iokit/Kernel/i386/IOKeyStoreHelper.cpp

   1 /*
   2  * Copyright (c) 2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <sys/cdefs.h>
  30 #include <stdbool.h>
  31
  32 #include <IOKit/assert.h>
  33 #include <IOKit/system.h>
  34 #include <IOKit/IOLib.h>
  35 #include <IOKit/IOMemoryDescriptor.h>
  36 #include <IOKit/IOKitDebug.h>
  37
  38 __BEGIN_DECLS
  39
  40 #include <pexpert/pexpert.h>
  41
  42 static volatile UInt32 alreadyFetched = 0;
  43 static IOMemoryDescriptor * newData;
  44
  45 IOMemoryDescriptor *
  46 IOGetBootKeyStoreData(void);
  47 void
  48 IOSetKeyStoreData(IOMemoryDescriptor * data);
  49
  50 __END_DECLS
  51
  52 #if 1
  53 #define DEBG(fmt, args...)      { kprintf(fmt, ## args); }
  54 #else
  55 #define DEBG(fmt, args...)      {}
  56 #endif
  57
  58 void
  59 IOSetKeyStoreData(IOMemoryDescriptor * data)
  60 {
  61     newData = data;
  62     alreadyFetched = 0;
  63 }
  64
  65 IOMemoryDescriptor *
  66 IOGetBootKeyStoreData(void)
  67 {
  68   IOMemoryDescriptor *memoryDescriptor;
  69   boot_args *args = (boot_args *)PE_state.bootArgs;
  70   IOOptionBits options;
  71   IOAddressRange ranges;
  72
  73   if (!OSCompareAndSwap(0, 1, &alreadyFetched))
  74     return (NULL);
  75
  76   if (newData)
  77   {
  78     IOMemoryDescriptor * data = newData;
  79     newData = NULL;
  80     return (data);
  81   }
  82
  83   DEBG("%s: data at address %u size %u\n", __func__,
  84        args->keyStoreDataStart,
  85        args->keyStoreDataSize);
  86
  87   if (args->keyStoreDataStart == 0)
  88     return (NULL);
  89
  90   ranges.address = args->keyStoreDataStart;
  91   ranges.length = args->keyStoreDataSize;
  92
  93   options = kIODirectionInOut | kIOMemoryTypePhysical64;
  94
  95   memoryDescriptor = IOMemoryDescriptor::withOptions(&ranges,
  96                                                      1,
  97                                                      0,
  98                                                      NULL,
  99                                                      options);
 100
 101   DEBG("%s: memory descriptor %p\n", __func__, memoryDescriptor);
 102
 103   return memoryDescriptor;
 104 }