/* Copyright (c) 2006, Carlos Lamas based on libc/pmstring/strncpy_P.S which is Copyright (c) 2002, Marek Michalkiewicz All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the copyright holders nor the names of contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* $Id$ */ #if !defined(__AVR_TINY__) #include "macros.inc" #define dest_b1 r25 #define dest_b0 r24 #define src_b3 r23 #define src_b2 r22 #define src_b1 r21 #define src_b0 r20 #define len_b1 r19 #define len_b0 r18 #if !defined(__DOXYGEN__) .text .global _U(strncpy_PF) .type _U(strncpy_PF), @function _U(strncpy_PF): X_movw ZL, src_b0 LPM_R0_ZPLUS_INIT src_b2 X_movw XL, dest_b0 .L_strncpy_PF_loop: subi len_b0, lo8(1) sbci len_b1, hi8(1) brcs .L_strncpy_PF_done LPM_R0_ZPLUS_NEXT src_b2 st X+, r0 tst r0 brne .L_strncpy_PF_loop ; store null characters up to the end of dest ; as the glibc manual says: ; This behavior is rarely useful, but it is specified by the ISO C standard. rjmp .L_strncpy_PF_clr_start .L_strncpy_PF_clr_loop: st X+, __zero_reg__ .L_strncpy_PF_clr_start: subi len_b0, lo8(1) sbci len_b1, hi8(1) brcc .L_strncpy_PF_clr_loop .L_strncpy_PF_done: LPM_R0_ZPLUS_FINI src_b2 ; return dest (unchanged) ret .L_strncpy_PF_end: .size _U(strncpy_PF), .L_strncpy_PF_end - _U(strncpy_PF) #endif /* not __DOXYGEN__ */ #endif /* !defined(__AVR_TINY__) */