memxxx function changes to be Misra compliant

board/libc.h

@@ -6,32 +6,36 @@ void delay(int a) {
 }
 
 void *memset(void *str, int c, unsigned int n) {
-  unsigned int i;
-  for (i = 0; i < n; i++) {
-    *((uint8_t*)str) = c;
-    ++str;
+  uint8_t *s = str;
+  for (unsigned int i = 0; i < n; i++) {
+    *s = c;
+    s++;
   }
   return str;
 }
 
 void *memcpy(void *dest, const void *src, unsigned int n) {
-  unsigned int i;
-  // TODO: make not slow
-  for (i = 0; i < n; i++) {
-    ((uint8_t*)dest)[i] = *(uint8_t*)src;
-    ++src;
+  uint8_t *d = dest;
+  const uint8_t *s = src;
+  for (unsigned int i = 0; i < n; i++) {
+    *d = *s;
+    d++;
+    s++;
   }
   return dest;
 }
 
 int memcmp(const void * ptr1, const void * ptr2, unsigned int num) {
-  unsigned int i;
   int ret = 0;
-  for (i = 0; i < num; i++) {
-    if ( ((uint8_t*)ptr1)[i] != ((uint8_t*)ptr2)[i] ) {
+  const uint8_t *p1 = ptr1;
+  const uint8_t *p2 = ptr2;
+  for (unsigned int i = 0; i < num; i++) {
+    if (*p1 != *p2) {
       ret = -1;
       break;
     }
+    p1++;
+    p2++;
   }
   return ret;
 }