Root Third-party ROM creation question

[JoeSchmoe007]

I am a software developer and would like some clarification on third party ROMs.

I understand these ROMs are custom/customized firmware/OS for the cell phone implemented by enthusiasts.

What I would like to know is how this firmware is created.

Do these guys run some kind of "disassembler" on standard firmware binaries, get the source code this way and then modify source code and compile it to binary again?

Do they get an "official" source code, modify it and compile it to binary again?

Or is there some other approach (messing with binaries directly? seems unfeasible)?

I am a bit concerned of using these ROMs because

1) possible bugs that can be introduced by changes that haven't been tested enough;

2) possibility for malicious code to be slipped in.

Has these 2 items been a real problem?

 

[jbdan]

There are inevitably bugs in all ROM's even the official builds from HTC/Verizon/Google. Some of the 3rd party ROMS are actually less buggy then the stock OS.

Sounds like you know a lot more than most here including me on compiling these. You might want to take a look on Cyanogen's website and some links they offer (github, etc...) as they openly post all their source code.

With the relative ease it takes to root and unroot the Inc and flash and backup ROM's, there isn't too much need for concern, just have some patience and due research before you begin