I know you are all dying to know how my progress has been going on the Raspberry Pi Android port. Well, it's coming along.
The Raspberry Pi currently uses a 3.1.9 ARM Linux kernel. The version of Android I decided to port over uses the 3.0.8 ARM kernel. To patch the 3.1.9 ARM kernel with Android, I had to go a circuitous route.
It would have been pretty easy if there were patches already out there that were JUST Android patches. I couldn't find any. I'm sure there is a way, using Git, to isolate the Android patches from the Git Android repository, but I haven't spent enough time playing with Git to do it. So, I went the old fashioned way.
To create my own isolated Android patch, I first needed to find an Android running on a 3.x.x version of the kernel. Ice Cream Sandwich is running against a 3.0.8 kernel (at the time I did this post) so that is where I started. The trick was to not include any ARM patches with the isolated Android patch because I needed to keep all of the Raspberry Pi ARM changes in tact.
So, starting with an x86 3.0.8 Android kernel I found, I created a patch from stock x86 3.0.8 to Android x86 3.0.8. That gave me an isolated Android patch. Then I applied that isolated Android patch to the 3.1.9 Raspberry Pi kernel. That took my Raspberry Pi kernel to an Android kernel.
Now I need to make the modifications to the Ice Cream Sandwich Android to make it a Headless Ice Cream Sandwich (in the shape of an Android, of course.)
Why x86? Well, that's a good question.
In order to get a clean isolated Android patch I needed to start with something that I could:
a) get a good clean stock kernel for, and
b) if there were unnecessary changes to the architecture or driver files they wouldn't affect and ARM system.
I could have attempted an ARM 3.x.x kernel but it's pretty hard to find an ARM kernel (of the 3.x.x revision) with an matching ARM kernel with Android that you would have confidence that the ARM portion is all the same. At least the x86 stuff is fairly well known and consistent.
Stay tuned, more to come!