[Transformer TF300T Q&A, Help & Troubleshooting] bilange:
I never touched boot so far to tinker around Linux booting, for the simple reason we never use the recovery partition except to flash/nandroid backup (which I rarely do), plus it gave me with Android booting if I dont press the volume button on startup. As far as development went, I think this was a win/win situation, although lilstevie (the guy who did make Ubuntu boot natively on his TF101/200) told me to "never touch recovery, flash boot instead", he was most probably talking about deploying our custom OSes to the world to use.

Now i'm kinda lost as to why the regular Android boot is being shown up. Having 0 experience with the boot partition (which i thought was similar to recovery), i can't really help you. Maybe you should get on freenode into the #asus-transformer and ask around (Don't let the numbers of nicknames scare you, this is a low activity channel, but the most knowledgables people are hanging in there. Just be sure to do your homework (aka Google etc) before asking, you should be fine :) )

As a sidenote, you should probably use some (most?) of the kernel parameters used in /proc/cmdline from a live Android OS. Most specifically the "tegraboot=sdmmc gpt gpt_sector=..." part. This makes sure your kernel reads the partition table at the right (unusual) location instead of reading where ever it was on a regular system (the first 512 bytes of the drive? don't quote me on this). I suppose this doesn't prevent the kernel from booting, but it will make the SSD partitions visible from your OS.

Would that be a 'vanilla' 3.3.8? I'm asking because, in case you don't know, I think you can't have much success using the regular kernel from kernel.org, and hope it will detect all the devices (specifically touch, sensors, wifi, gps(?), etc). It will maybe boot (your guess is as good as mine), but it will surely lack a few things here and there. That's why there are a ton of devices specific github kernel code base here and there: it's basically a 'stock' kernel source code, with the constructor's additions to make their various devices work, with community enhancements on top of all that. I may be wrong on the following (if there are any veterans reading this, feel free to call me a noob and point me to the right direction), but if you try to compile ASUS' kernel source code for the TF300, funnily enough everything compiles silently UNTIL it gets to the Tegra parts where it gets noisy with over 9000 warnings all along (but it compiles). That led me to believe that 1) NVidia or ASUS are lousy coders :) and 2) They added (most likely) OR modified a bunch of code to the stock kernel tree to make it 100% functioning on their devices.

All that wall of text only to say that I assume that the broken fbcon issue is most probably due to either ASUS/NVidia additions to the kernel code, or a bug from the 'stock' kernel code, and i'm assuming it was fixed in later versions (which lacks device's constructor modifications then again).

--

Offtopic: it seems ASUS has released the kernel source code for TF300 for their JB update! Compile all the things!! :D (And hope fbcon as been fixed so I can see something out of the screen)