mdriver_add()

Register the minidriver with the system

Synopsis:

int mdriver_add(char *name,
                int interrupt,
                int (*handler)( int state,
                                void *data), 
                paddr32_t data_paddr, 
                unsigned data_size)

Arguments:

name

An arbitrary character string used for identification purposes.

interrupt

The interrupt that you want to attach to.

handler

A pointer to the handler function for the minidriver. “Handler function” in the Writing a Minidriver chapter.

data_paddr

The physical address of a block of memory that the minidriver can use to store any data. It can be:

• a predetermined location (e.g., one that you reserved beforehand by passing the -r addr,size[,flag] option to startup)
• a block that you allocated by calling the alloc_ram() startup function

The virtual address of this block is passed to the handler function as its data argument.

data_size

The size of the block of memory denoted by data_paddr.

Library:

libc

Description:

This function registers the minidriver with the system, as follows:

• It checks the interrupt number to make sure it's valid, so you must call init_intrinfo() to add the interrupt information to the system page before you can register a minidriver. For more information, see the Customizing Image Startup Programs chapter of Building Embedded Systems.

  ---

  If the interrupt number isn't valid, mdriver_add() crashes the system.

  ---

• It calls the handler with a state of MDRIVER_INIT and the virtual address that corresponds to the physical address given by data_paddr.
• It adds an entry of type mdriver_entry to the mdriver section of the system page.

You call mdriver_add() from main() in your board's startup code.

Returns:

The index into the mdriver section of the system page for the newly added minidriver, or -1 if the minidriver wasn't added.

Classification:

QNX Neutrino

The Safety information below is “Not applicable” because the OS isn't even running when you call mdriver_add().