MdeModulePkg/Universal/PlatformDriverOverride/PlatformDriOverrideDxe/PlatformDriOverride.c

   1 /** @file
   2
   3 Copyright (c) 2007 - 2008, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 **/
  13
  14 #include <Uefi.h>
  15
  16 #include <Library/BaseLib.h>
  17 #include <Library/DebugLib.h>
  18 #include <Library/UefiDriverEntryPoint.h>
  19 #include <Library/UefiBootServicesTableLib.h>
  20 #include <Library/PlatDriOverLib.h>
  21 #include <Protocol/PlatformDriverOverride.h>
  22
  23 LIST_ENTRY      mMappingDataBase = INITIALIZE_LIST_HEAD_VARIABLE (mMappingDataBase);
  24 BOOLEAN         mEnvironmentVariableRead = FALSE;
  25 EFI_HANDLE      mCallerImageHandle = NULL;
  26
  27 /**
  28   Retrieves the image handle of the platform override driver for a controller in the system.
  29
  30   @param  This                   A pointer to the
  31                                  EFI_PLATFORM_DRIVER_OVERRIDE_PROTOCOL instance.
  32   @param  ControllerHandle       The device handle of the controller to check if a
  33                                  driver override exists.
  34   @param  DriverImageHandle      On input, a pointer to the previous driver image
  35                                  handle returned by GetDriver().  On output, a
  36                                  pointer to the next driver image handle. Passing
  37                                  in a NULL,  will return the first driver image
  38                                  handle for ControllerHandle.
  39
  40   @retval EFI_SUCCESS            The driver override for ControllerHandle was
  41                                  returned in DriverImageHandle.
  42   @retval EFI_NOT_FOUND          A driver override for ControllerHandle was not
  43                                  found.
  44   @retval EFI_INVALID_PARAMETER  The handle specified by ControllerHandle is not a
  45                                  valid handle. DriverImageHandle is not a handle
  46                                  that was returned on a previous  call to
  47                                  GetDriver().
  48
  49 **/
  50 EFI_STATUS
  51 EFIAPI
  52 GetDriver (
  53   IN EFI_PLATFORM_DRIVER_OVERRIDE_PROTOCOL              *This,
  54   IN     EFI_HANDLE                                     ControllerHandle,
  55   IN OUT EFI_HANDLE                                     *DriverImageHandle
  56   )
  57 {
  58   EFI_STATUS  Status;
  59
  60   //
  61   // Check that ControllerHandle is a valid handle
  62   //
  63   if (ControllerHandle == NULL) {
  64     return EFI_INVALID_PARAMETER;
  65   }
  66
  67   //
  68   // Read the environment variable(s) that contain the override mappings from Controller Device Path to
  69   // a set of Driver Device Paths, and  initialize in memory database of the overrides that map Controller
  70   // Device Paths to an ordered set of Driver Device Paths and Driver Handles. This action is only performed
  71   // once and finished in first call.
  72   //
  73   if (!mEnvironmentVariableRead) {
  74     mEnvironmentVariableRead = TRUE;
  75
  76     Status = InitOverridesMapping (&mMappingDataBase);
  77     if (EFI_ERROR (Status)){
  78       DEBUG ((DEBUG_ERROR, "The status to Get Platform Driver Override Variable is %r\n", Status));
  79       InitializeListHead (&mMappingDataBase);
  80       return EFI_NOT_FOUND;
  81     }
  82   }
  83
  84   //
  85   // if the environment variable does not exist, just return not found
  86   //
  87   if (IsListEmpty (&mMappingDataBase)) {
  88     return EFI_NOT_FOUND;
  89   }
  90
  91   return GetDriverFromMapping (
  92             ControllerHandle,
  93             DriverImageHandle,
  94             &mMappingDataBase,
  95             mCallerImageHandle
  96             );
  97 }
  98
  99 /**
 100   Retrieves the device path of the platform override driver for a controller in the system.
 101   This driver doesn't support this API.
 102
 103   @param  This                  A pointer to the EFI_PLATFORM_DRIVER_OVERRIDE_
 104                                 PROTOCOL instance.
 105   @param  ControllerHandle      The device handle of the controller to check if a driver override
 106                                 exists.
 107   @param  DriverImageHandle     On input, a pointer to the previous driver image handle returned
 108                                 by GetDriverPath(). On output, a pointer to the next driver
 109                                 device path.
 110
 111   @retval EFI_UNSUPPORTED
 112 **/
 113 EFI_STATUS
 114 EFIAPI
 115 GetDriverPath (
 116   IN EFI_PLATFORM_DRIVER_OVERRIDE_PROTOCOL              *This,
 117   IN     EFI_HANDLE                                     ControllerHandle,
 118   IN OUT EFI_DEVICE_PATH_PROTOCOL                       **DriverImagePath
 119   )
 120 {
 121   return EFI_UNSUPPORTED;
 122 }
 123
 124
 125 /**
 126   Used to associate a driver image handle with a device path that was returned on a prior call to the
 127   GetDriverPath() service. This driver image handle will then be available through the
 128   GetDriver() service. This driver doesn't support this API.
 129
 130   @param  This                  A pointer to the EFI_PLATFORM_DRIVER_OVERRIDE_
 131                                 PROTOCOL instance.
 132   @param  ControllerHandle      The device handle of the controller.
 133   @param  DriverImagePath       A pointer to the driver device path that was returned in a prior
 134                                 call to GetDriverPath().
 135   @param  DriverImageHandle     The driver image handle that was returned by LoadImage()
 136                                 when the driver specified by DriverImagePath was loaded
 137                                 into memory.
 138
 139   @retval EFI_UNSUPPORTED
 140 **/
 141 EFI_STATUS
 142 EFIAPI
 143 DriverLoaded (
 144   IN EFI_PLATFORM_DRIVER_OVERRIDE_PROTOCOL          *This,
 145   IN EFI_HANDLE                                     ControllerHandle,
 146   IN EFI_DEVICE_PATH_PROTOCOL                       *DriverImagePath,
 147   IN EFI_HANDLE                                     DriverImageHandle
 148   )
 149 {
 150   return EFI_UNSUPPORTED;
 151 }
 152
 153 EFI_PLATFORM_DRIVER_OVERRIDE_PROTOCOL mPlatformDriverOverride = {
 154   GetDriver,
 155   GetDriverPath,
 156   DriverLoaded
 157 };
 158
 159 /**
 160   Platform Driver Override driver entry point, install the Platform Driver Override Protocol
 161
 162   @param  ImageHandle  ImageHandle of the loaded driver.
 163   @param  SystemTable  Pointer to the EFI System Table.
 164
 165   @retval  EFI_SUCCESS               The DXE Driver, DXE Runtime Driver, DXE SMM Driver,
 166                                      or UEFI Driver exited normally.
 167   @retval  EFI_ALREADY_STARTED       A protocol instance has been installed. Not need install again.
 168 **/
 169 EFI_STATUS
 170 EFIAPI
 171 PlatformDriverOverrideEntry (
 172   IN EFI_HANDLE        ImageHandle,
 173   IN EFI_SYSTEM_TABLE  *SystemTable
 174   )
 175 {
 176   EFI_HANDLE          Handle;
 177   EFI_STATUS          Status;
 178   VOID                *Instance;
 179
 180   mCallerImageHandle = ImageHandle;
 181
 182   //
 183   // According to UEFI spec, there can be at most a single instance
 184   // in the system of the EFI_PLATFORM_DRIVER_OVERRIDE_PROTOCOL.
 185   // So here we check the existence.
 186   //
 187   Status = gBS->LocateProtocol (
 188                   &gEfiPlatformDriverOverrideProtocolGuid,
 189                   NULL,
 190                   &Instance
 191                   );
 192   //
 193   // If there was no error, assume there is an installation and return error
 194   //
 195   if (!EFI_ERROR (Status)) {
 196     return EFI_ALREADY_STARTED;
 197   }
 198
 199   //
 200   // Install platform driver override protocol
 201   //
 202   Handle = NULL;
 203   Status = gBS->InstallProtocolInterface (
 204                   &Handle,
 205                   &gEfiPlatformDriverOverrideProtocolGuid,
 206                   EFI_NATIVE_INTERFACE,
 207                   &mPlatformDriverOverride
 208                   );
 209   ASSERT_EFI_ERROR (Status);
 210   return EFI_SUCCESS;
 211 }