NS and APT Services
The NS system module is the first module launched from a CTR-NAND title after the FIRM processes are loaded. This module is launched by the pm process, with the titleID loaded from NSTID. NS first launches ErrDisp, then the menu. On retail the menu TID is loaded from MENUTID, while on dev/debug the menu TID is loaded from config. On dev-units if the menu TID block doesn't exist in config, NS will attempt to launch the alternate menu instead. The TID of the launched menu is then written to ACTIVEMENUTID. NS uses pm:app to launch titles.
Like home menu NS is constantly running while the system is in 3DS-mode.
When launching the regular menu fails, NS will then attempt to launch the alternate menu. This title could be used as a recovery process, however it's normally not used after the factory. This title is used at the factory for installing system titles, this title seems to be installed from a factory gamecard. This installer title likely deletes itself from NAND once it's finished installing titles.
NS Workaround
A "ns_workaround" was added in NS to workaround the flaw added with 5.0.0-11. When NS is loading before launching any ARM11 processes and certain Configuration Memory flags are set, NS will launch AM then use command AM:InstallNATIVEFIRM. NS will then use PMApp command 0x0009XXXX, then "ptm:sysm" service command 0x04090080.
Therefore, with 5.1.0-11 every time the system boots when the Configuration Memory flags checked by NS are set, with the system will install FIRM from the CTR-NAND NATIVE_FIRM title to the FIRM NAND partitions.
NS Service "ns:s"
| Command Header | Description |
|---|---|
| 0x0001.... | ? |
| 0x000200C0 | LaunchTitle |
| 0x0003.... | ? |
| 0x0004.... | ? |
| 0x0005.... | ? |
| 0x00060042 | ? |
| 0x00070042 | ? |
| 0x0008.... | ? |
| 0x0009.... | ? |
| 0x000A.... | ? |
| 0x000B.... | ? |
| 0x000C.... | ? |
| 0x000D.... | ? |
| 0x000E.... | ? |
| 0x000F.... | ? |
| 0x0010.... | ? |
| 0x0011.... | TerminateProcessTID |
The maximum sessions that can be used with this service is two, therefore only two processes can use this service at the same time.
APT Service "APT:U"
| Command Header | Description |
|---|---|
| 0x00010040 | GetLockHandle |
| 0x00020080 | Initialize |
| 0x00030040 | Enable |
| 0x00040040 | Finalize |
| 0x00050040 | GetAppletManInfo |
| 0x00060040 | GetAppletInfo |
| 0x00070000 | GetLastSignaledAppletId |
| 0x00080000 | CountRegisteredApplet |
| 0x00090040 | IsRegistered |
| 0x000A0040 | GetAttribute |
| 0x000B0040 | InquireNotification |
| 0x000C0104 | SendParameter |
| 0x000D0080 | ReceiveParameter |
| 0x000E0080 | GlanceParameter |
| 0x000F0100 | CancelParameter |
| 0x001000c2 | DebugFunc |
| 0x001100C0 | MapProgramIdForDebug |
| 0x00120040 | SetHomeMenuAppletIdForDebug |
| 0x00130000 | GetPreparationState |
| 0x00140040 | SetPreparationState |
| 0x00150140 | PrepareToStartApplication |
| 0x00160040 | PreloadLibraryApplet |
| 0x00170040 | FinishPreloadingLibraryApplet |
| 0x00180040 | PrepareToStartLibraryApplet |
| 0x00190040 | PrepareToStartSystemApplet |
| 0x001A0000 | PrepareToStartNewestHomeMenu |
| 0x001B00C4 | StartApplication |
| 0x001C0000 | WakeupApplication |
| 0x001D0000 | CancelApplication |
| 0x001E0084 | StartLibraryApplet |
| 0x001F0084 | StartSystemApplet |
| 0x00200044 | StartNewestHomeMenu |
| 0x00210000 | OrderToCloseApplication |
| 0x00220040 | PrepareToCloseApplication |
| 0x00230040 | PrepareToJumpToApplication |
| 0x00240044 | JumpToApplication |
| 0x002500C0 | PrepareToCloseLibraryApplet |
| 0x00260000 | PrepareToCloseSystemApplet |
| 0x00270044 | CloseApplication |
| 0x00280044 | CloseLibraryApplet |
| 0x00290044 | CloseSystemApplet |
| 0x002A0000 | OrderToCloseSystemApplet |
| 0x002B0000 | PrepareToJumpToHomeMenu |
| 0x002C0044 | JumpToHomeMenu |
| 0x002D0000 | PrepareToLeaveHomeMenu |
| 0x002E0044 | LeaveHomeMenu |
| 0x002F0040 | PrepareToLeaveResidentApplet |
| 0x00300044 | LeaveResidentApplet |
| 0x00310100 | PrepareToDoApplicationJump |
| 0x00320084 | DoApplicationJump |
| 0x00330000 | GetProgramIdOnApplicationJump |
| 0x00340084 | SendDeliverArg |
| 0x00350080 | ReceiveDeliverArg |
| 0x00360040 | LoadSysMenuArg |
| 0x00370042 | StoreSysMenuArg |
| 0x00380040 | PreloadResidentApplet |
| 0x00390040 | PrepareToStartResidentApplet |
| 0x003A0044 | StartResidentApplet |
| 0x003B0040 | CancelLibraryApplet |
| 0x003C0042 | SendDspSleep |
| 0x003D0042 | SendDspWakeUp |
| 0x003E0080 | ReplySleepQuery |
| 0x003F0040 | ReplySleepNotificationComplete |
| 0x00400042 | SendCaptureBufferInfo |
| 0x00410040 | ReceiveCaptureBufferInfo |
| 0x00420080 | SleepSystem |
| 0x00430040 | NotifyToWait |
| 0x00440000 | GetSharedFont |
| 0x00450040 | GetWirelessRebootInfo |
| 0x00460104 | Wrap |
| 0x00470104 | Unwrap |
| 0x00480100 | GetProgramInfo |
| 0x00490180 | Reboot |
| 0x004A0040 | GetCaptureInfo |
| 0x004B00C2 | AppletUtility |
| 0x004C0000 | SetFatalErrDispMode |
| 0x004D0080 | GetAppletProgramInfo |
| 0x004E0000 | HardwareResetAsync |
These applet services can handle launching "applets", APT:U handles signaling for home/power button as well.