Device Driver Tutorial

Defining the Module Information Entry Point

The _info(9E) routine returns type int and takes an argument that is a pointer to an opaque modinfo structure. The _info(9E) routine must return the value that is returned by the mod_info(9F) function.

The mod_info(9F) function takes two arguments. The first argument to mod_info(9F) is a modlinkage(9S) structure. See Defining the Module Linkage Structures for information about the modlinkage(9S) structure. The second argument to mod_info(9F) is the same modinfo structure pointer that is the argument to the _info(9E) routine. The mod_info(9F) function returns the module information or returns zero if an error occurs.

Use the cmn_err(9F) function to write a message to the system log in the same way that you used the cmn_err(9F) function in your _init(9E) entry point.

The following code is the _info(9E) routine that you should enter into your dummy.c file. The ml structure is discussed in Defining the Module Linkage Structures. The modinfop argument is a pointer to an opaque structure that the system uses to pass module information.

_info(struct modinfo *modinfop)
    cmn_err(CE_NOTE, "Inside _info");
    return(mod_info(&ml, modinfop));