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 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. Other processes are limited to access services listed in their service access control list, as passed to SRVPM:RegisterProcess.

Attempting to use GetServiceSession 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	RegisterClient
0x00020000	EnableNotification
0x00030100	RegisterService
0x000400C0	UnregisterService
0x00050100	GetServiceHandle
0x000600C2	RegisterPort
0x000700C0	UnregisterPort
0x00080100	GetPort
0x00090040	Subscribe
0x000A0040	Unsubscribe
0x000B0000	ReceiveNotification
0x000C0080	PublishToSubscriber
0x000D0040	PublishAndGetSubscriber
0x000E00C0	IsServiceRegistered

It appears these "port" commands can be used for transferring arbitrary handles, however GetPort still uses service-access-control validation like GetServiceHandle.

Service Manager Process-Manager Port/Service "srv:pm"

Command Header (port), prior to 7.0.0-13	Command Header (service), post 7.0.0-13	Description
0x04010042	0x00010042	PublishToProcess
0x04020040	0x00020040	PublishToAll
0x04030082	0x00030082	RegisterProcess
0x04040040	0x00040040	UnregisterProcess

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.
0x103	Unknown. Subscribed to by AC module (likely to be related to sleep mode as it is called after 0x104 and before 0x105)
0x104	This indicates that the system is entering sleep mode. (PTM:NotifySleepPreparationComplete needed for this and the following?)
0x105	This indicates that the system has exited sleep mode.
0x106	Unknown. Subscribed to by AC module
0x107	Unknown. Subscribed to by CECD module.
0x108	error at boot?
0x109	? (Subscribed to by GSP)
0x10C	Unknown.
0x110-0x11F	Unknown. See PM launch flags.
0x179	Unknown.
0x202	POWER button pressed
0x203	POWER button held long
0x204	HOME button pressed
0x205	HOME button released
0x206	This is signaled by NWMEXT:ControlWirelessEnabled and when the physical Wi-Fi slider is enabled
0x207	SD card inserted
0x208	Game cartridge inserted
0x209	SD card removed
0x20A	Game cartridge removed
0x20B	Game cartridge inserted or removed
0x20C	mcu-module publishes this on a (fatal) hardware condition?, ptm throws fatal error F960D407 in receipt of this
0x20D	? (Subscribed to by GSP)
0x20E	? (Subscribed to by GSP)
0x213	? (Subscribed to by GSP)
0x214	? (Subscribed to by GSP)
0x302	Unknown. Signaled by nwm/AC module.
0x303	Unknown. Subscribed to by CECD module.
0x304	Unknown. Subscribed to by CECD module.