XBB From Start to Finish
From XOmB wiki
XBB From Start to Finish
This is a series that goes from boot to kmain and beyond! A practical guide to the beginnings of kernel development.
So you'd like to know all about how XBB works, would you? Well, you've come to the right place. Here's a quick rundown of what's in each article, or, you can just click on the menu on the right to go to any of them.
Contents |
[edit] Start to Finish: Grub
The first part of the process involves Grub. Grub handles actually booting the machine, doing a bunch of housekeeping, and then transitioning to our code.
[edit] Start to Finish: Switching to Long Mode
Since XBB is 64 bit, we need to actually transition to long mode, also known as 64 bit mode. This whole process takes place in assembly, and, honestly, it kinda sucks.
[edit] Start to Finish: Moving From Low to High Memory
The next step is to transition from low to high memory. Programs expect to run in low addresses, so we need to make room for them. Our job is to make things nice for processes, not for it to be simple.
[edit] Start to Finish: Calling kmain
Now that all of the housekeeping is done, we're ready to transition into the kernel itself. kmain is where it all goes down.
[edit] Start to Finish: Printing to the Screen
Finally, we include a kprintfln implementation as an example of some of D's features, and because printing to the screen is useful. Also, it's a good indicator that everything's up and running and working correctly. A blank black screen just isn't as awesome.