boardctl() Application Interface

int boardctl(unsigned int cmd, uintptr_t arg)

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 direct IOCTL-like calls to the board-specific logic. It is especially useful for setting up board operational and test configurations.

NOTE: The other interfaces described in this document are internal OS interface. boardctl() is an application interface to the OS. There is no point, in fact, of using boardctl() within the OS; the board interfaces prototyped in include/nuttx/board.h may be called directly from within the OS.

Application interfaces are described in the NuttX User Guide. This application interface interface is described here only because it is so non-standard and because it is so closely tied to board porting logic.

Parameters:

• cmd – Identifies the board command to be executed. See include/sys/boardctl.h for the complete list of common board commands. Provisions are made to support non-common, board-specific commands as well.

• arg – The argument that accompanies the command. The nature of the argument is determined by the specific command.

Returns:

On success zero (OK) is returned; -1 (ERROR) is returned on failure with the errno variable set to indicate the nature of the failure.