I have a imx7dsabre board.
I set the BOOTMODE=01 MFG mode.
boot form sd 00100000.
the system can't enter usb download mode, but if I take out the sd card ，the mfg software can find my imx7dsabre board. then I insert the sd card，the usb download program works well.
my imx6slevk board set different mode is works well. Whether the imx7dsabre board has some problem.
Thanks & Best Regards!