UART recovery boot

1. Make sure the BOOT mode is set to UART. 2. Connect to the debug UART with your computer and launch the serial terminal application

 picocom -b 115200 /dev/ttyUSB0 --send-cmd "sz -vv -X" --receive-cmd  "rz -vv  -X"

3. Start the board. When "CCCC" characters appear on terminal window, do:

 C-a C-s
 *** file: u-boot-spl.bin

4. Exit from picocom using C-a C-q, and relaunch picocom with

 picocom -b 115200 /dev/ttyUSB0 --send-cmd "sz -vv -Y" --receive-cmd  "rz -vv  -Y"

5. When "CCCC" characters appear on terminal window, do:

 C-a C-s
 *** file: u-boot.bin

6. Hitting any key to stop automatic boot, should present the U-Boot prompt.

Firsts steps with AM335x