cscg22-gearboy

CSCG 2022 Challenge 'Gearboy'
git clone https://git.sinitax.com/sinitax/cscg22-gearboy
Log | Files | Refs | sfeed.txt

memcpy.s (1627B)


      1;--------------------------------------------------------------------------
      2;  memcpy.s
      3;
      4;  Copyright (C) 2020, Sergey Belyashov
      5;  Copyright (c) 2021, Philipp Klaus Krause
      6;
      7;  This library is free software; you can redistribute it and/or modify it
      8;  under the terms of the GNU General Public License as published by the
      9;  Free Software Foundation; either version 2, or (at your option) any
     10;  later version.
     11;
     12;  This library is distributed in the hope that it will be useful,
     13;  but WITHOUT ANY WARRANTY; without even the implied warranty of
     14;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
     15;  GNU General Public License for more details.
     16;
     17;  You should have received a copy of the GNU General Public License 
     18;  along with this library; see the file COPYING. If not, write to the
     19;  Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
     20;   MA 02110-1301, USA.
     21;
     22;  As a special exception, if you link this library with other files,
     23;  some of which are compiled with SDCC, to produce an executable,
     24;  this library does not by itself cause the resulting executable to
     25;  be covered by the GNU General Public License. This exception does
     26;  not however invalidate any other reasons why the executable file
     27;   might be covered by the GNU General Public License.
     28;--------------------------------------------------------------------------
     29
     30        .area   _CODE
     31
     32	.globl _memcpy
     33	.globl ___memcpy
     34
     35; The Z80 has the ldir instruction, which is perfect for implementing memcpy().
     36_memcpy:
     37___memcpy:
     38	ex	de, hl
     39	pop	iy
     40	pop	bc
     41	ld	a, c
     42	or	a, b
     43	jr	Z, end
     44	push	de
     45	ldir
     46	pop	de
     47end:
     48	jp	(iy)
     49