How an Android Emulator Works


ARM v7a chipset

An ARM v7a chipset is a good choice for an Android emulator. This chipset supports the ARMv7 and ARMv7TE instruction sets so you can write code for either. Alternatively, you can use a 32-bit version of ARMv7 if you’re building for a tablet or mobile phone.

An Android emulator based on the ARMv7a chipset has a built-in ARM processor. It provides the basic functionality of the Android OS and does not include Google-specific APIs. However, it does support root access and helps test the most common Android apps. Another option is to use a system image with Google-specific APIs.

X86 system images

Google has released Android 11 x86 system images that allow for ARM compatibility. This emulator version uses application binary interfaces (ABIs) that translate ARM binary instructions into x86 instructions without impacting the entire system. As a result, Android apps written for ARM can now be executed without performance overhead.

The x86 system images are now available in the Canary channel and will have full ARM emulation. They are only meant for development and debugging purposes on x86 systems. They should not be used for commercial services or hosted services.

Mountable disk images

An Android emulator uses mountable disk images (AVDs) to simulate the data on the flash partition of the actual device. These images contain the Android system and kernel, user data, and a simulated SD card. Each emulator instance needs a specific set of disk image files to operate correctly. These images are stored in the AVD private storage area.

Mountable disk images are created before an emulator is loaded. The emulator can’t erase a blank SD card, so we need a disk image. We can use the tools utility to create and copy disk images in Linux and Mac systems. You can also use the ADB push command to copy files to the SD image when the emulator loads. If you want to use a file system, you can use the -c option to specify a path to the image.

Ramdisk images

The Android emulator uses Ramdisk images to emulate the RAM of an actual device. These image files can be written to or deleted. In addition to the RAMdisk, the emulator uses writeable disk images to simulate the SD card and user data. To create these images, the emulator looks for them in a private storage area of the emulator’s AVD.

The Android emulator includes a toolbox for launching shell commands. This toolbox has 51 orders. BusyBox offers an even more comprehensive set. Android smartphones also come with the Shell toolbox.

User-data partition

The user-data partition in Android emulators is used to store the user-specific data for a specific session. When an emulator launches, it looks for the user-data images it needs in the AVD directory, the current working directory, or a custom location. The emulator will mount them and make them available for reading if they are found.

The super partition is one of the possible locations for rootfs. Specify it once and then use it again if you want to perform an A/B seamless update. Make sure you back up important data before you proceed.

Support for external devices

The Android emulator can simulate the user interface of an actual Android device. It allows you to change your software applications and configure device settings. For example, you can enable geolocation, network latency, camera, and battery state. An emulator is also a good choice for unit testing since you can easily pick up where you left off.

The Android emulator can run multiple applications simultaneously. Unlike the real thing, emulators are slower, so it’s essential to enable software rendering if you want to enjoy the whole experience. Without it, the emulator will show a white screen instead of a real-life display. To fix this, you can sync your apps to the emulator.