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
CheckResetButtonState(VOID)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
UserPhysicalPresent(VOID)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
PlatformSecureLibInitialize(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)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 }
171