QuarkPlatformPkg/Library/PlatformSecureLib/PlatformSecureLib.c

   1 /** @file
   2 Provides a secure platform-specific method to detect physically present user.
   3
   4 Copyright (c) 2013 - 2016 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_INFO, "CheckResetButtonState(): mPlatformType == %d\n", mPlatformType));
  43   if (mPlatformType == GalileoGen2) {
  44     //
  45     // Read state of Reset Button - EXP2.P1_7
  46     // This GPIO is pulled high when the button is not pressed
  47     // This GPIO reads low when button is pressed
  48     //
  49     return PlatformPcal9555GpioGetState (
  50       GALILEO_GEN2_IOEXP2_7BIT_SLAVE_ADDR,  // IO Expander 2.
  51       15                                    // P1-7.
  52       );
  53   }
  54   if (mPlatformType == Galileo) {
  55     //
  56     // Detect the I2C Slave Address of the GPIO Expander
  57     //
  58     if (PlatformLegacyGpioGetLevel (R_QNC_GPIO_RGLVL_RESUME_WELL, GALILEO_DETERMINE_IOEXP_SLA_RESUMEWELL_GPIO)) {
  59       I2CSlaveAddress.I2CDeviceAddress = GALILEO_IOEXP_J2HI_7BIT_SLAVE_ADDR;
  60     } else {
  61       I2CSlaveAddress.I2CDeviceAddress = GALILEO_IOEXP_J2LO_7BIT_SLAVE_ADDR;
  62     }
  63     DEBUG ((EFI_D_INFO, "Galileo GPIO Expender Slave Address = %02x\n", I2CSlaveAddress.I2CDeviceAddress));
  64
  65     //
  66     // Read state of RESET_N_SHLD (GPORT5_BIT0)
  67     //
  68     Buffer[1] = 5;
  69     Length = 1;
  70     ReadLength = 1;
  71     Status = I2cReadMultipleByte (
  72                I2CSlaveAddress,
  73                EfiI2CSevenBitAddrMode,
  74                &Length,
  75                &ReadLength,
  76                &Buffer[1]
  77                );
  78     ASSERT_EFI_ERROR (Status);
  79
  80     //
  81     // Return the state of GPORT5_BIT0
  82     //
  83     return ((Buffer[1] & BIT0) != 0);
  84   }
  85   return TRUE;
  86 }
  87
  88 /**
  89
  90   This function provides a platform-specific method to detect whether the platform
  91   is operating by a physically present user.
  92
  93   Programmatic changing of platform security policy (such as disable Secure Boot,
  94   or switch between Standard/Custom Secure Boot mode) MUST NOT be possible during
  95   Boot Services or after exiting EFI Boot Services. Only a physically present user
  96   is allowed to perform these operations.
  97
  98   NOTE THAT: This function cannot depend on any EFI Variable Service since they are
  99   not available when this function is called in AuthenticateVariable driver.
 100
 101   @retval  TRUE       The platform is operated by a physically present user.
 102   @retval  FALSE      The platform is NOT operated by a physically present user.
 103
 104 **/
 105 BOOLEAN
 106 EFIAPI
 107 UserPhysicalPresent (
 108   VOID
 109   )
 110 {
 111   EFI_STATUS  Status;
 112
 113   //
 114   // If user has already been detected as present, then return TRUE
 115   //
 116   if (PcdGetBool (PcdUserIsPhysicallyPresent)) {
 117     return TRUE;
 118   }
 119
 120   //
 121   // Check to see if user is present now
 122   //
 123   if (CheckResetButtonState ()) {
 124     //
 125     // User is still not present, then return FALSE
 126     //
 127     return FALSE;
 128   }
 129
 130   //
 131   // User has gone from not present to present state, so set
 132   // PcdUserIsPhysicallyPresent to TRUE
 133   //
 134   Status = PcdSetBoolS (PcdUserIsPhysicallyPresent, TRUE);
 135   ASSERT_EFI_ERROR (Status);
 136
 137   return TRUE;
 138 }
 139
 140 /**
 141   Determines if a user is physically present by reading the reset button state.
 142
 143   @param  ImageHandle  The image handle of this driver.
 144   @param  SystemTable  A pointer to the EFI System Table.
 145
 146   @retval EFI_SUCCESS   Install the Secure Boot Helper Protocol successfully.
 147
 148 **/
 149 EFI_STATUS
 150 EFIAPI
 151 PlatformSecureLibInitialize (
 152   IN EFI_HANDLE        ImageHandle,
 153   IN EFI_SYSTEM_TABLE  *SystemTable
 154   )
 155 {
 156   EFI_STATUS  Status;
 157
 158   //
 159   // Get the platform type
 160   //
 161   mPlatformType = (EFI_PLATFORM_TYPE)PcdGet16 (PcdPlatformType);
 162
 163   //
 164   // Read the state of the reset button when the library is initialized
 165   //
 166   Status = PcdSetBoolS (PcdUserIsPhysicallyPresent, !CheckResetButtonState ());
 167   ASSERT_EFI_ERROR (Status);
 168
 169   return EFI_SUCCESS;
 170 }