Implemented some basic libc functions and a text console

libc/string/memcmp.c

@@ -0,0 +1,8 @@
+#include <stddef.h>
+
+int memcmp(const void *vl, const void *vr, size_t n)
+{
+    const unsigned char *l=vl, *r=vr;
+    for (; n && *l == *r; n--, l++, r++);
+    return n ? *l-*r : 0;
+}