How to unbrick KVM via USB OTG¶

This tutorial explains how to unbrick a GL.iNet KVM device using USB OTG. This method is suitable for situations where the KVM device is bricked and cannot be restored via a standard firmware update or U-Boot safe mode.

Supported devices¶

RMQ1

Prerequisites¶

Please prepare the following tools to unbrick the device.

A Windows running Windows, macOS or Ubuntu

Note

Do not connect the RMQ1 to a power adapter via its USB-C port.
Before flashing the firmware, back up the factory partition to preserve device-specific data (such as the MAC address and certificate). If the Web UI remains accessible, please navigate to Toolbox → Terminal → Access, and run the following command:
```
dd if=/dev/mtd6 of=/userdata/media/factory.bin
```
The backup file will appear in Virtual Media and can be downloaded to your local computer.
Do not disconnect the USB-C cable between the RMQ1 and the computer during the recovery process; otherwise, the device may be damaged.
If you want the device to reboot automatically after the flashing, navigate to Settings → Options → Reboot to Normal Mode After Download and enable it before you begin. If this option is not enabled, you must manually reboot the device after the flashing is complete (i.e., by unplugging and reconnecting the power cable).

Unbirck Steps¶

Windows¶

Download the U-Boot firmware for your RMQ1 device to your computer from here (select DOWNLOAD FOR USB OTG).
Install the USB drivers:
- Download the driver package to your computer from here and extract it to any directory.
- Double click the DriverSetup.exe file to run the installer.
Install the AXDL Tool.
- Download AXDL to your computer from here and extract it to an easily accessible directory.
- Double click the AXDL.exe file to run the flashing tool.
Open the AXDL panel, click load.axp, and select the firmware downloaded in Step 1 to upload it.

Click Start downloading.
Power off your KVM device. Press and hold the RESET button on the bottom of the RMQ1, connect the device to your computer using the included USB-C cable.
Upon seeing Downloading... in the status column, release the RESET button.
Wait until the AXDL tool displays Passed to confirm that the flashing process is complete.

macOS / Linux¶

The official AXDL tool is Windows-only. For macOS and Linux, you can use axdl-rs—an open-source, unofficial Axera image downloader written in Rust.

Install the Rust toolchain via rustup
Download the U-Boot firmware for your RMQ1 device to your computer from here (select DOWNLOAD FOR USB OTG).

Install platform-specific dependencies:

Linux (Debian-based)

sudo apt install -y libudev-dev libusb-1.0-0-dev

Configure udev rules to allow regular users to access the device:

# Clone the repository
git clone https://github.com/gl-inet/axdl-rs.git

# Change directory
cd axdl-rs

# Copy the udev rule file to the system directory
sudo cp 99-axdl.rules /etc/udev/rules.d/

# Reload udev rules to apply changes
sudo udevadm control --reload

If the user is not in the plugdev group, please add them to the group, then re-log in for the changes to take effect.

sudo usermod -a -G plugdev $USER

macOS

Install libusb via brew to enable USB communication with KVM devices:
```
brew install libusb
```
Build the axdl-cli tool
```
cargo build --bin axdl-cli --package axdl-cli
```

Enter the following command to flash the firmware. Please replace the /path/to/firmware.axp with the actual path to your downloaded firmware file.
```
cargo run --bin axdl-cli --package axdl-cli -- --file /path/to/firmware.axp --wait-for-device
```
The tool will display Waiting for device to be ready and enter a waiting state.
Power off your KVM device. Press and hold the RESET button on the bottom of the RMQ1, connect the device to your computer using the included USB-C cable.

Wait until the flashing process is complete.

Note: Once flashing is complete, the device may not reboot automatically. Manually power cycle (power off and on) the RMQ1 to activate the new firmware.

Expected Output

After a successful flash, the terminal will display the output below.

Note: compiler warnings can be safely ignored"

$ cargo run --bin axdl-cli --package axdl-cli -- --file glkvm-RMQ1-nand-1.8.1-0518-1779101289.axp --wait-for-device
warning: `axdl` (lib) generated 6 warnings
   Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.07s
   Running `target/debug/axdl-cli --file glkvm-RMQ1-nand-1.8.1-0518-1779101289.axp --wait-for-device`
Waiting for the device to be ready
Loading the AXP image configuration
Start download
Handshaking with the device
Downloading the flash downloaders
[00:00:03] [############################################################################]
Downloading the partition table
Skipping partition: FACTORY (excluded by default)
Downloading image DDRINIT
Downloading image UBOOT
Downloading image LOGO
Downloading image DTB
Downloading image KERNEL
Downloading image RECOVERY
Downloading image MEDIA
Downloading image ROOTFS
[00:00:26] [############################################################################]
Downloading image SPL
Done