I am breaking my head the last few days over how you should extract the firmware from a USB device I searched all over the internet but I could not find a straight forward way to do it. Just to clarify I am trying to do this over the USB connection it self but if this isn't possible then that is just fine. I found some things about flashrom online but I don't really understand how it works and I don't know if it is capable of flashing / reading USB firmware ( I mean USB sticks and other peripherals)

Any help would be very much appreciated


  • what kind of device it is? Did you open it and look at the components inside? Does the manufacturer provide firmware updates?
    – Igor Skochinsky
    Mar 3, 2018 at 20:56
  • The device is a USB stick for some reason I can't find out what microcontroller it has inside but I think it is phison but as I said the provided tool from phison can't find the stick and even programs like chipgenius can't see what controller it is so I am not certain Mar 3, 2018 at 21:06

4 Answers 4


Sorry that I do not have enough reps to comment. So writing this as an answer instead. The answers to these two questions seem to be be relevant to what you are asking as well. Have a look at them :

How do I extract a copy of an unknown firmware from a hardware device?

How to dump flash memory with SPI? (I know its SPI but some of the answers still could be relevant to your situation)


If it has a Cypress FX3 then it will double enumerate in Device Manager when you plug in the device, if that helps. The firmware is loaded FROM the driver and then the device will enumerate again.

It seems there are many usb packet sniffing tools, software or hardware.


Usually there's some way to switch the usb drive into programming mode. Then usb drive is being shown as some new usb device, to which a flasher program can connect and upload/download the firmware. In most cases switching to this programming mode requires to connect specific pins on the usb drive board. Or it automatically switches to the programming mode when usb drive firmware gets corrupted.


hope this helps


With regards


  • 2
    write a bit more. Maybe add the command how to use it? Apr 12, 2018 at 12:53
  • flashrom only handles SPI flash chips. it won't handle NAND flash or know how to extract embedded USB controller firmware.
    – Igor Skochinsky
    Apr 12, 2018 at 14:23

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