Disable memtest

src/kern.c

@@ -62,7 +62,8 @@ void kernel_main(multiboot_info* mbt, uint32_t magic)
     int o=0;
     int j=5/o;
     serial_hexword(j);
-    test_mem();
+    //test_mem();
+    serial_writechar('\n');
 
     // PCI
     checkAllBuses();