There's even a name for that type of kernel in the OSDev Wiki.
It's called Megalithic Kernel, and it should be a mode to run the OS for Windows, Linux or any other OS that we should be able to enable or disable at will (enable for high/low level development, and disable for regular user usage):http://wiki.osdev.org/Megalithic_Kernel
There is a reason why Paleolithic, oh, sorry, Mega
lithic kernels have been abandoned for all but the simplest embedded projects: they scale horribly, even (or especially, given real-time constraints when servicing multiple functions) for embedded systems. They are a relic of the past, and have no future to speak of, cannot have any future to speak of, because a system that lacks multitasking will never
make adequate use of the CPU and other resources.
I keep telling you that this is not a match for what you seem to be looking for, and that an Exokernel
would be closer to what you seem to want, but you seem to be fixated on MS-DOS as some kind of ideal.
Let me be as blunt as possible: FOR A CURRENT-GENERATION OS, RUNNING IN REAL MODE IS A FAILURE, NOT A FEATURE
. It does not
simplify the system, it makes it needlessly complicated because you spend your time getting around its limitations, usually by leaving
real mode at the first opportunity. I remember just what a pain in the butt working in MS-DOS was, and trust me, while few people went out of their way to switch to Win95 immediately, almost no one
regretted that they switched eventually (or more typically, never used MS-DOS in the first place, because in 1995-97 more computers pre-loaded with Windows 95 were sold to first-time owners than were sold for all computer types to all user types prior to 1995).
In any case, this is going to be irrelevant soon, as the next generation of Intel x86-64 processors is reportedly going to eliminate real mode and
32-bit protected mode entirely, and boot exclusively in long mode (with p-mode emulation similar to the old V86 mode). Some of the low-power embedded models (e.g., the Quark CPUs used in the Edison SBC) already have dropped real mode, and with the growing support for UEFI, it is likely that x86 will be 64-bit only by 2018 - assuming that the world hasn't finally come to its senses by then and dropped x86 as the junk it is, though I doubt that will happen even though everyone, including Intel, has been looking to do just that for nearly twenty years.