linux/arch/arm/boot/compressed/string.c
Rob Herring 76df69806b ARM: boot: Add an implementation of strnlen for libfdt
Recent versions of libfdt add a dependency on strnlen. Copy the
implementation in lib/string.c here, so we can update libfdt.

Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Rob Herring <robh@kernel.org>
2016-02-11 19:43:47 -06:00

137 lines
2.0 KiB
C

/*
* arch/arm/boot/compressed/string.c
*
* Small subset of simple string routines
*/
#include <linux/string.h>
void *memcpy(void *__dest, __const void *__src, size_t __n)
{
int i = 0;
unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
for (i = __n >> 3; i > 0; i--) {
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
}
if (__n & 1 << 2) {
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
}
if (__n & 1 << 1) {
*d++ = *s++;
*d++ = *s++;
}
if (__n & 1)
*d++ = *s++;
return __dest;
}
void *memmove(void *__dest, __const void *__src, size_t count)
{
unsigned char *d = __dest;
const unsigned char *s = __src;
if (__dest == __src)
return __dest;
if (__dest < __src)
return memcpy(__dest, __src, count);
while (count--)
d[count] = s[count];
return __dest;
}
size_t strlen(const char *s)
{
const char *sc = s;
while (*sc != '\0')
sc++;
return sc - s;
}
size_t strnlen(const char *s, size_t count)
{
const char *sc;
for (sc = s; count-- && *sc != '\0'; ++sc)
/* nothing */;
return sc - s;
}
int memcmp(const void *cs, const void *ct, size_t count)
{
const unsigned char *su1 = cs, *su2 = ct, *end = su1 + count;
int res = 0;
while (su1 < end) {
res = *su1++ - *su2++;
if (res)
break;
}
return res;
}
int strcmp(const char *cs, const char *ct)
{
unsigned char c1, c2;
int res = 0;
do {
c1 = *cs++;
c2 = *ct++;
res = c1 - c2;
if (res)
break;
} while (c1);
return res;
}
void *memchr(const void *s, int c, size_t count)
{
const unsigned char *p = s;
while (count--)
if ((unsigned char)c == *p++)
return (void *)(p - 1);
return NULL;
}
char *strchr(const char *s, int c)
{
while (*s != (char)c)
if (*s++ == '\0')
return NULL;
return (char *)s;
}
#undef memset
void *memset(void *s, int c, size_t count)
{
char *xs = s;
while (count--)
*xs++ = c;
return s;
}
void __memzero(void *s, size_t count)
{
memset(s, 0, count);
}