Android: how Linux interacts with host devices?

Question

How the Linux drivers interact with the host devices through the Android Emulator? I mean for instance how a virtual sound device driver, compiled for ARM and running inside of the Emulator communicates with the actual speaker on the computer.

I heard that you need to use a special kernel image when running on top of the Emulator, so I imagine that the drivers do some magic but I couldn't find any information on the web nor locate the drivers on the git repositories.

Answer 1

It uses the goldfish virtual platform that's in Android kernel: it's a special platform ARM architecture, made to interact with the custom Qemu that Android uses:

Qemu code:
https://android.googlesource.com/platform/external/qemu/+/froyo-release/android

Android kernel code:
https://android.googlesource.com/kernel/common/+/deprecated/android-2.6.39/arch/arm/