Anatomy of an Android smartphone: how the hardware and software inside works

A ​​modern smartphone based on Android is a complex system comparable in computing power to computers 10 years ago. But unlike a PC, where components can be easily replaced, in a smartphone everything is packed into a compact case, and the interaction between hardware and software is hidden from the user. Understanding the internal architecture will help not only to consciously choose a new device, but also to diagnose problems, optimize performance, or even modify the system to suit your needs.

In this article we will examine Android smartphone how the designer: from the chips on the motherboard to the layers of the operating system. You'll learn how the processor processes tasks, why the amount of RAM affects multitasking, where the firmware is stored, and how drivers connect hardware modules to applications. We will pay special attention to a unique feature of Android - the HAL (Hardware Abstraction Layer) abstraction, which allows one version of the OS to work on thousands of different devices..

The material will be useful for both novice users and those who plan to delve deeper into Android development or customization firmware We avoid unnecessary technical terminology, but where we cannot do without it, we give simple analogies. For example, let's compare Bootloader with a security guard at the entrance to a building, and Kernel with a dispatcher distributing resources between “tenants” (applications).

1. Hardware platform: the “brain” and “organs” of a smartphone

The basis of any smartphone is motherboard (motherboard), on which key chips are located. Their configuration determines the capabilities of the device: from data processing speed to support for certain functions (for example, 5G or wireless charging). Let's look at the main components:

• 🧠 Central processing unit (CPU) —the “brain” of the device. Modern smartphones use multi-core chips (for example, Qualcomm Snapdragon 8 Gen 3 or MediaTek Dimensity 9300), where the cores are divided into high-performance (for heavy tasks) and energy-efficient (for background).
• 🖥️ Graphics processing unit (GPU) - is responsible for rendering graphics. Popular solutions: Adreno (in Qualcomm chips) and Mali (in Exynos/MediaTek processors).
• 🧩 System on a chip (SoC) - combines the CPU, GPU, modem, image processor and other components in one chip. Examples: Apple A17 Pro (yes, this is iOS, but the architecture is similar), Google Tensor G3.
• 💾 Random access memory (RAM) — temporary storage for active applications. Volume from 6 to 24 GB (in 2026 flagships).
• 🗃️ Read-only memory (ROM/Storage) - the system, applications and user files are stored here. Types: UFS 4.0 (fast) or eMMC 5.1 (budget).

It is important to understand that performance depends not only on “bare” characteristics, but also on optimizing the interaction between components. For example, Samsung Exynos 2400 may lose Snapdragon 8 Gen 3 in benchmarks due to less efficient heat management, although on paper their parameters are similar.

⚠️ Attention: Some budget smartphones use cut down versions of SoC (for example, Snapdragon 6xx instead of 8xx), which limits support for functions like 8K video recording or working with neural networks. Before purchasing, check the full name of the chip in the specifications.

2. Android architecture: a layer cake of software

The Android software is built on a modular principle, where each layer is responsible for its own task. This allows you to update components independently of each other (for example, fix an error in WebView without flashing the entire system). Let's look at the structure from bottom to top:

Layer	Components	Functions
Linux Kernel	Linux kernel (versions 5.x–6.x)	Memory management, processes, drivers, security (SELinux).
HAL (Hardware Abstraction Layer)	Libraries .so, drivers	Communication between hardware and the upper layers of the OS. For example, camera HAL to work with the camera module.
Android Runtime (ART)	Virt. ART machine, libraries libart.so	Execution of application bytecode (files .dex).
Native Libraries	C/C++ libraries (libc, OpenGL)	Support for low-level operations (graphics, encryption).
Java API Framework	Managers (Activity, Window, Telephony)	Interfaces for application developers.
System Apps	Google Play, Settings, Phone	Pre-installed system applications.

The key feature of Android is open codificationManufacturers can modify any layer. (except for the Linux kernel, licensed under the GPL). For example, Samsung replaces the standard launcher with One UI, and Xiaomi integrates into the system proprietary services like MIUI Optimization.

Why Android fragmented?

Fragmentation occurs due to the fact that manufacturers adapt the OS to their hardware, add their own shells and delay updates. For example, Pixel 8 receives new versions of Android on the day of release, and Redmi Note 12 after 3-6 months. This leads to the fact that there are thousands of devices on the market at the same time with different versions of the OS. security patches.

3. Bootloader and startup process

When you press the power button, the smartphone goes through several initialization stages before the desktop appears on the screen. This process is controlled by bootloader a low-level app that checks the integrity of the system and transfers control to the kernel. is as follows:

1. ROM Boot — the primary bootloader in the memory chip, launches Bootloader.
2. Bootloader —checks the digital signature of the firmware (protection against unauthorized changes).
3. Kernel —initializes drivers and equipment.
4. Init Process — launches system services (zygote, servicemanager).
5. System UI — displays the user interface.

On most devices Bootloader is blocked by the manufacturer. This prevents the installation of custom firmware, but protects against malware. Unlocking (via fastboot oem unlock) resets the device and may void the warranty.

⚠️ Attention: Some manufacturers (for example, Huawei or Oppo) use proprietary protocols to lock the bootloader. Trying to unlock without an official key may lead to "briku" (complete inoperability) of the device.

4. Memory and storage: where and how data is stored

In Android, data is divided into three types according to the storage method:

• 📱 Random Access Memory (RAM) — temporary data of active applications. Cleared upon reboot.Modern smartphones use LPDDR5X (low-voltage memory with high bandwidth).
• 📁 Internal storage (ROM) - divided into:
  • /system — system files (read only).
  • /data — user data and applications.
  • /cache — temporary update files.
• 💾 External storage — microSD (if supported) or cloud services (Google Drive, OneDrive).

Operating speed depends on the type of memory:

- UFS 4.0 (in flagships) provides read/write speeds up to 4200/2800 MB/s.

- UFS 3.1 - up to 2100/1200 MB/s.

- eMMC 5.1 (budget models) - up to 250/125 MB/s.

Interesting fact: Android uses memory compression mechanism (zRAM)which allows you to "decompress" data on the fly. This increases the effective amount of RAM at the expense of the processor. For example, on Pixel 7 with 8 GB RAM is actually available up to 12 GB thanks to zRAM.

5. Drivers and HAL: a bridge between hardware and software

HAL (Hardware Abstraction Layer) is a set of interfaces that allow Android to interact with hardware components without being tied to a specific model. For example, the same code for turning on the camera will work on both Samsung Galaxy S24and Nothing Phone 2, because manufacturers implement a standard interface. ICameraProvider.

Drivers are divided into two types:

- Proprietary - closed drivers from the manufacturer (for example, for modems Qualcomm).

- Open -open source drivers (for example, for a touch screen).

Often problems with custom firmware arise precisely because of the lack of proprietary drivers.

Example HAL structures for the camera:
/vendor/lib64/hw/
├── android.hardware.camera.provider@2.6-impl.so // Implementation of HAL
├── camera.qti.so // Qualcomm driver
└── libarcore_hwbinder.so // ARCore support

⚠️ Attention: When installing custom firmware (for example, LineageOS), be sure to check the availability of the package vendor blob for your model, the camera, modem or sensors will not work.

6. Security: How Android Protects Data

Android uses a multi-level security system, where each component is responsible for its part:

• 🔒 SELinux — mandatory check of access rights for all processes (mode enforcing).
• 🛡️ Verified Boot — checking the integrity of system files at boot (via tree hashes dm-verity).
• 🔐 Keystore —hardware key storage (for example, for Google Pay or Biometric Auth).
• 📱 Sandboxing —each application runs in an isolated environment (UID).

Starting with Android 10, Google introduced Mainline Project — updating critical components (for example, Media Codecs or DNS Resolver) through Google Play, bypassing manufacturers. This reduced the time to fix vulnerabilities from months to days.

7. data-i="189">Android firmware consists of several sections, each of which can be updated independently:

Android firmware consists of several sections, each of which can be updated independently:

Section	Contents	Can it be changed?
boot	Kernel and ramdisk	Yes (requires unlocking the bootloader)
system	OS and pre-installed applications	Yes (via custom firmware)
vendor	Drivers and HAL	Partially (compatible ones required blob)
recovery	Recovery mode	Yes (for example, TWRP)
userdata	User data	Yes (but this is a factory reset)

Updates are of two types:

- OTA (Over-The-Air) — "by air", via Settings → System → Software update.

- Manual —via fastboot or recovery (for example, adb sideload update.zip).

Manufacturers often modify the update process. For example, Samsung uses Odine for firmware via PC, and Xiaomi — Mi Flash ToolBefore updating, always check the compatibility of the version with your model!

What is an A/B section?

Modern Android devices use an A/B scheme, where the system is installed in two partitions (system_a and system_b). When updating, data is written to an inactive partition, and after rebooting the device switches to it. failure.

8. Modifications and custom firmware

One of the advantages of Android is the possibility of deep customization. Advanced users can:

• 🔧 Install custom recovery (TWRP, OrangeFox) for backups and firmware.
• 📱 Flash alternative OS (LineageOS, GrapheneOS, CalyxOS).
• ⚡ Apply fashion (for example, Magisk for root access or for sound). data-i="233">Example command for unlocking the bootloader (works on most devices): ViPER4Android for sound).
• 🔄 Edit DNS or hosts to block ads.

Example command to unlock bootloader (works on most devices):

fastboot flashing unlock
fastboot reboot bootloader

However, modifications have risks:

- Loss of warranty.

- Disruption of banking applications (due to SafetyNet).

- Possible "brick" when error.

❓ FAQ: Frequently asked questions about the device. Android smartphones

1. Why do smartphones with the same processor perform differently?

Performance depends not only on the SoC, but also on optimization of the firmware, cooling system, memory type (UFS vs eMMC) and background processes. For example, MIUI on Xiaomi Often criticized for redundant services that consume resources.

2. Is it possible to increase the amount of RAM?

Physically - no, but you can use virtual memory (zRAM) or functions like RAM Expansion (in some firmware), which reserve part of the permanent memory for the cache.

3. What is “flashing a smartphone”?

This is an installation or update of software (OS, recovery, modems) at a low level. You can flash official firmware from the manufacturer or custom one (for example, LineageOS).

4. Why do some applications not work after rooting?

Many applications (especially banking) check the integrity of the system through Google SafetyNet or Play Integrity API. Root access or modified firmware can trigger the protection.

5. on my smartphone?

Go to Settings → About phone → Processor model or use applications like CPU-Z or AIDA64.