[Galaxy S Advance I9070 General] Paul L.:
KitKat? from Samsung? NEVER, Samsung is converting to the pain in the ass Apple was to Android at the start. Locking down phones to regions? Locking bootloaders? wut.

And anyway, as you said ST-Ericsson does not exist anymore. They had some code laying around, and that code is useful, but it's really, really messed up.

In example, the device has a Mali 400 GPU, same as a Samsung Galaxy S II (did anyone wonder why our device was initially based on Galaxy S II device tree?). The Mali 400 GPU has A LOT of source code, from ARM Holdings itself, (becauase Mali GPU is the standard GPU basis for ARM Cortex-A9 architecture), from other open source projects. But we must adapt anything from those sources to our device, and for that we need specifications, datasheets, data that points to specific electronic stuff on the motherboard of our device.

We could guess, but guessing it's not good, and takes more time, and we could damage the device on the way.

The ST-Ericsson Novathor U8500 is a dual-core ARM Cortex-A9 based and ARM-v7 instruction set compliant System-on-a-Chip. But compliant doesn't mean that it hasn't any propietary stuff from ST-Ericsson or even Samsung. If it was purely based on ST-Ericsson implmentation, we could had taken source from the ST-Ercisson Snowball development board and throw most of it to our device, but again, we don't have datasheets, specific motherboard electronic implementations, parts, codes, pins layous, etc described in papers or any document you could ever find on internet.

And about the Samsung support on devices with Android on it...

If you want to read, there is a higher tone explaination below, on spoilers. I'm warning you, this is not pointing to anyone, but things like that always interefere in one way or another to developing. I apologize if I used the "F" word too many times.

I bought a device, AS I OWN A HARDWARE and not the software (which IS OPEN SOURCE btw) that the device contains, I must be ABLE to MODIFY MY DEVICE.

In my interpretation, circunventing device security is not a concern for Samsung, it should not, because they do not own a device I have adquired. They own the "technology" inside it, but depends on the interpretation of what this "technology" means.

So, device security is not a concern when the user wants to unlock the device and do stuff with it, it is a concern when somebody else wants to, but since the device is mine and not theirs, and the could circunvent security locks without my approval, they are the ones infringing the laws. They should provide a device unlock, it must be difficult enough so people who doesn't know what the f*** are doing can't actually start the process. And after the process start, they should provide "We are not responsibles of what you are going to do to your device" and the warranty MUST BE BROKEN, and also, we shouldn't try to reset device modifications counter.

I put the below text in spoilers because you have to get the point.

Because, if we do, they are going to lock down everything like this. IF YOU DON'T KNOW WHAT ARE YOU DOING, JUST DON'T DO IT. DON'T TRY TO CIRCUNVENT DIGITAL LOCKINGS JUST BECAUSE YOU WANT TO INSTALL A BOOTANIMATION. DON'T RESET ANY COUNTER OF CUSTOM FLASHINGS, BECAUSE IF YOU BROKE YOUR DEVICE BY DOING THINGS YOU KNOW THAT WERE RISKY, THAT IS YOUR FU***** GUILT, NOT SAMSUNG ONE, AND OTHERS ARE PAYING BECAUSE YOU JUST FU***** WANTED A REFUND BECAUSE STUPID YOUR MISTAKE AND TL;DR'ING. WE TRY TO EXPLAIN WHAT YOU HAVE TO DO, WHAT COULD HAPPEN, THEY ALREADY EXPLAINED WHY DEVICE MODIFICATIONS BREAK THE WARRANTY. IF YOU BREAK SOMETHING, BLAME YOURSELF, START READING, AND DON'T BE SUCH A FU***** LAZY GUY/GAL.

It's like saying "I do not own the device, but I -Samsung- own everything the device contains software-wise, but not physically"

So, TL;DR our luck is limited, and we can't just do magic without sources, it's not that easy.