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tools/unbrick_k5_v1/README.md

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+# Unbricking the UV-K5 V1
+
+Restoring a UV-K5 V1 accidentally flashed with the F4HWN 4.3 Fusion 🔥 Edition firmware, using OpenOCD and a ST-LINK programmer.
+
+## Introduction
+
+Some users have accidentally flashed a UV-K5 V1 with the F4HWN 4.3 Fusion 🔥 Edition firmware. This edition **is only** compatible with:
+
+- UV-K5 V3
+- UV-K1
+
+When flashed onto a UV-K5 V1, it causes a complete brick, such as:
+
+- The radio does not power on anymore
+- DFU mode is unavailable
+- No LED activity
+- Flashing tools cannot detect the device
+
+Fortunately, the UV-K5 V1 can be fully restored by using OpenOCD and a ST-LINK programmer.
+
+## Requirements
+
+You will need:
+
+- A ST-LINK V2 programmer (original or clone)
+- Four Dupont jumper wires
+- A small screwdriver to open the radio
+- A computer with OpenOCD installed (Windows / macOS / Linux).
+
+## SWD connection points on the UV-K5 V1
+
+The radio must be opened to access the front side of the PCB.
+The UV-K5 V1 exposes a 4-pin SWD (Serial Wire Debug) interface:
+
+|Signal|  UV-K5 V1 Pad|    ST-LINK Pin|
+|:-------- |:--------:| --------:|
+|SWCLK   |SWCLK pad |   SWCLK
+|SWDIO   |SWDIO pad |  SWDIO
+|GND |GND pad | GND |
+|3.3V |   VCC pad | 3.3V |
+
+> [!WARNING]
+> Do not connect the battery while using the ST-LINK.
+The ST-LINK provides 3.3V to the board.
+
+## Installing OpenOCD
+
+### macOS (Homebrew)
+
+`brew install openocd`
+
+### Windows
+
+Download the official build from:
+
+- [Website](https://openocd.org/pages/getting-openocd.html)
+- [GitHub](https://github.com/openocd-org/openocd/releases)
+
+### Linux (Ubuntu / Debian)
+
+`sudo apt install openocd`
+
+### Verify installation
+
+`openocd --version`
+
+## Unbrick procedure
+
+### Connect the ST-LINK
+
+1. Connect the ST-LINK pins to the SWD pads:
+
+	* 3.3V → 3.3V
+	* SWDIO → SWDIO
+	* SWCLK → SWCLK
+	* GND → GND
+
+2. Plug the ST-LINK into your computer.
+3. Power on your UV-K5 V1 (normal mode).
+
+### Flash the bootloader
+
+From the unbrick_k5_v1 directory:
+
+#### Option A — Use the helper script
+
+`
+./unbrick_k5_v1.sh
+`
+
+#### Option B — Run the OpenOCD command manually
+
+`
+openocd \ 
+  -f ./interface/stlink.cfg 
+  -f ./target/dp32g030.cfg \
+  -c "init; reset halt; uv_flash_bl bootloader.bin; shutdown"
+`
+
+If no errors appear, the bootloader has been successfully restored. 
+
+- Disconnect and remove the ST-LINK from your UV-K5 V1 SWD port
+- Reinstall the battery
+- Power on the radio on DFU mode
+
+The device should now start correctly on DFU mode again. You can then flash stock firmware, or the [F4HWN firmware for UV-K5 V1](https://github.com/armel/uv-k5-firmware-custom) (not the Fusion Edition).
+
+# Disclaimer
+
+This procedure requires opening the device and directly manipulating its microcontroller over SWD. Incorrect use may permanently damage the radio. Proceed at your own risk.