Emergency Download Mode (EDL) is a hardware-level Qualcomm feature that lets a PC communicate directly with the Snapdragon chipset, bypassing the Android OS entirely. Windows sees it as a Qualcomm HS-USB QDLoader 9008 COM port. Without the correct driver, Device Manager shows an unknown device and no flashing tool can connect. This guide covers driver installation, how to enter EDL, and which tools use it.
Every Qualcomm Snapdragon SoC contains a small read-only bootloader called PBL (Primary Boot Loader) burned into the chip at manufacture. When the PBL cannot find a valid secondary bootloader — either because flash is blank, corrupted, or because specific hardware test points are shorted — it falls through to EDL mode automatically.
In EDL, the phone presents a Qualcomm Serial interface over USB. The PC communicates with it using the Sahara protocol (for handshake) and then the Firehose protocol (for partition read/write). Because this is implemented in ROM, it cannot be disabled by software and it works even on completely bricked devices that will not boot at all.
The USB Product ID in EDL mode is always 0x9008 under Qualcomm's Vendor ID 0x05C6, which is why the driver and the mode are commonly called “9008.”
The driver you need is Qualcomm HS-USB QDLoader 9008. It is not distributed standalone by Qualcomm but is bundled with several tools:
After installing any of these tools, the driver is registered in Windows. You do not need to run the tool itself to use the driver for other purposes.
The Qualcomm EDL driver shipped with some tools is not signed with a modern Microsoft signature, or is signed with a certificate that has expired. Windows 10 and 11 with Secure Boot enabled will refuse to load unsigned or improperly signed kernel drivers.
The correct fix is to use a driver package that is properly signed. The driver bundled with MiFlash 2020 or newer, and with recent QFIL packages, carries a valid signature. If you have an older bundle:
Do not enable Test Signing mode or disable Driver Signature Enforcement on production machines — this weakens the security of the entire system. Use a properly signed driver package instead.
There are three ways to enter EDL, listed from safest to most invasive:
Via ADB command (if Android is still booting):
adb reboot edlThis works on Xiaomi, OPPO, and Realme devices with ADB enabled. The phone immediately enters EDL and appears as the 9008 COM port.
Via Fastboot command (if Fastboot is accessible):
fastboot oem edlSupported on some Qualcomm devices. Not universal.
Via hardware test points (for completely bricked devices): Specific solder pads on the motherboard, when shorted together while connecting USB power, force the Snapdragon PBL into EDL. The exact pads vary by board revision and model. This requires disassembly and is a last resort for unbootable devices.
With the device in EDL and the driver installed, open Device Manager and expand Ports (COM & LPT). You should see Qualcomm HS-USB QDLoader 9008 (COM X) where X is an assigned port number. Note the COM number — QFIL and other tools will ask for it.
If the device appears under Other devices as QHSUSB_BULK or similar, the driver is not loaded. Right-click and update the driver as described above.
QFIL (Qualcomm Flash Image Loader): Official tool for flashing rawprogram XML + image files. Used by manufacturer service centers. Requires a valid Firehose programmer file (.elf or .mbn) for the specific device.
MiFlash: Xiaomi-specific wrapper around QFIL. Uses pre-packaged fastboot ROM files or EDL ROM files from Xiaomi's download server.
EDL.py / bkerler's edl tool: Open-source Python implementation of the Firehose protocol. Supports most Snapdragon devices without needing QFIL. Can dump partitions, flash images, and read GPT tables.
Chimera / EFT / UFI: Commercial service-box tools used by repair shops. Support EDL on a wider range of devices including models that require proprietary authorization (auth files signed by the manufacturer).
On older Qualcomm devices (pre-2019), EDL was fully open: any Firehose programmer could connect without authentication. On newer devices, manufacturers have implemented EDL auth: the device will only accept a Firehose programmer signed with the manufacturer's private key. Xiaomi, OPPO, Vivo, and others began enforcing this from roughly 2019–2020 onward. Without the correct signed programmer, QFIL connects to the COM port but the Firehose handshake fails. The workaround — obtaining leaked or extracted programmers — exists in the community but is outside the scope of this guide.