UBoot recovery for am335 via xmodem

For the programming of the AM335x we take use of the X-Modem, so there is no use of external Hardware except a PC with a com-port. You also need a Linux distribution for example the Virtual Machine for Application Development with Debian Jessie

1. Installation
   • installing the Debian package lrzsz
     • sudo apt-get install lrzsz
   • Standard password for VM is devel
2. Programing
   • Download required files here:
   • The MLO.byteswap and the uBoot.img are normal uBoot files
   • If you use the Virtual Machine, then don’t import the serial Port because this can cause issues
   • 
   • check which ttyUSBX port is needed for programing $ cd /dev && ls
   • Please change the ttyUSBX in the following code to the one you need
   • Navigate into the folder where the programing files are located
   • Power on the board and check if it prints "C" on the serial monitor
     • sx -kb u-boot-spl.bin < /dev/ttyUSBX > /dev/ttyUSBX
   • Wait for the message "Trying to boot from UART" on the serial monitor
     • sx -kb u-boot.img < /dev/ttyUSBX > /dev/ttyUSBX
   • Wait for uBoot to boot, if the output stops with "**No partition table - mmc 1 **" you can go on (can take a while)
     • echo 'loady ${loadaddr}' > /dev/ttyUSBX
   • Wait for the message "Ready for binary (ymodem) download to 0x82000000 at 115200 bps..." on the serial monitor
     • sx MLO.byteswap < /dev/ttyUSBX > /dev/ttyUSBX
   • Wait untill the Serial Monitor confirms that the data is sent
     • echo 'sf probe; sf erase 0x0 0x20000; sf write ${loadaddr} 0x0 ${filesize};' > /dev/ttyUSBX
   • Wait for the acknowledge“
     • • SF: Detected S25FL216K with page size 256 Bytes, erase size 4 KiB, total 16 MiB
       • SF: 131072 bytes @ 0x0 Erased: OK
       • device 0 offset 0x0, size 0x6794
       • SF: 26516 bytes @ 0x0 Written: OK “
     • echo 'loady ${loadaddr}' > /dev/ttyUSBX
   • Ready for binary (ymode) download to 0x82000000 at 115200 bps...
     • sx u-boot.img < /dev/ttyUSBX > /dev/ttyUSBX
   • Wait till the Serial Monitor not the programing terminal confirms that the data is sent
     • echo 'sf probe; sf erase 0x20000 0xA0000; sf write ${loadaddr} 0x20000 ${filesize};' > /dev/ttyUSBX
   • Wait for the acknowledge “
     • • SF probe; sf erase 0x20000 0xA0000; sf write ${loadaddr} 0x20000 ${filesize};
       • SF: Detected S25FL216K with page size 256 Bytes, erase size 4 KiB, total 16 MiB
       • SF: 655360 bytes @ 0x20000 Erased: OK
       • device 0 offset 0x20000, size 0x60eec
       • SF: 397036 bytes @ 0x20000 Written: OK
     • echo "reset" > /dev/ttyUSBX