A lot depends on the platform. If the OS is for a WinTel motherboard it is one thing. If, however, the idea is to bypass driver development for a wide range of platforms it gets complicated.

In my experience one of the most painful aspects of bringing up an OS on a new platform is exactly this issue of drivers as well as file systems. A little google-ing quickly reveals that these are some of the areas where one might have to spend big bucks in the embedded world in order to license such modules as FFS (Flash File System) with wear leveling and other features as well as USB and networking stacks. Rolling your own as a solo developer or even a small team could very well fit into the definition of insanity. I have done a good chunk of a special purpose high-performance FFS. It was an all-absorbing project for months and, realistically, in the end, it did not match all of the capabilities of what could be had commercially.

This is where it is easy to justify moving into a more advanced platform in order to be able to leverage Embedded Linux. Here you get to benefit and leverage the work of tens of thousands of developers devoted to scratching very specific itches.

The down-side, of course, is that if what you need isn't implemented in the boad support package for the processor you happen to be working with, well, you are screwed. The idea that you can just write it yourself because it's Linux is only applicable if you or your team are well-versed in Linux dev at a low enough level. If that is not the case you are back to square one. If you have to go that route you have to hire an additional developer that knows this stuff inside out. That could mean $100K per year. So now your are, once again, back at square one: hiring a dev might actually be more exoensive than licensing a commercial OS with support, drivers, etc.

I was faced with exactly that conundrum a few years ago. We ended-up going with Windows CE (as ugly as that may sound). There are many reasons for that but the most compelling one may have been that we could identify an OEM board with the right I/O, features, form factor, price and full support for all of the drivers and subsystems we needed. In other words, we could focus on developing the actual product rather than having to dig deeper and deeper into low-level issues.

It'd be great if low level drivers could be universal and platform independent to the degree that they could be used as you suggest. Obviously VM-based platforms like Java can offer something like that so long as someone has done the low-level work for you. All that means is that you don't have to deal with the drivers.

To go a little further, part of the problem is that no standard interface exists to talk to chips. In other words, configuring and running a DVI transmitter, a serial port and a Bluetooth I/F are vastly different even when you might be doing some of the same things. Setting up data rates, clocks, etc. can be day and night from chip to chip.

I haven't really given it much thought. My knee-jerk reaction is that it would be very hard to crate a unified, discoverable, platform-independent mechanism to program chips. The closest one could possibly approach this idea would be if chip makers were expected to provide drivers written to a common interface. Well, not likely or practical.

Not an easy problem.