title: How are const char and char pointers represented in memory in STM32
body: <p>How does MCU now that the string a variable is pointing on is in data memory or in program memory?<br>
  What does compiler do when I'm casting a <code>const char *</code> to <code>char *</code> (e.g. when calling <code>strlen</code> function)?<br>
  Can <code>char *</code> be used as a <code>char *</code> and <code>const char *</code> without any performance loss?</p>