stm32f4discovery limitations?

#1

Given the scarcity of Axoloti Core boards at the moment, I'm considering using the stm32f4discovery board for a project.
What are the limitations/possibilities with that?
If I remember correctly, audio input is not available on it, but can you get MIDI in/out?
If so, how? (gpio pins...?)
I would want to control a stepper motor with midi commands.
Also, where can I find information about how to modify/upload the firmware on stm32f4discovery?

#2

No audio input, no sdcard, no ground loop break, no sdram, no usb host, no wide range DC power input, and some gpio's are occupied by other things. DIN Midi can be added with a few components:
https://groups.google.com/forum/#!topic/axoloti-users/ZA8tUhE6E_c
Also check the restrictions of the STMicro evaluation board license:
http://www.st.com/st-web-ui/static/active/en/resource/legal/legal_agreement/license_agreement/EvaluationProductLicenseAgreement.pdf
Understand that my efforts are focused on Axoloti Core.