The only image data contained in this sysmodule is basically a saved display framebuffer, no image data for actively-used layers/framebuffers.

mm:u

NVIDIA multimedia (NvMM) platform service.

Cmd	Name
0	?
1	?
2	?
3	?
4	module_init_clk
5	module_deinit_clk
6	module_set_clk_rate
7	module_get_clk_rate

vi:u

This is "nn::visrv::sf::IApplicationRootService".

Cmd	Name	Notes
0	GetDisplayService	Returns an #IApplicationDisplayService. Takes an input u64(?), can be zero.

vi:m

This is "nn::visrv::sf::IManagerRootService".

Cmd	Name	Notes
2	GetDisplayService	Returns an #IApplicationDisplayService.
3	GetDisplayServiceWithProxyNameExchange	Takes an input u64 and u32. Returns an #IApplicationDisplayService.

vi:s

This is "nn::visrv::sf::ISystemRootService".

Cmd	Name
1	GetDisplayService	Returns an #IApplicationDisplayService.
3	GetDisplayServiceWithProxyNameExchange	Returns an #IApplicationDisplayService.

IApplicationDisplayService

Cmd	Name	Notes
100	GetRelayService	Returns an #IHOSBinderDriver.
101	GetSystemDisplayService	Returns an #ISystemDisplayService.
102	GetManagerDisplayService	Returns an #IManagerDisplayService.
103	GetIndirectDisplayTransactionService	Returns an #IHOSBinderDriver.
1000	ListDisplays
1010	OpenDisplay
1011	OpenDefaultDisplay
1020	CloseDisplay
1101	SetDisplayEnabled
1102	GetDisplayResolution
2020	OpenLayer
2021	CloseLayer
2030	CreateStrayLayer
2031	DestroyStrayLayer
2101	SetLayerScalingMode
2450	GetIndirectLayerImageMap
2451	GetIndirectLayerImageCropMap
2460	GetIndirectLayerImageRequiredMemoryInfo
5202	GetDisplayVsyncEvent
5203	GetDisplayVsyncEventForDebug

Available sessions for each service:

"vi:u": Only GetRelayService.
"vi:s": Everything except GetManagerDisplayService.
"vi:m": All.

When attempting to use a get-session cmd with a service it's not available with, error 0xA72 is returned.

ListDisplays

Takes a type-0x6 output buffer containing the array of #DisplayInfo output entries. Returns an output u64: total number of output entries.

Normally(?) this only returns the "Default" display.

OpenDisplay

Takes a #DisplayName as input. Returns an output u64, the DisplayId.

To open the default display, input string "Default" can be used.

OpenDefaultDisplay

Returns an output u64.

Probably not (?) used by newer official user-processes, since those use OpenDisplay with the default string instead.

CloseDisplay

Takes an input u64, DisplayId.

SetDisplayEnabled

Takes an input u32 boolean, and an u64(DisplayId?).

GetDisplayResolution

Takes an input u64 DisplayId and returns two output u64s.

OpenLayer

Takes a PID-descriptor, a type-0x6 buffer for the output #NativeWindow, a #DisplayName(which was previously used with #OpenDisplay), an u64 LayerId, and an u64 AppletResourceUserId. Returns an output u64 NativeWindow_Size.

Official user-processes use a LayerId stored in a global state field("...ExternalLayerId") if non-zero, otherwise:

When AppletResourceUserId==0, #CreateStrayLayer is used instead of the OpenLayer cmd.
When AppletResourceUserId!=0, AM_services#CreateManagedDisplayLayer is used and the output from that is used for LayerId with the OpenLayer cmd.

CloseLayer

Takes an input u64: LayerId which was used with #OpenLayer.

CreateStrayLayer

Takes a type-0x6 buffer for the output #NativeWindow, an u32(LayerFlags bitmask), and an u64 DisplayId. Returns two output u64s: LayerId and NativeWindow_Size.

DestroyStrayLayer

Takes an input u64: LayerId from #CreateStrayLayer.

SetLayerScalingMode

Takes an input u32("ScalingMode") and u64.

GetIndirectLayerImageMap

Takes a PID-descriptor, an type-0x46 buffer, and four u64s: width(s32), height(s32), <output from AM GetIndirectLayerConsumerHandle>, and AppletResourceUserId. Returns two output u64s.

GetIndirectLayerImageCropMap

Takes a PID-descriptor, an type-0x46 buffer, four floats, four u64s(last u64 is AppletResourceUserId). Returns two output u64s. The floats are stored immediately after each other(32bits).

GetIndirectLayerImageRequiredMemoryInfo

Takes two input u64s: with and height. Returns two output u64s. First u64 is the buffer size to use with the ImageMap cmds.

GetDisplayVsyncEvent

Takes an input u64 DisplayId and returns a handle.

GetDisplayVsyncEventForDebug