I need to a board to be a USB peripheral and provide read/write to a flash or SD card. It must not mount as a drive or look like file sharing or use mass storage class driver on PC or mac. I am considering BeagleBone. What is quickest way?
Sounds like someone is trying to circumvent some admin and security controls. Just use an app that will let you connect to a serial port and transmit data. Write a bare metal app for the BB that takes the serial data and shoves it out to the SD card. Of course, you'll need a FAT32 lib on the BB as well to save your data as a file. Those are plentiful if you do a search. Just be warned, the serial connection isn't as fast as USB transfers. Also be warned that you'll most certainly lose your job as soon as you're caught doing this. Good luck...