What forum sites would you recommend for platforms, internal software and hardware of mobile phones?

Question

Do it yourself

Tell me where you can talk about the innards of mobile phones of the pre-Android era. Interested in a thoughtful analysis of firmware, assemblers, operating systems and hardware.
One of the goals is to take a cell phone and sharpen it for yourself.

Answer 1

So far, I found it from the necessary ones on the Samsung firmware
forum.sgh.ru/topic45200.html