This is the first code that will be run after execution begins. <code>TwlProcess9</code> uses this to put ARM7 in a loop (TWL), and to set the <code>POSTFLG</code> and branch to more copied code (GBA). This doesn't seem to start execution by itself.
You cannot return to this region. Reading uninitialized data in this 32-byte region leads to both screens displaying solid greed and the CPU locking up.