Services are an abstraction of ports and are the commonly used way of inter-process communication outside of the kernel. While handles of regular ports are retrieved from SVC(svcConnectToPort), service handles are retrieved through the port srv: ("service manager").
When a service is registered, svcCreatePort is used without a port-name. This means that the port is inaccessible via the port SVCs outside of sm-module. See below for getting a session handle for sending commands to services.
Processes with PID less than or equal to the number of NATIVE_FIRM built-in modules (fs, sm, pm, pxi, ldr) have access to all services. This value is obtained from svcGetSystemInfo.
Attempting to use srvGetServiceSession with a service that the process has access to when that service isn't registered, results in svcSendSyncRequest never returning(the exact cause is unknown).
Service Manager Port "srv:"
| Command Header | Description |
|---|---|
| 0x00010002 | Initialize |
| 0x00020000 | GetProcSemaphore() (the handle from this gets signaled when notifications for this process gets triggered) |
| 0x00030100 | RegisterService(8-byte servicename, u32 strlen, u32 max_sessions) |
| 0x000400C0 | UnregisterService(8-byte servicename, u32 strlen) |
| 0x00050100 | GetServiceSession(8-byte servicename, u32 strlen, u32 flags)
Flags bit0: if not set, return port-handle instead of session-handle(from svcCreateSessionToPort) when session-handle unavailable (max sessions/timeout?). |
| 0x000600C2 | RegisterPort(8-byte servicename, u32 strlen, Handle client_port) |
| 0x000700C0 | UnregisterPort(8-byte servicename, u32 strlen) |
| 0x00080100 | GetPort(8-byte servicename, u32 strlen, u32 flags).
Flags bit0: return 0 instead of port handle if port was found. |
| 0x00090040 | Subscribe(u32 notification_id). This enables the specified notificationID for the current process. |
| 0x000A0040 | Unsubscribe(u32 notification_id). This disables the specified notificationID for the current process. |
| 0x000B0000 | ReceiveNotification() This returns the notificationID which was triggered, if any(see GetProcSemaphore). |
| 0x000C0080 | PublishToSubscriber(u32 notification_id, u32 flag). This fires an notification. Bit0: only fire if not already fired, bit1: return error if error happens, else it always returns 0. |
| 0x000D0040 | This can fire notificationIDs and return the number of fired notificationID |
| 0x000E00C0 | HasAccessToService(8-byte servicename, u32 strlen). Returns 1 if your process has access to the service. |
Service Manager Process-Manager Port "srv:pm"
| Command Header, prior to 7.0.0-13 | Description |
|---|---|
| 0x04030082 | RegisterProcess (u32 procid, u32 wordsz, ((wordsz<<16) | 2), serviceaccesscontrol*). |
| 0x04040040 | UnregisterProcess (u32 procid). |
The Register command registers a process with the service-manager, which includes registering the serviceaccesscontrol for the process which normally originates from the exheader.
Prior to to 7.0.0-13, the commands listed for "srv:" were also accessible under this port with the same command-headers. Starting with 7.0.0-13, the "srv:pm" port was changed to a service. With this change, commandIDs for these commands were changed. "srv:pm" was originally vulnerable, this was fixed with 7.0.0-13, see here. Originally any process could use "srv:pm", however starting with 7.0.0-13 only the built-in NATIVE_FIRM sysmodules have access to it. The only system title which uses "srv:pm" is the Process Manager.
Notifications
| ID | Description |
|---|---|
| 0x100 | This indicates that all processes must terminate: power-off, reboot, or FIRM-launch. |
| 0x105 | This indicates that the system is entering sleep mode. |
| 0x108 | error at boot? |
| 0x202 | POWER button pressed |
| 0x204 | This indicates that the HOME button was pressed. |
| 0x205 | HOME button pressed |
| 0x207 | SD card inserted |
| 0x208 | Game cartridge inserted |
| 0x209 | SD card removed |
| 0x20A | Game cartridge removed |
| 0x20B | Game cartridge inserted or removed |