diff --git a/Documentation/NXGraphicsSubsystem.html b/Documentation/NXGraphicsSubsystem.html index 0c5f3dd356..3a58de35fc 100644 --- a/Documentation/NXGraphicsSubsystem.html +++ b/Documentation/NXGraphicsSubsystem.html @@ -12,7 +12,7 @@

NX Graphics Subsystem

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Last Updated: October 15, 2017

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Last Updated: October 17, 2017

@@ -90,40 +90,47 @@

@@ -921,9 +928,94 @@ struct nx_callback_s }; -

2.3.3 NX Server Callbacks

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2.3.3 Starting the NX Server

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+ The NX Server is a kernel daemon that receives and serializes graphic commands. + Before you can use the NX graphics system, you must first start this daemon. + There are two ways that this can be done: +

+
    +
  1. +

    + The NX server may be started in your board startup logic by simply calling the function nx_start(). + The board startup logic usually resides the the configs/board/src directory. + The boar board startup logic can run automatically during the early system if CONFIG_BOARD_INITIALIZE is defined in the configuration. + Or, the board startup logic can execute under control of the application by calling the boardctl(BOARDIOC_INIT, arg) OS interface. +

    +

    + The board initialization logic will run in either case and the simple call to nx_start() will start the NX server. +

    +
    2. +
  2. + The NX server may also be started later by the application via the boardctl(BOARDIOC_NX_START, arg) +
    3. +
-

2.3.3.1 redraw()

+

2.3.3.1 nx_start()

+

Function Prototype:

+ +

+ Description: + nx_start() provides a wrapper function to simplify and standardize the starting of the NX server. +

+

+ Input Parameters: + None +

+

+ Returned Value: + Zero (OK) is returned on success. + This indicates that the NX server has been successfully started, is running, and waiting to accept connections from NX clients. +

+

+ A negated errno value is returned on failure. + The errno value indicates the nature of the failure. +

+ +

2.3.3.1 boardctl()

+

Function Prototype:

+ +

+ Description: + boardctl() is a generic NuttX interface that among many of it functions, may also be used to start the NX server. +

+ In a small embedded system, there will typically be a much greater interaction between application and low-level board features. + The canonically correct to implement such interactions is by implementing a character driver and performing the interactions via low level ioctl() calls. + This, however, may not be practical in many cases and will lead to "correct" but awkward implementations. +

+

+ boardctl() is non-standard OS interface to alleviate the problem. + It basically circumvents the normal device driver ioctl interlace and allows the application to perform direction IOCTL-like calls to the board-specific logic. + In it is especially useful for setting up board operational and test configurations. +

+

+ When called with the cmd of BOARDIOC_NX_START, then the boardctl() will call nx_start indirectly on behalf of the appication. + In this case the arg parameter is ignored. +

+

+ Input Parameters: +

+

+

+ Returned Value: + On success zero (OKERROR) is returned on failure with the errno variable to to indicate the nature of the failure. +

+ +

2.3.4 NX Server Callbacks

+ +

2.3.4.1 redraw()

Callback Function Prototype: