libsa/bootstrap.cpp

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 #include <IOKit/IOLib.h>
  26 #include <mach/kmod.h>
  27 #include <libkern/c++/OSDictionary.h>
  28
  29 #include <libsa/kext.h>
  30 #include <libsa/catalogue.h>
  31 #include <libsa/malloc.h>
  32
  33 #include "kld_patch.h"
  34
  35 /*****
  36  * This function is used by IOCatalogue to load a kernel
  37  * extension. libsa initially sets it to be a function
  38  * that uses libkld to load and link the extension from
  39  * within the kernel. Once the root filesystem is up,
  40  * this gets switch to the kmod_load_extension() function,
  41  * which merely queues the extension for loading by the
  42  * kmodload utility.
  43  */
  44 extern kern_return_t (*kmod_load_function)(char *extension_name);
  45 extern bool (*record_startup_extensions_function)(void);
  46 extern bool (*add_from_mkext_function)(OSData * mkext);
  47 extern void (*remove_startup_extension_function)(const char * name);
  48
  49 /****
  50  * IOCatalogue uses this variable to make a few decisions
  51  * about loading and matching drivers.
  52  */
  53 extern int kernelLinkerPresent;
  54
  55
  56 class KLDBootstrap {
  57 public:
  58     KLDBootstrap();
  59     ~KLDBootstrap();
  60 };
  61
  62
  63 static KLDBootstrap bootstrap_obj;
  64
  65
  66 /* The constructor creates a lock and puts entries into a dispatch
  67  * table for functions used to record and load kmods.
  68  */
  69 KLDBootstrap::KLDBootstrap() {
  70
  71     malloc_init();
  72
  73     kmod_load_function = &load_kernel_extension;
  74
  75     record_startup_extensions_function = &recordStartupExtensions;
  76     add_from_mkext_function = &addExtensionsFromArchive;
  77     remove_startup_extension_function = &removeStartupExtension;
  78
  79     kernelLinkerPresent = 1;
  80 }
  81
  82 /* The destructor frees all wired memory regions held
  83  * by libsa's malloc package and disposes of the lock.
  84  */
  85 KLDBootstrap::~KLDBootstrap() {
  86
  87     kld_file_cleanup_all_resources();
  88
  89    /* Dump all device-tree entries for boot drivers, and all
  90     * info on startup extensions. The IOCatalogue will now
  91     * get personalities from kextd.
  92     */
  93     clearStartupExtensionsAndLoaderInfo();
  94
  95    /* Free all temporary malloc memory.
  96     */
  97     malloc_reset();
  98 }