2 Produce the memory type information HOB.
4 Copyright (C) 2017-2020, Red Hat, Inc.
6 SPDX-License-Identifier: BSD-2-Clause-Patent
9 #include <Guid/MemoryTypeInformation.h>
10 #include <Library/BaseLib.h>
11 #include <Library/DebugLib.h>
12 #include <Library/HobLib.h>
13 #include <Library/PcdLib.h>
14 #include <Library/PeiServicesLib.h>
15 #include <Ppi/ReadOnlyVariable2.h>
16 #include <Uefi/UefiMultiPhase.h>
20 #define MEMORY_TYPE_INFO_DEFAULT(Type) \
21 { Type, FixedPcdGet32 (PcdMemoryType ## Type) }
23 STATIC EFI_MEMORY_TYPE_INFORMATION mMemoryTypeInformation
[] = {
24 MEMORY_TYPE_INFO_DEFAULT (EfiACPIMemoryNVS
),
25 MEMORY_TYPE_INFO_DEFAULT (EfiACPIReclaimMemory
),
26 MEMORY_TYPE_INFO_DEFAULT (EfiReservedMemoryType
),
27 MEMORY_TYPE_INFO_DEFAULT (EfiRuntimeServicesCode
),
28 MEMORY_TYPE_INFO_DEFAULT (EfiRuntimeServicesData
),
29 { EfiMaxMemoryType
, 0 }
39 &gEfiMemoryTypeInformationGuid
,
40 mMemoryTypeInformation
,
41 sizeof mMemoryTypeInformation
46 Refresh the mMemoryTypeInformation array (which we'll turn into the
47 MemoryTypeInformation HOB) from the MemoryTypeInformation UEFI variable.
49 Normally, the DXE IPL PEIM builds the HOB from the UEFI variable. But it does
50 so *transparently*. Instead, we consider the UEFI variable as a list of
51 hints, for updating our HOB defaults:
53 - Record types not covered in mMemoryTypeInformation are ignored. In
54 particular, this hides record types from the UEFI variable that may lead to
55 reboots without benefiting SMM security, such as EfiBootServicesData.
57 - Records that would lower the defaults in mMemoryTypeInformation are also
60 @param[in] ReadOnlyVariable2 The EFI_PEI_READ_ONLY_VARIABLE2_PPI used for
61 retrieving the MemoryTypeInformation UEFI
67 IN EFI_PEI_READ_ONLY_VARIABLE2_PPI
*ReadOnlyVariable2
71 EFI_MEMORY_TYPE_INFORMATION Entries
[EfiMaxMemoryType
+ 1];
77 // Read the MemoryTypeInformation UEFI variable from the
78 // gEfiMemoryTypeInformationGuid namespace.
80 DataSize
= sizeof Entries
;
81 Status
= ReadOnlyVariable2
->GetVariable (
83 EFI_MEMORY_TYPE_INFORMATION_VARIABLE_NAME
,
84 &gEfiMemoryTypeInformationGuid
,
89 if (EFI_ERROR (Status
)) {
91 // If the UEFI variable does not exist (EFI_NOT_FOUND), we can't use it for
92 // udpating mMemoryTypeInformation.
94 // If the UEFI variable exists but Entries is too small to hold it
95 // (EFI_BUFFER_TOO_SMALL), then the variable contents are arguably invalid.
96 // That's because Entries has room for every distinct EFI_MEMORY_TYPE,
97 // including the terminator record with EfiMaxMemoryType. Thus, we can't
98 // use the UEFI variable for updating mMemoryTypeInformation.
100 // If the UEFI variable couldn't be read for some other reason, we
101 // similarly can't use it for udpating mMemoryTypeInformation.
103 DEBUG ((DEBUG_ERROR
, "%a: GetVariable(): %r\n", __FUNCTION__
, Status
));
108 // Sanity-check the UEFI variable size against the record size.
110 if (DataSize
% sizeof Entries
[0] != 0) {
111 DEBUG ((DEBUG_ERROR
, "%a: invalid UEFI variable size %Lu\n", __FUNCTION__
,
115 NumEntries
= DataSize
/ sizeof Entries
[0];
118 // For each record in mMemoryTypeInformation, except the terminator record,
119 // look up the first match (if any) in the UEFI variable, based on the memory
122 for (HobRecordIdx
= 0;
123 HobRecordIdx
< ARRAY_SIZE (mMemoryTypeInformation
) - 1;
125 EFI_MEMORY_TYPE_INFORMATION
*HobRecord
;
127 EFI_MEMORY_TYPE_INFORMATION
*VariableRecord
;
129 HobRecord
= &mMemoryTypeInformation
[HobRecordIdx
];
131 for (Idx
= 0; Idx
< NumEntries
; Idx
++) {
132 VariableRecord
= &Entries
[Idx
];
134 if (VariableRecord
->Type
== HobRecord
->Type
) {
140 // If there is a match, allow the UEFI variable to increase NumberOfPages.
142 if (Idx
< NumEntries
&&
143 HobRecord
->NumberOfPages
< VariableRecord
->NumberOfPages
) {
144 DEBUG ((DEBUG_VERBOSE
, "%a: Type 0x%x: NumberOfPages 0x%x -> 0x%x\n",
145 __FUNCTION__
, HobRecord
->Type
, HobRecord
->NumberOfPages
,
146 VariableRecord
->NumberOfPages
));
148 HobRecord
->NumberOfPages
= VariableRecord
->NumberOfPages
;
154 Notification function called when EFI_PEI_READ_ONLY_VARIABLE2_PPI becomes
157 @param[in] PeiServices Indirect reference to the PEI Services Table.
158 @param[in] NotifyDescriptor Address of the notification descriptor data
160 @param[in] Ppi Address of the PPI that was installed.
162 @return Status of the notification. The status code returned from this
168 OnReadOnlyVariable2Available (
169 IN EFI_PEI_SERVICES
**PeiServices
,
170 IN EFI_PEI_NOTIFY_DESCRIPTOR
*NotifyDescriptor
,
174 DEBUG ((DEBUG_VERBOSE
, "%a\n", __FUNCTION__
));
176 RefreshMemTypeInfo (Ppi
);
177 BuildMemTypeInfoHob ();
182 // Notification object for registering the callback, for when
183 // EFI_PEI_READ_ONLY_VARIABLE2_PPI becomes available.
185 STATIC CONST EFI_PEI_NOTIFY_DESCRIPTOR mReadOnlyVariable2Notify
= {
186 (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_DISPATCH
|
187 EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST
), // Flags
188 &gEfiPeiReadOnlyVariable2PpiGuid
, // Guid
189 OnReadOnlyVariable2Available
// Notify
193 MemTypeInfoInitialization (
199 if (!FeaturePcdGet (PcdSmmSmramRequire
)) {
201 // EFI_PEI_READ_ONLY_VARIABLE2_PPI will never be available; install
202 // the default memory type information HOB right away.
204 BuildMemTypeInfoHob ();
208 Status
= PeiServicesNotifyPpi (&mReadOnlyVariable2Notify
);
209 if (EFI_ERROR (Status
)) {
210 DEBUG ((DEBUG_ERROR
, "%a: failed to set up R/O Variable 2 callback: %r\n",
211 __FUNCTION__
, Status
));