inc z80_h
- tya
- clc
- adc z80_e
- sta z80_e
- bcc *+4
- inc z80_d
- rts ;- ret
- ;- ENDP
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