You might have heard the word “Bootloader” several times. Android devices with Qualcomm chipset have a PBL i.e. Primary Boot Loader. Understand it as the part of your chipset that boots up your device every time you turn ON your Android smartphone. However, few might know that there is an alternative boot mode as well which is called EDL mode. EDL (Emergency Download Mode) on Qualcomm chipsets allow the OEM to flash the software on the device in case of boot loop, or bricked devices. Keep in mind that this cannot be modified and has to take full control over the Android device’s storage.
Smartphone manufacturers like OnePlus, Xiaomi, etc have released a software tool which is called programmers that utilizes EDL and Firehouse protocol to unbrick the device. Firehouse can run a number of commands and also has the capability to examine the device’s data. And in this post, we will guide you on what is Qualcomm’s EDL mode and how do we access it. So, without any further ado, let us get straight into the article itself:
What is Qualcomm’s EDL mode? How do we access?
Before we head on to the details of the EDL mode, it is necessary to understand that according to security researchers Roee Hay (@roeehay) and Noam Hadad from Aleph Research came out with a theory that critical vulnerabilities using this mode that gives the hacker full access to your smartphone. However, this method requires physical access to the device but still, it is dangerous and cannot be patched. You can check out the list of devices that are affected by this exploit below:
- LG G4
- Nokia 6 (d1c)
- Nokia 5
- Nexus 6 (shamu)
- Nexus 6P (angler)
- Moto G4 Plus
- OnePlus 5 (cheeseburger)
- OnePlus 3T
- OnePlus 3
- OnePlus 2
- OnePlus X
- OnePlus One
- ZTE Axon 7
- ZUK Z1
- ZUK Z2
- Xiaomi Note 5A (ugglite)
- Xiaomi Note 5 Prime (ugg)
- Xiaomi Note 4 (mido)
- Xiaomi Note 3 (jason)
- Xiaomi Note 2 (scorpion)
- Xiaomi Mix (lithium)
- Xiaomi Mix 2 (chiron)
- Xiaomi Mi 6 (sagit)
- Xiaomi Mi 5s (capricorn)
- Xiaomi Mi 5s Plus (natrium)
- Xiaomi Mi 5x (tiffany)
- Xiaomi Mi 5 (gemini)
- Xiaomi Mi 3 (cancro)
- Xiaomi Mi A1 (tissot)
- Xiaomi Mi Max2 (oxygen)
- Xiaomi Redmi Note 3 (kenzo)
- Xiaomi Redmi 5A (riva)
- Xiaomi Redmi 4A (rosy)
Boot Sequence of Qualcomm Android Phone – Explained
SBL (Software Bootloader) is which is checked for authenticity before it is loaded to the memory chip imem. For naive, imem is a fast-on-chip that is used for debugging and DMA (direct memory access) and is exclusive to Qualcomm chipsets. Besides, in some device, XBL (extensive bootloader) is found in which the process of booting is the same. The SBL or XBL then launches the ABOOT (Android Bootloader) after which Fastboot is implemented. The SBL or XBL (in some occasions) check for the authenticity of signed or unsigned ABOOT.
