hello everybody!

I'm here again with my new project. it's called HighOS, so you see it's the following OS for LowOS. of course it's in PM. i already wrote a bootloader loading the kernel, switching into the PM and jumping to the kernel. now there are different things:

1. why can't i load the kernel to 0x0000:0x0000 in RM? i don't need the bios-ints after loading it.
2. how can i make memory protection? i load the kernel into a segment where only privileglevel-0-programms can access. but i've got the problem that i don't know how to protect the programms from themselves. they are all in privileglevel-3-codesegments, so they might access other datasegments.

thanks for help

J!N

1. The IRQs call on that range, its implicit. In PM at least you can rellocate, in RM I _think_ this is not possible.
2. Segments? If you use paging you can assign physical pages to process' address space. The page descriptors don't allow a process to access a page not in address space. With segmentation you can achieve semelhant results, but its bit harder, refer to Intel manual volume 3.

#1 - you need the ints while loading, unless you're programming the FDD directly. It's a good idea to save the RM IDT anyway, as you might want v86 mode later. It's only 1k anyway.

#2 - forget about segments, and use paging.

thank you very much!