These are the base MiG code numbers for each subsystem in the GNU Hurd. Each subsystem takes 200 in space. Subsystems marked with a * are Mach kernel subsystems. Subsystems marked with ? may or may not be used in the Hurd and are defined by Mach non-kernel source. * notify 64 IPC notifications * mach 2000 Generic kernel calls * memory_object 2200 Kernel -> pager calls * memory_object_default 2250 Extension to memory_object for default pager ? default_pager 2275 Default pager control * exc 2400 Exceptions * mach_host 2600 Kernel calls, mostly for multiprocessors * device 2800 Physical device interface * mach_debug 3000 Kernel debugging and statistics * mach_port 3200 Port name and IPC frobbing * mach4 4000 PC sampling fs 20000 Filesystem nodes fs_notify 20500 Notification callbacks from fs servers to their clients io 21000 Generic IO fsys 22000 Filesystem control operations msg 23000 Calls made on process message ports process 24000 Process abstraction auth 25000 Authentication socket 26000 Sockets newterm 27000 Creation of terminal processing thingies term 28000 Terminal-specific operations startup 29000 System initialization and destruction startup_notify 29500 Callbacks from startup server exec 30000 Process execution exec_startup 30500 Process startup communication crash 32000 Program crash handling (core dumps) intr 33000 Interruption ifsock 34000 S_IFSOCK node protocol for AF_LOCAL rendezvous tape 35000 Special control operations for magtapes login 36000 Database of logged-in users pfinet 37000 Internet configuration calls password 38000 Password checker hurd_port 39000 Port debugging and introspection 100000- First subsystem of ioctl class 'f' (lowest class) tioctl 156000 Ioctl class 't' (terminals) tioctl 156200 (continued) 164200 Last subsystem of ioctl class 'v' (highest class) * mach_norma 555000 NORMA machine additions; sort of deprecated right now * norma_task 666000 NORMA remote execution ? dp_helper 888888 pager -> fileserver; asking for more paging space