OSDev.org

Hello everyone!

I am facing an interesting problem. In short: I have function A and B. When Calling B from inside A my code stops the execution and nothing happens from that point on. A is called from kmain() function (yes I am saving the world and writing yet another OS ) I have no idea why that happens.

The line that 'breaks' my code is at line 44 here
https://github.com/fenistil/ToyToyOS/bl ... nel/scrn.c

If I comment it out like it is now on the git website, bochs has no trouble running it. Seems to be working the way I want it to work. I compile the c file with these options:

-c -g3 -Wall -Wextra -Werror -nostdlib -nostartfiles -nodefaultlibs -I./include

Any help would be appreciated

Try setting up a GDT with a flat address space, the multiboot specification recommends that the kernel set up its own GDT as soon as possible.

Assuming you tried rebuilding everything, the obvious thing to check is the stack: can you tell exactly what part of memory it is supposed to use, and then what the actual value of ESP and EBP is?

A solution is to move the function definitions above the line of the calling function. Even tho I have included a header file that contains the declarations the function call halts. I suppose it could be cause of faulty stack or not set up GDT. I'll get back to this problem once I have facilities to check the stack's value and as well the contents of the registers.