I was wondering if it was possible to boot just from the usd card without uboot? I see everyone using uboot, but i am looking to create my own bootloader so that I can use baremetal style programming. I currently use the rpi for development, for which i simply rewrite the kernal.img file with the one that I create. I would like to do something like this if possible to the usd card for the beagle board. The reasoning for this is that I have a bootloader written for many devices that uses a specific command structure that I would like to maintain.
Well, it depends on how you look at it. The answer is no.
The reason is that what you want to do is to write your own version of UBoot. Without UBoot the DDR and all the voltages are not setup. So you have to include all that in your version of Uboot. Now, if you want to call it something else, then that is certainly an option. But, the functions still must be there if you expect to run any of your code.
Think of UBoot as a bunch of bare metal code that provides a nice debug interface and can also load Linux.
Gerald