Services

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").

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.

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 flags?)
0x000400C0	UnregisterService (8-byte servicename, u32 strlen)
0x00050100	GetServiceHandle (8-byte servicename, u32 strlen, u32 flags?)
0x000600c2	RegisterHandle? (8-byte servicename, u32 strlen, Handle h)
0x0007....	UnregisterHandle? (8-byte servicename, u32 strlen)
0x0008....	IsHandlePresent (8-byte servicename, u32 strlen,u32 flags) if flag is set it returns the handle?
0x00090040	Subscribe () This enables the specified notificationID for the current process.
0x000A0040	This disables the specified notificationID for the current process (u32 ID)
0x000B0000	ReceiveNotification This returns the notificationID which was triggered, if any(see GetProcSemaphore).
0x000C0080	PublishToSubscriber(u32 ID,u32 flag) This can fire notificationID (Bit(0) only fire if not already fired, Bit(1) = return error if error happens, else it always returns 0)
0x000D....	This can fire notificationIDs and return the number of fired notificationID
0x000E....	returns 1 if the service is registered. 0 if not (8-byte servicename, u32 strlen)

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.
0x108	error at boot?
0x204	This indicates that the HOME button was pressed.