string: memcmp()

kernel-src/include/string.h

@@ -10,5 +10,6 @@ void *memcpy(void *dest, void *src, size_t size);
 void *memset(void *dest, unsigned long what, size_t size);
 int strcmp(const char *a, const char *b);
 int strncmp(const char *a, const char *b, size_t c);
+int memcmp(const void *a, const void *b, size_t s);
 
 #endif

kernel-src/lib/string.c

@@ -66,3 +66,14 @@ int strncmp(const char *a, const char *b, size_t c) {
 
         return diff;
 }
+
+int memcmp(const void *_a, const void *_b, size_t s) {
+	const uint8_t *a = _a;
+	const uint8_t *b = _b;
+	int diff = 0;
+
+	while (s-- && diff == 0)
+		diff += *a++ - *b++;
+
+	return diff;
+}