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Before flashing a kernel or verifying a boot, you need two physical connections to your Qualcomm® Linux development kit: a USB connection for fastboot and ADB, and a serial console connection for early-boot log capture.

Required hardware

Set up the serial console

The Qualcomm® Linux development kits expose a debug UART over a USB-to-serial adapter. The serial console is the primary channel for inspecting early-boot messages, kernel panics, and U-Boot/UEFI output before the network stack is available.

Install a terminal emulator

Connect the USB-to-serial adapter

Plug the adapter into the host and identify the device node:
Add your user to the dialout group if permission is denied:

Open the serial console

Qualcomm Linux development kits use 115200 baud, 8N1, no hardware flow control:
To exit minicom, press Ctrl-A then X. To disable hardware flow control, open minicom settings with Ctrl-A O → Serial port setup and set Hardware Flow Control to No.
Alternatively, use picocom:
For board-specific UART pin assignments and adapter wiring, refer to the hardware documentation for your development kit.

Set up fastboot and ADB

Fastboot is used to flash kernel images; ADB provides shell access after the device has booted.

Install platform tools

Enter fastboot mode

After powering on the device, select Volume Down. The serial console shows:
The exact button combination varies by board. Refer to your development kit’s hardware documentation if the above does not work.

Verify fastboot connectivity

Expected output (the serial number varies by board):
If no device appears, check the USB cable, confirm the device is in fastboot mode, and verify USB permissions:

Verify ADB connectivity (post-boot)

After the device has fully booted, ADB should enumerate over the same USB cable:
Expected output:
Open a shell:

Next steps

With serial console and fastboot confirmed, proceed to Install & boot the kernel to flash your build and verify the running kernel.