Updating the bootloader

You can update the bootloader with a USB drive. You may need to update the bootloader in rare cases when there is a new version of the bootloader or when you build your own bootloader.

Do not disconnect the power source or unplug the USB drive during bootloader update process, or else the data in the flash will be damaged causing a device malfunction and failure to boot up again.

This feature is implemented by the bootloader, it's crucial to flash with a working bootloader. A broken bootloader cannot be updated again. In this case you must re-program the Flash ROM through a hardware programmer.


The USB drive must be in FAT file system or the file cannot be recognized by the LinkIt Smart 7688 development platform.


  1. Save the bootloader file (lks7688.ldr) in the root directory of a USB drive and make sure the filename is kept as lks7688.ldr. You can download the latest bootloader from Downloads page.
  2. Plug in the USB drive to the LinkIt Smart 7688 development board.
  3. Press the WiFi and MPU (Reset) buttons at the same time, then release the MPU reset button while still holding the WiFi button for at least 20 seconds.
  4. After 20 seconds the WiFi LED will turn on. Release the WiFi button.

The board will read the bootloader (the WiFi LED blinks fast) and perform the bootloader update process (the WiFi LED blinks slowly). It takes about 2 seconds to finish the bootloader update process.