Originally Posted by noo_too_droid
To quote shrike (I hope that's alright)
So I've read this but what would that mean in terms of developement? If Android didn't have to be a separate branch of Linux, would it be easier to spread ROMs to all the different phones?
I'm not a dev, but in my understanding the biggest hurdle for porting ROMS is device drivers. It is relatively easy to port a ROM from the HTC One X to the HTC Rezound, because they are made by the same manufacturer, have the same system-on-a-chip manufacturer (Qualcomm) and have a similar stock kernel based on different versions of HTC Sense.
But porting a ROM from, let's say a Samsung Galaxy III is nigh impossible, because it uses a different system-on-a-chip exclusive to Samsung phones and its stock kernel is based on TouchWiz. And even though Android is based on Linux, each of the phone manufacturers have slightly different ways of organizing system files that set the various system options. So a kernel patch that works on one device probably won't work on another. (kernel level features such as GPU overclocking, two-way call recording etc. rely on these system setting files).
Even among phones made by the same company, you may have hardware differences such as different camera technologies, different screen resolutions, etc. that make porting harder.
That's why cyanogenmod, AOKP and MIUI are so valuable and appreciated, because they organize porting of a ROM that, as far as the kernel and GUI are concerned, vary little between devices. However those projects still have to rely on what manufacturers choose to release as open source to develop hardware device drivers to port the ROM to each device.
And then you have the problem of, what level of Android is officially supported by the manufacturer? The Droid Incredible 2, for example, is still waiting for an official ICS release it may never get, which means running Jellybean as it is meant to be run is that much harder. It's hard enough on the Rezound, where we have official ICS kernel source.
That's why I give lots of kudos to people who take custom ROMs like BAMF paradigm, paranoid android and the like that were developed for other devices and port them to the Rezound. And mega kudos to people like chad who can port/re-factor underlying hardware code originally developed for another device to work on the Rezound. We're talking crazy wizard-level stuff like memory management, camera, hardware graphics optimization (Project Butter).