I've been developing using the Arduino plattform for years and I really love it. Now I am working on something that would require the speed and ROM/RAM-size a Cortex CPU would offer.
I recently buyed a Teensy3.1 board that I really like. But I just noticed that the bootloader on that second Chip is not open or free what would be neccessary to me.
Unfortunately I have no clue when it comes to writing an own bootloader. I think I understand what they are doing and how they work basically but I do not feel that I could write one myself.
So I am looking for a solution that could either be a free Bootloader that I can install to the K20 (M4) Proessor and cutting of the secondary Chip or another developement board that uses a 32Bit ARM CPU with either an open bootloader or an integrated bootloader that can be used also for small commercial projects.
The very and golden best would be something that brings an Arduino IDE Plugin but I would also use something else (Eclipse with Plugin for Example).
Many thanks in Advance