> For the complete documentation index, see [llms.txt](https://docs.sky-drones.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sky-drones.com/avionics/legacy-autopilots/flashing-bootloader.md).

# Flashing Bootloader

## Tools Required

Manufactured boards come WITHOUT bootloader pre-installed. You can easily flash them yourself. The tools needed include:

* ST-Link v2 ARM JTAG Debugger
* ARM JTAG Mini connector 1.25 mm pitch

## Connections

ST Link debugger looks something like this:

![](/files/-MTPndCremvt6l7Ym9ez)

You will need to connect the ST-Link pins to your SmartAP Pins.

The reference for ST Link pins:

![](/files/-MTPndClPJbg6ABNxanb)

The reference for SmartAP JTAG pins (view from top):

![](/files/-MTPndCk1N6s3OHpO4Xe)

Your connection should look like the below:

![](/files/-MTPndCmJs8nVu_YqoCS)

Your autopilot and ST Link debugger should be powered via USB only.

## Flashing

Open STM ST Link Utility and then go to `Target` > `Program and Verify`:

![](/files/-MTPndCqFIPzDUvraVHW)

Select the bootloader file to flash:

![](/files/-MTPndCo9s00eUjMgi14)

Finally, press `Start`

![](/files/-MTPndCpp0a2Im98-sPt)

Once completed you'll see the following:

![](/files/-MTPndCno7PbMxymX4Nd)

If you now see the board LEDs flashing, congratulations! Bootloader has been successfully flashed! Now you're able to install the firmware.