xv6-cs450/string.c
kaashoek 21a88fd487 checkpoint. booting second processor. stack is messed up, but thanks to cliff
and plan 9 code, at least boots and gets into C code.
2006-06-22 01:28:57 +00:00

60 lines
838 B
C

#include "types.h"
#include "defs.h"
void *
memcpy(void *dst, void *src, unsigned n)
{
char *d = (char *) dst;
char *s = (char *) src;
while(n-- > 0)
*d++ = *s++;
return dst;
}
void *
memset(void *dst, int c, unsigned n)
{
char *d = (char *) dst;
while(n-- > 0)
*d++ = c;
return dst;
}
int
memcmp(const void *v1, const void *v2, unsigned n)
{
const uint8_t *s1 = (const uint8_t *) v1;
const uint8_t *s2 = (const uint8_t *) v2;
while (n-- > 0) {
if (*s1 != *s2)
return (int) *s1 - (int) *s2;
s1++, s2++;
}
return 0;
}
void *
memmove(void *dst, const void *src, unsigned n)
{
const char *s;
char *d;
s = src;
d = dst;
if (s < d && s + n > d) {
s += n;
d += n;
while (n-- > 0)
*--d = *--s;
} else
while (n-- > 0)
*d++ = *s++;
return dst;
}