Build android system from source

I've recently purchased Samsung Galaxy Android phone after using Openmoko phone for 2 years.

One of the reasons for choosing Android was is that it's open sourced. I don't want to depend on phone 开发者_StackOverflow中文版maker to provide updates for my phone. I'd like to do it myself. Right now I'm in research stage if it's worth the time or not. So here are the questions:

1. I found some tutorials for building ROM images from source. They tell that Android build script will ask for make of the phone before building kernel. Does it mean that all the phone specific stuff is handled by the script or I will have to do some voodoo before I can flash it onto my phone?

2. Drivers. How are they handled? Are they included in the source as binaries and added automatically (question 1) or will I have to dissect old firmware to get them and put in my build? I realize that would mean some problems with module/kernel versions compatibility.

3. Is there is something I'm not aware of that would prevent me from building my custom firmware or make it very time-consuming?

I'm not afraid of installing SDK's and toolchains, after all I'm an Openmoko owner.

It's gonna be a little more complicated than that.

1. On any consumer Android phones I've seen, the user doesn't have root access to the OS. So step one, would be finding an exploit to get root.
2. Even after you get root, all consumer Android phones "lock" the bootloader to prevent unauthorized OS images from being booted.
3. The Android OpenSource project only contains device drivers for a small number of phones (Google dev phones, possibly the Nexus One?). For other phones, the drivers are proprietary binaries that the manufacturer loads on the phone. They generally aren't available separately.

Even with all of those obstacles, some enterprising smart guys have managed to create custom "ROM's" that blend the OpenSource release with drivers ripped OEM install on the phone, etc. CyanogenMod is one of the best known and is available for several different Android devices, but unfortunately the Samsung Galaxy does not currently appear to be one of the device supported by Cyanogen.

I found an old link here to a guide to getting root on the Galaxy and loading a custom ROM on it, but unfortunately the ROM they link to doesn't seem to be actively maintained anymore. It might be worth doing some more exhaustive google searches to see if you can find anyone doing active development on the Galaxy.