My argument for a logical interface to devices would be to exactly allow the flexibility to implement one version of the platform with say, I2C and another fully parallel.

The required flexibility to implement a binary compatible platform across divergent implementations is simply accrues to the back-end driver which supports the front end API.

I am not arguing for a complex model like WIN-CE, instead a "tiny" model where devices have a logical definition of capability and it's up to the device itself to handle any divergence.

If i am going to ask mass storage for a file record of length "N" to load into buffer @ address "X", why should the executing task care that it arrives from serial or parallel transmitted data? I request the data and the request either completes or it doesn't.

Perhaps the best way to test the utility of the concept would to present the requirements for the API and to explore how they could implement simply if abstractly.

regards,
p