1 /** @file
2 SMM Services Table Library.
3
4 Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php.
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 **/
14
15 #include <PiSmm.h>
16 #include <Protocol/SmmBase2.h>
17 #include <Library/SmmServicesTableLib.h>
18 #include <Library/DebugLib.h>
19
20 EFI_SMM_SYSTEM_TABLE2 *gSmst = NULL;
21
22 /**
23 The constructor function caches the pointer of SMM Services Table.
24
25 @param ImageHandle The firmware allocated handle for the EFI image.
26 @param SystemTable A pointer to the EFI System Table.
27
28 @retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.
29
30 **/
31 EFI_STATUS
32 EFIAPI
SmmServicesTableLibConstructor(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)33 SmmServicesTableLibConstructor (
34 IN EFI_HANDLE ImageHandle,
35 IN EFI_SYSTEM_TABLE *SystemTable
36 )
37 {
38 EFI_STATUS Status;
39 EFI_SMM_BASE2_PROTOCOL *InternalSmmBase2;
40
41 InternalSmmBase2 = NULL;
42 //
43 // Retrieve SMM Base2 Protocol, Do not use gBS from UefiBootServicesTableLib on purpose
44 // to prevent inclusion of gBS, gST, and gImageHandle from SMM Drivers unless the
45 // SMM driver explicity declares that dependency.
46 //
47 Status = SystemTable->BootServices->LocateProtocol (
48 &gEfiSmmBase2ProtocolGuid,
49 NULL,
50 (VOID **)&InternalSmmBase2
51 );
52 ASSERT_EFI_ERROR (Status);
53 ASSERT (InternalSmmBase2 != NULL);
54
55 //
56 // We are in SMM, retrieve the pointer to SMM System Table
57 //
58 InternalSmmBase2->GetSmstLocation (InternalSmmBase2, &gSmst);
59 ASSERT (gSmst != NULL);
60
61 return EFI_SUCCESS;
62 }
63
64 /**
65 This function allows the caller to determine if the driver is executing in
66 System Management Mode(SMM).
67
68 This function returns TRUE if the driver is executing in SMM and FALSE if the
69 driver is not executing in SMM.
70
71 @retval TRUE The driver is executing in System Management Mode (SMM).
72 @retval FALSE The driver is not executing in System Management Mode (SMM).
73
74 **/
75 BOOLEAN
76 EFIAPI
InSmm(VOID)77 InSmm (
78 VOID
79 )
80 {
81 //
82 // We are already in SMM
83 //
84 return TRUE;
85 }
86