Microkernels tend to do a lot of what you're talking about. They accomplish this via interrupts and virtual mapping of the device memory to userspace for the u

Microkernels tend to do a lot of what you're talking about. They accomplish this via interrupts and virtual mapping of the device memory to userspace for the userland app to access. "If we wanted, we could even replicate a kernel device driver style API in userland that network device drivers program against, done as a set of userland library files loaded dynamically based on detected hardware." This is how many microkernel based embedded RTOS's work. Common API's written for a hardware device, say a NOR flash chip, and the driver for the hardware onboard implements the interface specific to that hardware. You can then dynamically link the driver specific to your hardware. That's what I was doing as an embedded C developer some 10 years ago, and that solution had already been implemented for at least a decade (or 2) before that.