Which OS? I didn’t get many results for BSD binder. Then I figured maybe you were joking about the “serious” part, so I tried windows binder, iOS binder, didn’t see much…
Including drivers, as since Project Treble, starting with Android 8 all new drivers are required to be userspace, talking with the kernel via Android IPC (aka Binder).
Traditional Linux drivers are considered legacy in Android.
Well the userspace part of the driver. If they were only userspace they couldn't actually use the hardware. They have to have to be part of Linux or a kernel module to be able to talk to the hardware.
