Implemented some basic libc functions and a text console

libc/string/memchr.c

@@ -0,0 +1,14 @@
+#include <stddef.h>
+
+const void *memchr(const void *ptr, int value, size_t num) {
+    const unsigned char *buf = ptr;
+    unsigned char val = value;
+
+    for (size_t i = 0; i < num; i++) {
+        if (buf[i] == val) {
+            return (void *)(buf + i);
+        }
+    }
+
+    return NULL;
+}