Hi,
I would recommend customer to using Segger J-Link firmware to update FRDM-K64F board OpenSDA V2.
After that, the OpenSDA could works as J-Link tool, then customer could using to debug the code and program the board.
Below is how to enter into the Bootloader mode:
Enter Bootloader Mode
Disconnect all power, external circuits and USB cables.
Press and hold the button marked RESET (circled in picture)
Connect a USB cable as shown in the picture
The drive should mount named BOOTLOADER
The reset button can now be released
Wish it helps.
Have a great day,
Ma Hui
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