Thursday, August 12, 2010

It started with Hello

So there I had it, some very simply boot code that brought my emulator alive, if only enough to stutter the words 'NickOS v0.1 is loading' and then stall. It didn't die, but it didn't do anything more either. This all sounds very uneventful, and indeed you're right, it is. But it's exciting too, to appreciate just how alone this code is on the machine. There's nothing else running except for those few bytes of hand crafted assembly, no friendly API's, no drivers, no...well you get the idea....there's nothing. At least, not much.

So, once you get to this famed position, the question likely strikes (at least it did me); where to from here? So I looked ahead and tried to figure out what I wanted my OS to do...

...thought...

I emerged from my time of thinking with some ideas:
  • I wanted NickOS to run in protected mode, with access to the higher parts of memory and probably using paging too.
  • I wanted to load some kind of kernel separate from the boot loader. 
  • The kernel should manage memory, maybe allow multitasking, 
  • And I needed to read from a disk and draw to the screen. 
  • And, of course, I wanted to ultimately write programs that would run on NickOS
And all of a sudden, the chasm between what I had accomplished here, my lonely isolated piece of code, and what I was shooting for seemed incomprehensibly wide. I was immediately faced with more questions than I had answers and so began a few more days of simple thought.

...thought...

So rather than trying to write the entire kernel in one, I would work on each piece separately, one step, one baby step, at a time. And where better place to start, than protected mode.

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