1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2023 George V. Neville-Neil 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 /* 30 * SKEL Loadable Kernel Module for the FreeBSD Operating System 31 * 32 * The SKEL module is meant to act as a skeleton for creating new 33 * kernel modules. 34 * 35 * This module can be loaded and unloaded from * FreeBSD and is for 36 * use in teaching as well. 37 * 38 */ 39 40 #include <sys/param.h> 41 #include <sys/kernel.h> 42 #include <sys/systm.h> 43 #include <sys/module.h> 44 45 /* 46 * Every module can have a module specific piece of code that is 47 * executed whenever the module is loaded or unloaded. The following 48 * is a trivial example that prints a message on the console whenever 49 * the module is loaded or unloaded. 50 */ 51 52 static int 53 skel_mod_event(module_t mod, int type, void *data) 54 { 55 56 switch (type) { 57 case MOD_LOAD: 58 printf("SKEL module loading.\n"); 59 return (0); 60 case MOD_UNLOAD: 61 printf("SKEL module unloading.\n"); 62 return (0); 63 } 64 return (EOPNOTSUPP); 65 } 66 67 /* 68 * Modules can have associated data and the module data also contains 69 * an entry for the function called by the kernel on load and unload. 70 */ 71 72 static moduledata_t skel_mod = { 73 "skel", 74 skel_mod_event, 75 NULL, 76 }; 77 78 /* 79 * Each module is declared with its name and module data. The 80 * ordering arguments at the end put this module into the device 81 * driver class, which is sufficient for our needs. The complete list 82 * of modules types and ording can be found in sys/kernel.h 83 */ 84 85 DECLARE_MODULE(skel, skel_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE); 86 87