If we ask this a different way, is there a single self executable file when written to the sector of the disk the hardware looks for can contain the instructions for the hardware and the weights all in one?
I can't thing of any informational theory reason why this can't be the case. The only thing I can think of structuring such far more complex and less worthwhile than just having separate layers. Dealing with this biological/intelligence mess in humans is already hard enough as it is.
The OS bootstraps the hardware and allows the software to run. If your software is contained in the same blob then great, but it still needs the bootstrapping code first.
The bootstrapping/hardware management portion on its own would be considered an OS but the LLM code would not, I think thats the main distinction here.