How to extract Android firmware: a complete guide to dump

The modern ecosystem Android provides users with enormous freedom of action, but sometimes standard functions are not enough. Device owners are often faced with the need to save the original operating system before experimenting, restore deleted system partitions, or simply study the internal structure of their gadget. The process of creating a complete copy of the software, or so-called firmware dump, is a fundamental skill for any enthusiast.

You can extract the firmware in different ways, and the choice of method directly depends on the processor manufacturer, the state of the bootloader and the availability of rights. root. Some methods require connecting to a computer and using the command line, while others are available directly from the smartphone menu. Understanding exactly how data is stored on your device will help you avoid critical errors that can turn your phone into a “brick.”

In this article we will look in detail at all the current methods for extracting system files, from simple scripts to low-level utilities for chips MediaTek i Qualcomm. We will pay special attention to data security and the correct procedure so that you can confidently work with the system partitions of your device.

Preparation of the workplace and necessary tools

Before you begin to extract system files, you must carefully prepare the software environment. The basic requirement for most methods is the presence of ADB i Fastbootdrivers installed on the computer. These components are included Android SDK Platform Tools and provide communication between the PC and the smartphone operating system.

The quality of the USB cable plays a critical role in the process of transferring large amounts of data. Cheap cables that only support charging can cause the connection to break at the most inopportune moment, which can damage the file system. Use an original cable or a certified analogue that supports high-speed data transfer.

You will also need enough free space on your computer's hard drive. A complete dump of a modern smartphone with a 128 or 256 GB drive can take up a significant amount of space, even if only system partitions are taken into account. It is recommended to create a separate folder in advance for saving images so as not to get confused in the files.

⚠️ Attention: Before starting any manipulations with system partitions, be sure to back up your personal data (photos, contacts, documents) to an external drive or to cloud storage. The process of dumping the firmware is safe for user data, but the human factor has not been canceled.

The method of creating a dump via ADB and the command line

The most universal way to extract the firmware works on most devices with an unlocked bootloader or acquired superuser rights. This method involves using the command dd through the shell ADB. It allows you to copy the contents of a specific section (for example, boot, recovery or system) to an image file on your computer.

To get started, connect your smartphone to the PC and make sure that the developer menu is activated in the menu Settings → About phone → Build number (press 7 times). Inside it you need to enable the “USB Debugging” item. After connecting, in the command line, enter adb devices and confirm the key fingerprint on the phone screen.

adb shell su -c"dd if=/dev/block/bootdevice/by-name/boot of=/sdcard/boot.img"
adb pull /sdcard/boot.img

The above code demonstrates the basic principle: first we copy the partition boot to the internal memory of the phone, and then with the command pull we transfer it to the computer. However, the path to block devices may differ depending on the processor architecture and version Android. On some devices, the path may look like /dev/block/mmcblk0p....

How to find the exact partition paths?

To determine the exact partition paths, use the command `adb shell ls -l /dev/block/bootdevice/by-name/`. It will display a list of all names and their corresponding block devices, which will allow you to generate the correct command for copying.

If the device does not have rights root, this method will not work for system partitions, since the command dd requires superuser privileges. In this case, you can try to extract only user data or use methods that do not require root access, but are limited in functionality.

Using SP Flash Tool for MediaTek devices

Owners of smartphones based on processors MediaTek have a unique advantage - the ability to work with memory at a low level even without an unlocked bootloader. The utility SP Flash Tool is a de facto standard for such operations and allows you to create complete backups of memory partitions.

To work, you will need a scatter file that describes the memory card of your specific device. This file can usually be found on developer forums (for example, 4PDA or XDA) for your model, or extracted from the official firmware. Without a correct scatter file, the app will not be able to determine the partition structure.

The process is as follows: select the “Readback” tab in the app menu, add a new region, specify the file name and size. The partition size is critical: if you specify less than the actual volume, the dump will be incomplete; if more, the process will be interrupted or the data will be damaged.

Parameter	Description	Where to find
Scatter File	Memory partition map	Forums, official ROM
Readback Start Address	Section starting address	Scatter file (Hex)
Readback Length	Section length for dump	Scatter file (Hex)
USB Port	Port connections	Windows Device Manager

📊 What processor is in your device?

MediaTek

Qualcomm Snapdragon

Samsung Exynos

Kirin / Other

⚠️ Attention: When working with the SP Flash Tool, it is extremely important not to confuse the operating modes. The “Format All + Download” mode will completely destroy the data on the phone, while the “Readback” only reads it. Be careful when choosing tabs.

Working with Qualcomm: QFIL and EDL mode

Devices on chips Qualcomm require a slightly different approach. Here the main utility is QFIL (Qualcomm Flash Image Loader) or a newer one QPST. To enter the firmware mode, a special mode is often used EDL (Emergency Download Mode), which allows you to interact with the bootloader directly.

To extract the firmware, you need to use the “Partition Manager” functionality inside the utility. This tool allows you to see a list of all partitions present on the device and save their contents to files. However, unlike MediaTek, it often requires a digital signature or an authorized account to access certain sections.

Entering EDL mode can be done programmatically via a command adb reboot edl (root required) or hardware - by closing certain contacts on the board (test points) when connecting the cable. For each phone model, the short circuit points are unique and require a search for circuits.

The reading process through QFIL can take a long time, especially if you decide to dump the entire drive. Speed ​​is limited by USB 2.0 throughput in download mode, so please be patient. Interrupting the process in this mode is also dangerous, although less critical than writing.

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Use a USB hub without its own power or an old USB 2.0 port to enter EDL mode if automatic detection does not work. Sometimes this helps to avoid driver conflicts.

Creating a backup via Custom Recovery (TWRP)

The most convenient and safe way for the end user is to use a custom recovery, such as TWRP (Team Win Recovery Project). This method does not require connecting to a computer while creating a copy and has a clear graphical interface.

After installing TWRP, you need to go to the “Backup” section. Here you will be asked to select partitions to save. The standard set includes Boot, System, Data and Vendor. The section Data contains all your applications and settings, so its size can be large.

• 📂 Selection of storage: It is best to save a backup on an external SD card or OTG flash drive so as not to occupy the internal memory of the device.
• 🔒 Encryption: TWRP allows you to install password for the backup, which will protect your data in case of loss of the memory card.
• ⚙️ Compression: The data compression option will reduce the final file size, but will increase the time it takes to create a copy.

The main advantage of this method is the ability to restore the system in a couple of clicks directly from the recovery menu. This is an ideal option for creating a “rollback point” before installing modifications, custom kernels or new versions Android.

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TWRP is the only method that allows you to make a full backup of encrypted user data (Data section) without losing access to it after recovery.

Partition structure analysis and file system

Understanding what exactly you are copying helps avoid confusion. The modern file system Android is divided into many logical parts. The section boot contains the Linux kernel and the initial ramdisk necessary to run the OS. The partition recovery stores the recovery environment.

The partition system (or system_a/system_b on devices with A/B partitioning) contains the operating system itself, pre-installed applications and frameworks. This is what they most often try to modify or save before flashing. The section vendor contains proprietary drivers and libraries specific to the hardware manufacturer.

Starting from Android 10, the dynamic partition mechanism and project Project Trebleare being actively implemented, which complicates the structure. Now system files can be packaged into an image super, inside of which there are logical volumes. To work with them, more complex tools are required, such as lpunpack.

What is A/B partitioning and how does it affect the dump?

A/B technology (or Seamless Updates) implies the presence of two sets of system partitions (slot A and slot B). While you are using one version, the second one is updated in the background. When creating a dump, it is important to understand which slot is active, or copy both, to have a complete picture. This doubles the amount of space taken up, but guarantees the safety of the update.

Is it possible to remove the firmware without unlocking the bootloader?

In most cases, no, if we are talking about full system images via ADB. However, methods through the SP Flash Tool (MediaTek) or EDL mode (Qualcomm) often bypass the bootloader lock, since they work at the level of chip boot protocols, not the operating system. But to access user data (Data), unlocking will still be required.

What is the difference between a firmware dump and a simple data backup?

A data backup saves only your personal information: photos, contacts, correspondence. A firmware dump is an exact copy of the contents of a memory chip, including the operating system, boot loaders, drivers, and partitions. A dump allows you to restore the phone to its factory-like state even after a complete software failure, while a data backup is useless without a working system.

Frequently asked questions (FAQ)

Is it safe to pull out the firmware on a phone with a warranty?

The reading process itself (dump) data usually leaves no trace and does not break software seals unless you unlock the bootloader. However, physically opening the case to access the contacts (test points) may damage the warranty stickers. Software methods via ADB are safe for warranty status if you do not modify the partitions.

How long does it take to create a full copy of the firmware?

The time depends on the amount of memory and the speed of the interface. Dumping the System partition (about 4-6 GB) via USB 3.0 will take 2-5 minutes. A complete copy of the entire 128GB drive can take anywhere from 20 minutes to an hour. Using USB 2.0 will increase this time by 3-4 times.

Is it possible to restore the firmware to another phone model?

Absolutely not. The firmware contains drivers and settings tailored for specific hardware (screen, camera, modem). Installing an image from another model is guaranteed to result in the device not working. Even different modifications of the same model (for example, with different amounts of memory) may be incompatible.

Where is the IMEI stored and how to save it when flashing the firmware?

IMEI and other unique identifiers are stored in a protected section NVRAM or EFS. When using standard dump methods (ADB, TWRP), these partitions are often hidden or require special read permissions. When flashing using official tools, they are usually saved, but with low-level formatting they can be lost, which will lead to loss of the network.