diff options
Diffstat (limited to 'at91lib')
| -rw-r--r-- | at91lib/utility/string.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/at91lib/utility/string.c b/at91lib/utility/string.c new file mode 100644 index 0000000..6c2af0d --- /dev/null +++ b/at91lib/utility/string.c @@ -0,0 +1,239 @@ +/* ----------------------------------------------------------------------------
+ * 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;
+}
+
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