thanks again for your help. Please let me know if my summary below matches what you did to burn a mellanox nic with secure_fw to a different psid:
1. You needed to use the MTUSB-1 device with a connection directly to the nic to issue commands via the I2C protocol/interface. Can you describe exactly how you made this connection? ex. did your nic have just the 3 holes? if so, how did you physically connect the MTUSB-1 device? Do you have any pics of the MTUSB-1 device with the cable and how it connects to the nic?
2. Once connected, you were able to use normal flint commands to burn the nic with an image with a different psid. Do you recall the parameters? ex. did you pass the allow_psid_change parameter? or was it something else that allowed the new image file to be burned?
3. rebooted and .....magic! a 100G nic is turned into a functioning 200G nic. I have some sw that can test to make sure that it is actually performing at 200Gbps rates and 400Gbps bidirectionally.
I have been able to do the above directly using just flint from either linux or vmware without the need for MTUSB-1 or I2C. The difference is that the nics that I have been able to do this with were the cx-5 without any secure_fw. the cx6 and cx6-dx seem to be enabled with secure_fw.
Thanks for your help! if I am able to get this working, I may be able to return the favor and send a matching 200G nic so that you can have the matching pair!
this worked for me:
flint -d /dev/mst/mt4099_pciconf0 -i image.bin -allow_psid_change burn