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/* Copyright (c) 2006, Carlos Lamas
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based on libc/pmstring/strnlen_P.S which is
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Copyright (c) 2005, Helmut Wallner
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based on libc/pmstring/strnlen.S which is
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Copyright (c) 2002, Marek Michalkiewicz
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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* Neither the name of the copyright holders nor the names of
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE. */
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/* $Id: strnlen_PF.S 2191 2010-11-05 13:45:57Z arcanum $ */
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#if !defined(__AVR_TINY__)
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/** \ingroup avr_pgmspace
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\fn size_t strnlen_PF(uint_farptr_t s, size_t len)
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\brief Determine the length of a fixed-size string
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The strnlen_PF() function is similar to strnlen(), except that \e s is a
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far pointer to a string in program space
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\param s A far pointer to the string in Flash
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\param len The maximum number of length to return
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\returns The strnlen_PF function returns strlen_P(\e s), if that is less
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than \e len, or \e len if there is no '\\0' character among the first \e
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len characters pointed to by \e s. The contents of RAMPZ SFR are
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undefined when the function returns */
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#if !defined(__DOXYGEN__)
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.global _U(strnlen_PF)
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.type _U(strnlen_PF), @function
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LPM_R0_ZPLUS_INIT src_b2
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LPM_R0_ZPLUS_NEXT src_b2
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brcc .L_strnlen_PF_loop
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; RAMPZ:Z points one character past the terminating NUL
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; return RAMPZ:Z - 1 - src = (-1 - src) + RAMPZ:Z = ~src + RAMPZ:Z
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X_movw src_b2, src_b0 ; size_t is 16 bits
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.size _U(strnlen_PF), .L_strnlen_PF_end - _U(strnlen_PF)
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#endif /* not __DOXYGEN__ */
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#endif /* !defined(__AVR_TINY__) */
added
removed
libc/pmstring/strnlen_PF.S
