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  1. /*
  2.  * Copyright (c) 2001-2004 Jakub Jermar
  3.  * Copyright (c) 2008 Jiri Svoboda
  4.  * All rights reserved.
  5.  *
  6.  * Redistribution and use in source and binary forms, with or without
  7.  * modification, are permitted provided that the following conditions
  8.  * are met:
  9.  *
  10.  * - Redistributions of source code must retain the above copyright
  11.  *   notice, this list of conditions and the following disclaimer.
  12.  * - Redistributions in binary form must reproduce the above copyright
  13.  *   notice, this list of conditions and the following disclaimer in the
  14.  *   documentation and/or other materials provided with the distribution.
  15.  * - The name of the author may not be used to endorse or promote products
  16.  *   derived from this software without specific prior written permission.
  17.  *
  18.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28.  */
  29.  
  30. /** @addtogroup generic
  31.  * @{
  32.  */
  33.  
  34. /**
  35.  * @file
  36.  * @brief   Memory string operations.
  37.  *
  38.  * This file provides architecture independent functions to manipulate blocks of
  39.  * memory. These functions are optimized as much as generic functions of this
  40.  * type can be. However, architectures are free to provide even more optimized
  41.  * versions of these functions.
  42.  */
  43.  
  44. #include <memstr.h>
  45. #include <arch/types.h>
  46. #include <align.h>
  47.  
  48. /** Copy block of memory.
  49.  *
  50.  * Copy cnt bytes from src address to dst address.  The copying is done
  51.  * word-by-word and then byte-by-byte.  The source and destination memory areas
  52.  * cannot overlap.
  53.  *
  54.  * @param src       Source address to copy from.
  55.  * @param dst       Destination address to copy to.
  56.  * @param cnt       Number of bytes to copy.
  57.  *
  58.  * @return      Destination address.
  59.  */
  60. void *_memcpy(void *dst, const void *src, size_t cnt)
  61. {
  62.     unsigned int i, j;
  63.    
  64.     if (ALIGN_UP((uintptr_t) src, sizeof(unative_t)) != (uintptr_t) src ||
  65.         ALIGN_UP((uintptr_t) dst, sizeof(unative_t)) != (uintptr_t) dst) {
  66.         for (i = 0; i < cnt; i++)
  67.             ((uint8_t *) dst)[i] = ((uint8_t *) src)[i];
  68.     } else {
  69.         for (i = 0; i < cnt / sizeof(unative_t); i++)
  70.             ((unative_t *) dst)[i] = ((unative_t *) src)[i];
  71.        
  72.         for (j = 0; j < cnt % sizeof(unative_t); j++)
  73.             ((uint8_t *)(((unative_t *) dst) + i))[j] =
  74.                 ((uint8_t *)(((unative_t *) src) + i))[j];
  75.     }
  76.        
  77.     return (char *) dst;
  78. }
  79.  
  80. /** Move memory block with possible overlapping.
  81.  *
  82.  * Copy cnt bytes from src address to dst address. The source and destination
  83.  * memory areas may overlap.
  84.  *
  85.  * @param src       Source address to copy from.
  86.  * @param dst       Destination address to copy to.
  87.  * @param cnt       Number of bytes to copy.
  88.  *
  89.  * @return      Destination address.
  90.  */
  91. void *memmove(void *dst, const void *src, size_t n)
  92. {
  93.     const uint8_t *sp;
  94.     uint8_t *dp;
  95.  
  96.     /* Nothing to do? */
  97.     if (src == dst)
  98.         return dst;
  99.  
  100.     /* Non-overlapping? */
  101.     if (dst >= src + n || src >= dst + n) {
  102.         return memcpy(dst, src, n);
  103.     }
  104.  
  105.     /* Which direction? */
  106.     if (src > dst) {
  107.         /* Forwards. */
  108.         sp = src;
  109.         dp = dst;
  110.  
  111.         while (n-- != 0)
  112.             *dp++ = *sp++;
  113.     } else {
  114.         /* Backwards. */
  115.         sp = src + (n - 1);
  116.         dp = dst + (n - 1);
  117.  
  118.         while (n-- != 0)
  119.             *dp-- = *sp--;
  120.     }
  121.  
  122.     return dst;
  123. }
  124.  
  125. /** Fill block of memory
  126.  *
  127.  * Fill cnt bytes at dst address with the value x.  The filling is done
  128.  * byte-by-byte.
  129.  *
  130.  * @param dst       Destination address to fill.
  131.  * @param cnt       Number of bytes to fill.
  132.  * @param x     Value to fill.
  133.  *
  134.  */
  135. void _memsetb(void *dst, size_t cnt, uint8_t x)
  136. {
  137.     unsigned int i;
  138.     uint8_t *p = (uint8_t *) dst;
  139.    
  140.     for (i = 0; i < cnt; i++)
  141.         p[i] = x;
  142. }
  143.  
  144. /** Fill block of memory.
  145.  *
  146.  * Fill cnt words at dst address with the value x.  The filling is done
  147.  * word-by-word.
  148.  *
  149.  * @param dst       Destination address to fill.
  150.  * @param cnt       Number of words to fill.
  151.  * @param x     Value to fill.
  152.  *
  153.  */
  154. void _memsetw(void *dst, size_t cnt, uint16_t x)
  155. {
  156.     unsigned int i;
  157.     uint16_t *p = (uint16_t *) dst;
  158.    
  159.     for (i = 0; i < cnt; i++)
  160.         p[i] = x;  
  161. }
  162.  
  163. /** @}
  164.  */
  165.