16-bit to 32-bit Operating System

How to run

• Type make in this directory. This will compile the operating system into an os-image.bin, which can be used by the Bochs emulator to emulate the operating system.
• After compiling, run Bochs in this directory by either
• • Pressing Run (if on Replit)
  • typing bochs -f bochsrc.txt -q in the shell in this directory
  • typing make run in the shell in this directory, which will automatically compile the OS and run bochs.
• Finally, bochs will read the bochsrc.txt file present in this directory and use its contents to load in the file automatically. If for whatever reason it doesn't, you will see a Bochs Configuration: Main Menu screen in the terminal. From here, type 2 for Read options from... and type [Enter] or bochsrc.txt (Bochs will recognize both as bochsrc.txt), then type [Enter] or 6 for Begin simulation (Bochs will recognize both as 6).
  There we go! Bochs has loaded in our operating system! Now, all that is left to do is run it!
• In the event you get a Bochs PANIC message, don't.. panic.. (haha) and just type cont to continue
• In the event you get dropped into a Bochs debug shell, and aren't debugging this operating system, type c to finally run Bochs and see the operating system in action!

Clean Up

Once finished, run make clean to clean the directories of any files that aren't source code.

How it Works

This operating system boots in 16-bit Real Mode, uses BIOS interrupts to read the operating system from disk, loading it into memory address 0x1000 before loading in the GDT to the CPU, switching to 32-bit Protected Mode before, finally, jumping to the kernel where we set the ISR's and IRQ's to currently handle timer and keyboard events.

What It Does

This operating system can't do much yet, but some things it can do are as follows:

• print messages to screen
• read keyboard
• respond to user input
• very crude memory implementations

Planning On Next

I intend to improve the way malloc works. I also intend to implement a simple file system in which the operating system can access. From there, we can make a very basic operating system that can write, read, execute, and load files that can serve as an old 1980's personal computer.