Openess of source code/drivers android phones

How open is the source code of android phones? I cannot think of a way that manufacturers ca开发者_如何学Cn close their drivers, because they have to conform to the GPLv2 as the License of the Linux kernel states. Or do they use write a large part in user space code, where they can choose their own licence?

The information I'm trying to get here is: How difficult is it to get a "cheap" smartphone (htc wildfire-s) and run Linux on top of it full featured. What I mean is every hardware feature is easily accesible without having to implement your own drivers and reverse engineer the device (assuming that the device is rooted).

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HTC has the developers area:

http://htcdev.com/devcenter

The kernel sources for the HTC wildfire you can also download there:

http://htcdev.com/devcenter/downloads

Note that not all the functionality is included in the kernel. To add functionality to your system you also have to install basic programs like a shell.

The Android system image already contains all necesary programs to run your system and som Android stuff which is not needed for a Linux-only system.

As an alternative you can have a look in the android source and remove all the unwanted programs from your custom android build.

http://source.android.com/source/initializing.html

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I think I found my answer at last. A lot of firmware of a lot of android phones is delivered binary only. Which makes it less open. If I want to run GNU/Linux on top of a stock phone I run in a lot of those issues. See Richard Stallmans article on how free android is: Is Android really free software?

There is also a project Replicant which tries to create a free (FSF definition of free) android based stack.