Refactor parallel comms a bit

stdlib.c

@@ -1,3 +1,6 @@
+#include <stdint.h>
+#include <stdlib.h>
+
 int getchar() {
     register char c asm("al");
     asm volatile("movb $0x00, %%ah\n\t"
@@ -23,3 +26,20 @@ int puts(const char* s) {
     }
     return 0;
 }
+
+void* memcpy(void* dest, const void* src, size_t n) {
+    uint8_t* d = dest;
+    const uint8_t* s = src;
+    for (int i = 0; i < n; i++) {
+        d[i] = s[i];
+    }
+    return dest;
+}
+
+void* memset(void* ptr, int val, size_t len) {
+    uint8_t* p = ptr;
+    while (len--) {
+        *p++ = val;
+    }
+    return ptr;
+}