====== Firmware reset ======

In case a complete new firmware image (U-Boot, linux kernel, root filesystem) is to be installed, but the the rescue mode cannot be enabled because the DIP switches are not accessible, a workaround is to invalidate the master boot record (MBR) of the eMMC flash:

  * using Linux
<code bash>dd if=/dev/zero of=/dev/mmcblk0 bs=1024 count=4</code>

  * using U-Boot
<code>mw.b $loadaddr 0 1000; mmc write 0 $loadaddr 0 8</code>

Without the linux kernel booting the MFG-Tool can now connect to the system and install a new firmware image.