Where are the drivers in Android: architecture and access

Users moving from the classic Windows architecture to mobile platforms are often faced with a misunderstanding of how the low-level part of the operating system works. In the usual PC environment, drivers are separate files with the extension .sys or .inf, which can be found in the folder System32 and, if necessary, replaced manually. In the world Android the situation is radically different: here the concepts of "folders with drivers" are in the user's understanding, and hardware management is implemented through the monolithic Linux kernel and specific abstraction mechanisms.

The fundamental difference is that device drivers in Android they are most often built directly into the kernel image (kernel) or located in protected system partitions, access to which is prohibited without obtaining superuser rights. This is done for the safety and stability of the device, so that accidental removal or modification of a critical component does not turn the smartphone into a “brick.” However, for developers and advanced enthusiasts, there are legal ways to interact with this layer.

Understanding the physical location of these components is necessary not only for deep customization, but also for correct debugging of devices via a computer. When you connect your phone to a PC, it is the lack of the correct USB drivers on the computer side that becomes the most common reason for connection failure, although the device itself already contains everything necessary to work within itself. Let's take a look at where this data technically resides and how the system controls the hardware.

Driver architecture in the Linux and Android kernel

Any version of Android is based on the operating system kernel Linux. In this architecture, drivers are not independent executable files that are loaded on demand, as in Windows. Instead, the vast majority of codecs, display controllers, Wi-Fi and Bluetooth modules are compiled directly into a binary kernel image. This means that they are physically located inside a file boot.img or kernel, which is loaded by the bootloader (bootloader) when the device is turned on.

This approach ensures high performance and minimizes delays when accessing the hardware. However, it creates difficulties when updating: to replace a video accelerator driver, you often need to reflash the entire kernel, and not just one small file. This is the "monolithic" model that has dominated the mobile industry for many years. For the user, this looks like a “black box”: you can’t just go into Explorer and see the driver file.

The situation began to change with the introduction of the initiative Project Trebleintroduced in Android 8.0. This architecture separated the Android framework implementation from the low-level vendor implementation. Now drivers can be placed in separate sections, which allows you to update the OS without the participation of chipset manufacturers. However, the physical location remains hidden in partitions mounted only by the system.

⚠️ Warning: Direct modification of the kernel image or system partitions with drivers without in-depth knowledge may result in loss of warranty and device inoperability (bootloop).

System partitions and location of HAL files

If the kernel is responsible for direct hardware management, then the level HAL (Hardware Abstraction Layer) serves as a bridge between the kernel and high-level Android services. Files that implement HAL logic can be found on the file system, but access to them is limited. In modern versions of Android, these libraries are usually located in /system/lib and /system/lib64directories, as well as in vendor sections. /vendor/lib.

HAL libraries have the extension .so (Shared Object) and are named according to the principle hardware..default.so. For example, a camera driver can be represented by a file hardware.camera.exynos5.so. It is these files that tell the system exactly how to communicate with a specific module installed on the board of your smartphone. You can find them only through a terminal with root access or by connecting a file manager with superuser rights.

The directory structure may differ depending on the manufacturer. Chip-based devices often use proprietary blocks in a partition that is mounted as a separate entity. While devices on Qualcomm Snapdragon often use proprietary blocks in the section /firmware, which is mounted as a separate entity. While the devices are on MediaTek can store part of the data in the /persistsection, which retains the data even after resetting the settings. This is done to store calibration data and unique hardware identifiers.

• 📂 /system/lib/hw —the main implementations of hardware abstraction for standard functions are stored here.
• 📂 /vendor/lib/hw —specific libraries from the device manufacturer, often closed for viewing.
• 📂 /firmware/image —microcode for modems, DSPs and other specialized processors.

It is important to understand that simply copying these files from one phone to another will not make the hardware work. Drivers are strictly tied to a specific chipset and memory addresses. An attempt to replace the camera library from Samsung on the device Xiaomi will lead to an immediate system crash or reboot.

Drivers for connecting to a computer (ADB and Fastboot)

When it comes to “Android drivers” in the context of the average user, in 90% of cases it is not the internal structure of the system that is meant, but the software for computer. In order for your Windows PC to correctly recognize a smartphone in debug (ADB) or firmware (Fastbootmodes), the appropriate drivers must be installed on the computer.

Unlike internal system files, these drivers are standard components of the Google development ecosystem. They allow the computer's operating system to create a virtual COM port or network interface to communicate with the phone. Without them, Device Manager will show an unknown device with a yellow exclamation mark, and no commands will be executed.

Installation is performed either automatically through the installer Android SDK Platform-Toolsor manually by updating the driver in Device Manager specifying the path to .inf the file. In Windows 10 and 11, the system often tries to find a universal MTP driver for file transfer, but this is not enough for debugging. A specialized ADB interface driver is required.

adb devices
List of devices attached
0123456789ABCDEF device

If after connecting you see status unauthorized instead of device, the problem is not in the drivers, but in the security settings on the phone itself. You need to confirm your RSA key fingerprint in a pop-up window on your smartphone screen. This is a mechanism to protect against unauthorized access to data via a USB port.

⚠️ Attention: Never download ADB drivers from dubious aggregator sites. Use only the official Google USB Driver or Android Studio components to avoid the introduction of malware.

Project Treble and Generic System Image (GSI)

A revolutionary change in the issue of driver localization was the introduction of Project Treble. Before its introduction, vendor drivers were inextricably linked with the Android code, which made it difficult to release updates. Now the system is divided into two parts: the system partition (which can be universal) and the vendor partition (where the drivers live).

Thanks to this, the technology appeared GSI (Generic System Image). This is a system image that can run on any device that supports Treble, regardless of who manufactured the phone. Drivers are loaded from the section /vendor during boot. This means that the "place" of drivers is now standardized and separated from user data and the OS itself.

For developers, this has opened up the opportunity to test new versions of Android on a wide range of devices without waiting for custom firmware from enthusiasts. If the vendor has correctly implemented the HAL interface, then the GSI image successfully uses local drivers to control the screen, sound and communications. However, if the driver implementation in /vendor contains errors, GSI may be unstable.

Component	Location (path)	Access	Destination
Kernel	boot.img / kernel	Read only	Low-level hardware management
HAL libraries	/system/lib/hw	Root / System	Abstraction for Android framework
Vendor drivers	/vendor/lib/hw	Read only	Specific implementations from the manufacturer
Microcode (Firmware)	/firmware/image	System	Firmware for modem, WiFi, Bluetooth

How to access system driver files

For the average user, access to driver files is intentionally denied. The Linux permissions mechanism (SELinux) prevents even most applications from reading and writing to system partitions. To see these files, you will need to unlock the bootloader and gain root access (superuser rights). This gives complete control over the file system.

After gaining root access, you can use file managers like Root Explorer or MT Managerto navigate to the directory /system. However, be careful: modern versions of Android use the file system EROFS or mount partitions in read-only mode (ro). To make changes, you often need to remount the partition into write mode with the command mount -o rw,remount /system.

An alternative and safer way to study the structure is to use a terminal emulator and command ls. You can delete the contents of folders without the risk of accidentally deleting a critical file through the GUI. To analyze libraries, tools like readelf or objdumpare also used, which show driver dependencies.

• 🔓 Unlocking the bootloader is the first mandatory step, erasing all data from the device.
• 🛠 Installing Magisk is the most popular way to get root access without modifying the system partition directly.
• 💻 Using ADB Shell - allows you to view files through the computer with the command adb shell ls -l /vendor/lib.

It is worth noting that on devices with boot verification enabled (Verified Boot), any change in the driver sections will result in the phone refusing to boot. The system checks the digital signatures of all critical sections at startup. The only way to get around this is to disable verification, which further reduces the security of the device.

⚠️ Warning: Changing access rights (chmod) to system drivers can break SELinux and cause applications to stop seeing the hardware (for example, a camera or fingerprint sensor).

What is SELinux and why does it block access?

SELinux (Security-Enhanced Linux) is a kernel module that implements a mandatory access control policy. On Android, it works in Enforcing mode, severely limiting the capabilities of processes. Even with root access, some operations may be prohibited if they are not specified in security policies (sepolicy).

Compatibility issues and universal drivers

One ​​of the main headaches when working with Android devices on a PC is driver fragmentation. Each manufacturer (Samsung, Sony, LG, Huawei) uses its own VID (Vendor ID) and PID (Product ID) for USB controllers. Google's universal driver cannot always automatically pick up a specific device, especially in Download Mode or EDL (Emergency Download Mode).

EDL mode, which is used for deep recovery of "bricked" devices on Qualcomm processors, the phone is detected as Qualcomm HS-USB QDLoader 9008. To work with it, specific drivers are required, which are often not digitally signed by Microsoft. In Windows 10 and 11, installing such drivers requires temporarily disabling driver digital signature verification, which is a procedure with increased security risks.

There is also a problem with MTP (Media Transfer Protocol) drivers. If the computer sees the phone, but does not show the files, the problem often lies in a protocol version conflict or a damaged driver cache in the Windows system. In such cases, it helps to completely remove the device from Device Manager with the "Remove driver apps" checkbox and reinstall it.

For developers creating their own devices based on Android (Single Board Computers), it is important to comply with Device Tree standards. Errors in the description of the device tree lead to the fact that the kernel simply does not see the connected equipment, even if the driver is physically present in the assembly. Debugging such problems requires analyzing the kernel logs (dmesg), where you can clearly see which driver could not be initialized.

Frequently asked questions (FAQ)

Is it possible to update drivers on Android as on Windows?

No, in the classical sense it is impossible. Drivers are part of the firmware or kernel. The update occurs only when installing system updates (OTA) or flashing the entire device. There is no separate “video card driver” file for downloading.

Where can I download drivers for a specific phone to my computer?

The best source is the official website of your smartphone manufacturer in the support section. You can also use the universal Google USB Drivers from the Android SDK. Avoid third-party apps like "DriverPack", as they often install garbage.

Why does the computer not see the phone in ADB mode?

There may be several reasons: the ADB driver is not installed on the PC, only charging is enabled in the USB settings, the cable is faulty, or the debug key is not confirmed on the phone screen. Check the command adb devices for diagnostics.

Is it safe to delete files from the /system/lib/hw folder?

Absolutely not. Removing HAL libraries will lead to the inoperability of the corresponding equipment (camera, sound, sensors) and, most likely, to a cyclic reboot of the device. It will be possible to restore the system only through flashing.

What to do if the Qualcomm 9008 driver does not install?

Try to disable driver digital signature verification in Windows. Make sure you are using the original USB 2.0 cable and port (sometimes 3.0 causes problems with this mode). You may also need to install drivers in administrator mode via the command line.