What complexities are involvod in writing a ROM for an android fone

This is a pretty open ended question.

I have a T-Mobile Touch and have some free time on my hands. So far as i understand im stuck with Android 1.5 and no sign of T-Mobile or Huawei releasing 开发者_Python百科a ROM using a more up-to-date version of the Android SDK.

Im asking what are the major complexities involved with making a ROM for this fone using a newer version of the Android SDK?

take a look at the http://forum.xda-developers.com/ and try to find your device there