Hardware i.MX50 Boot mode

The information in the following linked thread may lead to a way to get the K5-Paperwhite (i.MX508) into USB-HID downloader mode:
https://community.freescale.com/message/271552#271552

That process may require a patched U-Boot (if the lab126 U-Boot isn't already patched).

Something similar may be possible for the DX(G) (i.MX31 if I recall correctly).