[Samsung Galaxy Player 4.0, 5.0] hanthesolo:
Yes, this completely belongs in the dev section, especially since you seem to have enough ,motivation and kniw-how to be able to work on this project :).

This seems like a very interesting project, that would definitely be feasible, but Linux would have to replace android 100% (since heimdall/Odin flash to only the internal flash, and you would need ticreate a weird frankenstein-esque kernel to be able to boot it from anywhere else, although I suppose you could partition a micrlsd card and use that). I do not know enough in this particular field to be of much help, but if you do want any assistance, or have any questions, feel free to ask me or any other member of TeamSuperNova.

Welcome to the forums!

EDIT: My 2c on the project:

What you are setting out to do sounds like a very nice side project, that could be very a very nice addition to forums, and I have a few things I would just like for you to consider.

1. This is an aging device. We have a decent SOC, even though it is getting on in it's years, but I seriosuly doubt that it would be able to run Ubuntu natively well, even with full HW acceleration, and even if it does, we have only 512 MB for you to play around with. In comparison, the TF (dual core Tegra 2 +1 GB ram) has had native ubuntu for awhile now, and just got full HW acceleration. I tried it, and although the interface was smooth, everything took several seconds too long to complete, and overall it seemed like it would crawl to a stop (which it did a few times) the moment a few things started going. Our 1 GB of ram was enough, but only barely enough to give us some breathing room for browsing/light gaming.

2.The kernel. To get Ubuntu running natively, you will need to figure out how to create a linux kernel for Ubuntu, which is a LOT harder than just cut/pasting the needed modules and compiling. Most liikely you will need to start from scratch, and build your own kernel from the ground up, which requires a lot of kernel experience. Fortunately, we have several IT members on the forums such as daniel644 and Oisis which I am sure would be happy to help you whenever they have free time.

3.Time. Assuming that this will be a one-man job, you seriosuly need to think about how long this will take. Weeks? months? Years? I do not know your skill level and/or experience, but my prediction is that this will take about 6 months of hard work (assuming a few hours a day and sufficient support from the community) to see it to fruition. If you really are dedicated to this, I would suggest trying to form a dev team (like we did) of people who would be interested, and WORK. I don't just mean ballpark ideas until you like the way something sounds, but set goals for youselves, (eg. kernel booting with dmesg by xx date).

4. Bootloader. Our bootloaders are very finicky, unfortunately, unlike something like the TF, where you can overwrite the full bootloader partition, and you can just NVflash away and be done with it. If you make a mistake, write something to the wrong section, partition the wrong way, there is a very real chance that you will get into a hard-brick situation, from which you may not be able to get out of. At least our bootloader isn''t locked, so you don't need to worry about that.

I don't want to sound demotivational or depressing, but these are some real things you need to take into consideration. Again, if you have any questions, just pop me a PM whenever you want, and I will probably respond fairly quickly (as I normally browse xda in my spare time). Good luck, and may the bits be ever in your favor (sorry, sorry).