Debacular

When something turns out really bad, you say it was a debacle. If you're in the middle of something that you know is going to end badly, you say the whole process is debacular.

So, a post on comp.arch led to a Google search, which led to a website called OsDev. Now, I have a directory in my projects area called NedOs, which I have been trying to figure out what to do with. There's really not much stuff in there, but it seems a shame to delete it. So, why, not, you know, write an OS? It's not like I'm hugely busy in every dimension, right? (mmm, debacular already)

I broke out my Intel software developer manuals, but they are all so old, they don't have 64 bit stuff. I downloaded the new one, and was greeted by this:

Now, that is debacular!

For anyone who is thinking of writing their own OS, this is the flow chart for enabling "Long Mode" (that is - X86-64, AMD64, EMT64T, or as Intel has now started calling it IA32e mode!) (technically it handles all the modes)

After staring at it for a while (I just want 64 bit mode with paging, is that so wrong!), I realized this could be three sentences:

1. Enable PAE
2. Enable LME
3. Enable PG

You could have an optional fourth sentence - "The first two steps can be done in any order."

So, this picture is worth, like, -994 words.