QuarkPlatformPkg/Library/PlatformSecureLib/PlatformSecureLib.c

   1 /** @file
   2 Provides a secure platform-specific method to detect physically present user.
   3
   4 Copyright (c) 2013 Intel Corporation.
   5
   6 This program and the accompanying materials
   7 are licensed and made available under the terms and conditions of the BSD License
   8 which accompanies this distribution.  The full text of the license may be found at
   9 http://opensource.org/licenses/bsd-license.php
  10
  11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include <PiDxe.h>
  17 #include <Library/PlatformHelperLib.h>
  18 #include <Library/DebugLib.h>
  19 #include <Library/UefiBootServicesTableLib.h>
  20 #include <Library/I2cLib.h>
  21
  22 #include <PlatformBoards.h>
  23 #include <Pcal9555.h>
  24 #include <QNCAccess.h>
  25
  26 //
  27 // Global variable to cache pointer to I2C protocol.
  28 //
  29 EFI_PLATFORM_TYPE mPlatformType = TypeUnknown;
  30
  31 BOOLEAN
  32 CheckResetButtonState (
  33   VOID
  34   )
  35 {
  36   EFI_STATUS              Status;
  37   EFI_I2C_DEVICE_ADDRESS  I2CSlaveAddress;
  38   UINTN                   Length;
  39   UINTN                   ReadLength;
  40   UINT8                   Buffer[2];
  41
  42   DEBUG ((EFI_D_ERROR, "CheckResetButtonState(): mPlatformType == %d\n", mPlatformType));
  43   if (mPlatformType == GalileoGen2) {
  44     //
  45     //  Reset Button - EXP2.P1_7 should be configured as an input.
  46     //
  47     PlatformPcal9555GpioSetDir (
  48       GALILEO_GEN2_IOEXP2_7BIT_SLAVE_ADDR,  // IO Expander 2.
  49       15,                                   // P1-7.
  50       FALSE
  51       );
  52
  53     //
  54     // Reset Button - EXP2.P1_7 pullup should be disabled.
  55     //
  56     PlatformPcal9555GpioDisablePull (
  57       GALILEO_GEN2_IOEXP2_7BIT_SLAVE_ADDR,  // IO Expander 2.
  58       15                                    // P1-7.
  59       );
  60
  61     //
  62     // Read state of Reset Button - EXP2.P1_7
  63     // This GPIO is pulled high when the button is not pressed
  64     // This GPIO reads low when button is pressed
  65     //
  66     return PlatformPcal9555GpioGetState (
  67       GALILEO_GEN2_IOEXP2_7BIT_SLAVE_ADDR,  // IO Expander 2.
  68       15                                    // P1-7.
  69       );
  70   }
  71   if (mPlatformType == Galileo) {
  72     //
  73     // Detect the I2C Slave Address of the GPIO Expander
  74     //
  75     if (PlatformLegacyGpioGetLevel (R_QNC_GPIO_RGLVL_RESUME_WELL, GALILEO_DETERMINE_IOEXP_SLA_RESUMEWELL_GPIO)) {
  76       I2CSlaveAddress.I2CDeviceAddress = GALILEO_IOEXP_J2HI_7BIT_SLAVE_ADDR;
  77     } else {
  78       I2CSlaveAddress.I2CDeviceAddress = GALILEO_IOEXP_J2LO_7BIT_SLAVE_ADDR;
  79     }
  80
  81     //
  82     // Select Port 5
  83     //
  84     Length = 2;
  85     Buffer[0] = 0x18;
  86     Buffer[1] = 0x05;
  87     Status = I2cWriteMultipleByte (
  88                I2CSlaveAddress,
  89                EfiI2CSevenBitAddrMode,
  90                &Length,
  91                &Buffer
  92                );
  93     ASSERT_EFI_ERROR (Status);
  94
  95     //
  96     // Read "Pin Direction" of Port 5
  97     //
  98     Length = 1;
  99     ReadLength = 1;
 100     Buffer[1] = 0x1C;
 101     Status = I2cReadMultipleByte (
 102                I2CSlaveAddress,
 103                EfiI2CSevenBitAddrMode,
 104                &Length,
 105                &ReadLength,
 106                &Buffer[1]
 107                );
 108     ASSERT_EFI_ERROR (Status);
 109
 110     //
 111     // Set "Pin Direction" of Port 5, Bit 0 as input
 112     //
 113     Length = 2;
 114     Buffer[0] = 0x1C;
 115     Buffer[1] = Buffer[1] | BIT0;
 116
 117     Status = I2cWriteMultipleByte (
 118                I2CSlaveAddress,
 119                EfiI2CSevenBitAddrMode,
 120                &Length,
 121                &Buffer
 122                );
 123     ASSERT_EFI_ERROR (Status);
 124
 125     //
 126     // Read Port 5
 127     //
 128     Buffer[1] = 5;
 129     Length = 1;
 130     ReadLength = 1;
 131
 132     Status = I2cReadMultipleByte (
 133                I2CSlaveAddress,
 134                EfiI2CSevenBitAddrMode,
 135                &Length,
 136                &ReadLength,
 137                &Buffer[1]
 138                );
 139     ASSERT_EFI_ERROR (Status);
 140
 141     //
 142     // Return the state of Port 5, Bit 0
 143     //
 144     return ((Buffer[1] & BIT0) != 0);
 145   }
 146   return TRUE;
 147 }
 148
 149 /**
 150
 151   This function provides a platform-specific method to detect whether the platform
 152   is operating by a physically present user.
 153
 154   Programmatic changing of platform security policy (such as disable Secure Boot,
 155   or switch between Standard/Custom Secure Boot mode) MUST NOT be possible during
 156   Boot Services or after exiting EFI Boot Services. Only a physically present user
 157   is allowed to perform these operations.
 158
 159   NOTE THAT: This function cannot depend on any EFI Variable Service since they are
 160   not available when this function is called in AuthenticateVariable driver.
 161
 162   @retval  TRUE       The platform is operated by a physically present user.
 163   @retval  FALSE      The platform is NOT operated by a physically present user.
 164
 165 **/
 166 BOOLEAN
 167 EFIAPI
 168 UserPhysicalPresent (
 169   VOID
 170   )
 171 {
 172   EFI_STATUS  Status;
 173
 174   //
 175   // If user has already been detected as present, then return TRUE
 176   //
 177   if (PcdGetBool (PcdUserIsPhysicallyPresent)) {
 178     return TRUE;
 179   }
 180
 181   //
 182   // Check to see if user is present now
 183   //
 184   if (CheckResetButtonState ()) {
 185     //
 186     // User is still not present, then return FALSE
 187     //
 188     return FALSE;
 189   }
 190
 191   //
 192   // User has gone from not present to present state, so set
 193   // PcdUserIsPhysicallyPresent to TRUE
 194   //
 195   Status = PcdSetBoolS (PcdUserIsPhysicallyPresent, TRUE);
 196   ASSERT_EFI_ERROR (Status);
 197
 198   return TRUE;
 199 }
 200
 201 /**
 202   Determines if a user is physically present by reading the reset button state.
 203
 204   @param  ImageHandle  The image handle of this driver.
 205   @param  SystemTable  A pointer to the EFI System Table.
 206
 207   @retval EFI_SUCCESS   Install the Secure Boot Helper Protocol successfully.
 208
 209 **/
 210 EFI_STATUS
 211 EFIAPI
 212 PlatformSecureLibInitialize (
 213   IN EFI_HANDLE        ImageHandle,
 214   IN EFI_SYSTEM_TABLE  *SystemTable
 215   )
 216 {
 217   EFI_STATUS  Status;
 218
 219   //
 220   // Get the platform type
 221   //
 222   mPlatformType = (EFI_PLATFORM_TYPE)PcdGet16 (PcdPlatformType);
 223
 224   //
 225   // Read the state of the reset button when the library is initialized
 226   //
 227   Status = PcdSetBoolS (PcdUserIsPhysicallyPresent, !CheckResetButtonState ());
 228   ASSERT_EFI_ERROR (Status);
 229
 230   return EFI_SUCCESS;
 231 }