I'm a high level programmer and starting to know hardware stuffs and assembly. I'm just curious how do hardware programmers or maybe hackers know the specific address of a component like for example a bluetooth in a mobile phone. How can you read the value of the address where the bluetooth stores its frequency and perhaps change it?
I'm also a new arduino programmer and arduino lets you change/read the value of a component on depending on the pin you used. I'm sure that's how it works with other hardware too but what if you are just hacking a hardware without the description of the actual hardware like a mobile phone?