--- /dev/null
+#ifndef STRING_H_
+#define STRING_H_
+
+#include <stdlib.h>
+
+void memset(void *s, int c, size_t n);
+void memset16(void *s, int c, size_t n);
+
+void *memcpy(void *dest, const void *src, size_t n);
+void *memmove(void *dest, const void *src, size_t n);
+
+size_t strlen(const char *s);
+
+char *strchr(const char *s, int c);
+char *strrchr(const char *s, int c);
+
+char *strstr(const char *str, const char *substr);
+
+int strcmp(const char *s1, const char *s2);
+
+#endif /* STRING_H_ */