-Processes can specify if they can run as kernel-mode or user-mode or both -Services are normal processes except that they export services as well as import them kernel: -bootup from multiboot to arbiterd --parse multiboot --change into protected mode --starts arbiterd -single-threaded arbiterd: -runs as root -runs for entire time the os is online -connects processes to services -multi-threaded -when asked for a services, returns a list of services if more than one of that type available, default should be number 0 in that list -creates processes and has complete control over them and their address space arbiterd: -creates processes -manages user-level protection fsd: -allows access to filesystem -connects processes to services (services mounted into filesystem) -process connects to a file (object) and sends messages to it --read and write messages for normal files --custom messages for other files arbiterd: -started by kernel at bootup -executes init scripts, which loads various services -starts processes -manages users -passes port to filesystem root to process /proc/123/environment/ == the processes // tree mount -t blabla //block/ide/0/0 / mount -t blabla /something/image.img /myimage -process gets passed a port to its import device filesystem -filesystem goes like so: --/sockets/ returns list of local sockets use // and /