Basic driver from custom operating system [os]

The Members From Aura-Team and Myself, are developing a custom operating system we have been in development for a few years now and we are looking into adding more advanced graphics, now we have a basic ELF loader for DLL, and some EXE files (com is also supported), but we need information regarding system calls that must be made for a basic driver to work, and some listed structure. Thank you.

[note: I am not a business professional, I am just a team member looking for better and faster graphics.]