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at91lib: re-add utility/string.c from basic-dataflash-example

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Harald Welte 2011-07-30 19:31:17 +02:00
parent ef6648e27a
commit a6d24d323b
1 changed files with 239 additions and 0 deletions
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at91lib/utility/string.c Normal file
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/* ----------------------------------------------------------------------------
* ATMEL Microcontroller Software Support
* ----------------------------------------------------------------------------
* Copyright (c) 2008, Atmel Corporation
*
* 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 disclaimer below.
*
* Atmel's name may not be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
* ----------------------------------------------------------------------------
*/
//------------------------------------------------------------------------------
/// \unit
///
/// !Purpose
///
/// Implementation of several methods defined in string.h, for reducing the
/// memory footprint when using them (since the whole libc.o file gets included
/// even when using a single method).
///
/// !Usage
///
/// Add string.c to the list of files to compile for the project. This will
/// automatically replace standard libc methods by the custom ones.
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Headers
//------------------------------------------------------------------------------
#include <string.h>
//------------------------------------------------------------------------------
// Global Functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Copies data from a source buffer into a destination buffer. The two buffers
/// must NOT overlap. Returns the destination buffer.
/// \param pDestination Destination buffer.
/// \param pSource Source buffer.
/// \param num Number of bytes to copy.
//------------------------------------------------------------------------------
void * memcpy(void *pDestination, const void *pSource, size_t num)
{
unsigned char *pByteDestination;
unsigned char *pByteSource;
unsigned int *pAlignedSource = (unsigned int *) pSource;
unsigned int *pAlignedDestination = (unsigned int *) pDestination;
// If num is more than 4 bytes, and both dest. and source are aligned,
// then copy dwords
if ((((unsigned int) pAlignedDestination & 0x3) == 0)
&& (((unsigned int) pAlignedSource & 0x3) == 0)
&& (num >= 4)) {
while (num >= 4) {
*pAlignedDestination++ = *pAlignedSource++;
num -= 4;
}
}
// Copy remaining bytes
pByteDestination = (unsigned char *) pAlignedDestination;
pByteSource = (unsigned char *) pAlignedSource;
while (num--) {
*pByteDestination++ = *pByteSource++;
}
return pDestination;
}
//------------------------------------------------------------------------------
/// Fills a memory region with the given value. Returns a pointer to the
/// memory region.
/// \param pBuffer Pointer to the start of the memory region to fill
/// \param value Value to fill the region with
/// \param num Size to fill in bytes
//------------------------------------------------------------------------------
void * memset(void *pBuffer, int value, size_t num)
{
unsigned char *pByteDestination;
unsigned int *pAlignedDestination = (unsigned int *) pBuffer;
unsigned int alignedValue = (value << 24) | (value << 16) | (value << 8) | value;
// Set words if possible
if ((((unsigned int) pAlignedDestination & 0x3) == 0) && (num >= 4)) {
while (num >= 4) {
*pAlignedDestination++ = alignedValue;
num -= 4;
}
}
// Set remaining bytes
pByteDestination = (unsigned char *) pAlignedDestination;
while (num--) {
*pByteDestination++ = value;
}
return pBuffer;
}
//-----------------------------------------------------------------------------
/// Search a character in the given string.
/// Returns a pointer to the character location.
/// \param pString Pointer to the start of the string to search.
/// \param character The character to find.
//-----------------------------------------------------------------------------
char * strchr(const char *pString, int character)
{
char * p = (char *)pString;
char c = character & 0xFF;
while(*p != c) {
if (*p == 0) {
return 0;
}
p++;
}
return p;
}
//-----------------------------------------------------------------------------
/// Return the length of a given string
/// \param pString Pointer to the start of the string.
//-----------------------------------------------------------------------------
size_t strlen(const char *pString)
{
unsigned int length = 0;
while(*pString++ != 0) {
length++;
}
return length;
}
//-----------------------------------------------------------------------------
/// Search a character backword from the end of given string.
/// Returns a pointer to the character location.
/// \param pString Pointer to the start of the string to search.
/// \param character The character to find.
//-----------------------------------------------------------------------------
char * strrchr(const char *pString, int character)
{
char *p = 0;
while(*pString != 0) {
if (*pString++ == character) {
p = (char*)pString;
}
}
return p;
}
//-----------------------------------------------------------------------------
/// Copy from source string to destination string
/// Return a pointer to the destination string
/// \param pDestination Pointer to the destination string.
/// \param pSource Pointer to the source string.
//-----------------------------------------------------------------------------
char * strcpy(char *pDestination, const char *pSource)
{
char *pSaveDest = pDestination;
for(; (*pDestination = *pSource) != 0; ++pSource, ++pDestination);
return pSaveDest;
}
//-----------------------------------------------------------------------------
/// Compare the first specified bytes of 2 given strings
/// Return 0 if equals
/// Return >0 if 1st string > 2nd string
/// Return <0 if 1st string < 2nd string
/// \param pString1 Pointer to the start of the 1st string.
/// \param pString2 Pointer to the start of the 2nd string.
/// \param count Number of bytes that should be compared.
//-----------------------------------------------------------------------------
int strncmp(const char *pString1, const char *pString2, size_t count)
{
int r;
while(count) {
r = *pString1 - *pString2;
if (r == 0) {
if (*pString1 == 0) {
break;
}
pString1++;
pString2++;
count--;
continue;
}
return r;
}
return 0;
}
//-----------------------------------------------------------------------------
/// Copy the first number of bytes from source string to destination string
/// Return the pointer to the destination string.
/// \param pDestination Pointer to the start of destination string.
/// \param pSource Pointer to the start of the source string.
/// \param count Number of bytes that should be copied.
//-----------------------------------------------------------------------------
char * strncpy(char *pDestination, const char *pSource, size_t count)
{
char *pSaveDest = pDestination;
while (count) {
*pDestination = *pSource;
if (*pSource == 0) {
break;
}
pDestination++;
pSource++;
count--;
}
return pSaveDest;
}