diff options
| author | Nate DeSimone <nathaniel.l.desimone@intel.com> | 2021-04-02 17:28:45 -0700 |
|---|---|---|
| committer | Nate DeSimone <nathaniel.l.desimone@intel.com> | 2021-04-09 13:05:49 -0700 |
| commit | 6904c932efe550f570784a8a18546d75dba97820 (patch) | |
| tree | 56b54356ac0214508999466afa8fb0747a5ed2e0 | |
| parent | 3c5613cd9bca1639d370f24e4bb83aa9b12d3244 (diff) | |
MinPlatformPkg: Add LargeVariableReadLib
LargeVariableReadLib is used to retrieve large data sets using
the UEFI Variable Services. At time of writting, most UEFI
Variable Services implementations to not allow more than 64KB
of data to be stored in a single UEFI variable. This library
will split data sets across multiple variables as needed.
It adds the GetLargeVariable() API to provide this service.
The primary use for this library is to create binary compatible
drivers and OpROMs which need to work both with TianoCore and
other UEFI PI implementations. When customizing and recompiling
the platform firmware image is possible, adjusting the value of
PcdMaxVariableSize may provide a simpler solution to this
problem.
Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Michael Kubacki <michael.kubacki@microsoft.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>
Signed-off-by: Nate DeSimone <nathaniel.l.desimone@intel.com>
Reviewed-by: Chasel Chiu <chasel.chiu@intel.com>
Reviewed-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Isaac Oram <isaac.w.oram@intel.com>
6 files changed, 338 insertions, 1 deletions
diff --git a/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreCommonLib.dsc b/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreCommonLib.dsc index 61d47109..2b207a94 100644 --- a/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreCommonLib.dsc +++ b/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreCommonLib.dsc @@ -136,13 +136,14 @@ VarCheckLib|MdeModulePkg/Library/VarCheckLib/VarCheckLib.inf
PlatformSecureLib|SecurityPkg/Library/PlatformSecureLibNull/PlatformSecureLibNull.inf
AuthVariableLib|MdeModulePkg/Library/AuthVariableLibNull/AuthVariableLibNull.inf
-
+
!if gMinPlatformPkgTokenSpaceGuid.PcdUefiSecureBootEnable == TRUE
AuthVariableLib|SecurityPkg/Library/AuthVariableLib/AuthVariableLib.inf
!endif
SafeIntLib|MdePkg/Library/BaseSafeIntLib/BaseSafeIntLib.inf
BmpSupportLib|MdeModulePkg/Library/BaseBmpSupportLib/BaseBmpSupportLib.inf
+ LargeVariableReadLib|MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableReadLib.inf
#
# CryptLib
diff --git a/Platform/Intel/MinPlatformPkg/Include/Library/LargeVariableReadLib.h b/Platform/Intel/MinPlatformPkg/Include/Library/LargeVariableReadLib.h new file mode 100644 index 00000000..df5020b9 --- /dev/null +++ b/Platform/Intel/MinPlatformPkg/Include/Library/LargeVariableReadLib.h @@ -0,0 +1,61 @@ +/** @file
+ Large Variable Read Lib
+
+ This library is used to retrieve large data sets using the UEFI Variable
+ Services. At time of writing, most UEFI Variable Services implementations do
+ not allow more than 64KB of data to be stored in a single UEFI variable. This
+ library will split data sets across multiple variables as needed.
+
+ In the case where more than one variable is needed to store the data, an
+ integer number will be added to the end of the variable name. This number
+ will be incremented for each variable as needed to retrieve the entire data
+ set.
+
+ The primary use for this library is to create binary compatible drivers
+ and OpROMs which need to work both with TianoCore and other UEFI PI
+ implementations. When customizing and recompiling the platform firmware image
+ is possible, adjusting the value of PcdMaxVariableSize may provide a simpler
+ solution to this problem.
+
+ Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _LARGE_VARIABLE_READ_LIB_H_
+#define _LARGE_VARIABLE_READ_LIB_H_
+
+#include <Uefi/UefiBaseType.h>
+
+/**
+ Returns the value of a large variable.
+
+ @param[in] VariableName A Null-terminated string that is the name of the vendor's
+ variable.
+ @param[in] VendorGuid A unique identifier for the vendor.
+ @param[in, out] DataSize On input, the size in bytes of the return Data buffer.
+ On output the size of data returned in Data.
+ @param[out] Data The buffer to return the contents of the variable. May be NULL
+ with a zero DataSize in order to determine the size buffer needed.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_NOT_FOUND The variable was not found.
+ @retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the result.
+ @retval EFI_INVALID_PARAMETER VariableName is NULL.
+ @retval EFI_INVALID_PARAMETER VendorGuid is NULL.
+ @retval EFI_INVALID_PARAMETER DataSize is NULL.
+ @retval EFI_INVALID_PARAMETER The DataSize is not too small and Data is NULL.
+ @retval EFI_DEVICE_ERROR The variable could not be retrieved due to a hardware error.
+ @retval EFI_SECURITY_VIOLATION The variable could not be retrieved due to an authentication failure.
+
+**/
+EFI_STATUS
+EFIAPI
+GetLargeVariable (
+ IN CHAR16 *VariableName,
+ IN EFI_GUID *VendorGuid,
+ IN OUT UINTN *DataSize,
+ OUT VOID *Data OPTIONAL
+ );
+
+#endif // _LARGE_VARIABLE_READ_LIB_H_
diff --git a/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableReadLib.inf b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableReadLib.inf new file mode 100644 index 00000000..3cd94e00 --- /dev/null +++ b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableReadLib.inf @@ -0,0 +1,51 @@ +## @file
+# Component description file for Large Variable Read Library
+#
+# This library is used to retrieve large data sets using the UEFI Variable
+# Services. At time of writing, most UEFI Variable Services implementations do
+# not allow more than 64KB of data to be stored in a single UEFI variable. This
+# library will split data sets across multiple variables as needed.
+#
+# In the case where more than one variable is needed to store the data, an
+# integer number will be added to the end of the variable name. This number
+# will be incremented for each variable as needed to retrieve the entire data
+# set.
+#
+# The primary use for this library is to create binary compatible drivers
+# and OpROMs which need to work both with TianoCore and other UEFI PI
+# implementations. When customizing and recompiling the platform firmware image
+# is possible, adjusting the value of PcdMaxVariableSize may provide a simpler
+# solution to this problem.
+#
+# Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = BaseLargeVariableReadLib
+ FILE_GUID = 4E9D7D31-A7A0-4004-AE93-D12F1AB08730
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = LargeVariableReadLib
+
+#
+# VALID_ARCHITECTURES = IA32 X64 EBC
+#
+
+[Sources]
+ LargeVariableReadLib.c
+ LargeVariableCommon.h
+
+[Packages]
+ MdePkg/MdePkg.dec
+ MinPlatformPkg/MinPlatformPkg.dec
+
+[LibraryClasses]
+ BaseLib
+ BaseMemoryLib
+ DebugLib
+ PrintLib
+ VariableReadLib
diff --git a/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableCommon.h b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableCommon.h new file mode 100644 index 00000000..b6554764 --- /dev/null +++ b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableCommon.h @@ -0,0 +1,47 @@ +/** @file
+ Large Variable Lib Common Header
+
+ These libraries is used to store large data sets using the UEFI Variable
+ Services. At time of writing, most UEFI Variable Services implementations do
+ not allow more than 64KB of data to be stored in a single UEFI variable. This
+ library will split data sets across multiple variables as needed.
+
+ In the case where more than one variable is needed to store the data, an
+ integer number will be added to the end of the variable name. This number
+ will be incremented for each variable as needed to retrieve the entire data
+ set.
+
+ Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _LARGE_VARIABLE_COMMON_H_
+#define _LARGE_VARIABLE_COMMON_H_
+
+//
+// 1024 was choosen because this is the size of the SMM communication buffer
+// used by VariableDxeSmm to transfer the VariableName from DXE to SMM. Choosing
+// the same size will prevent this library from limiting variable names any
+// more than the MdeModulePkg implementation of UEFI Variable Services does.
+//
+#define MAX_VARIABLE_NAME_SIZE 1024
+
+//
+// The 2012 Windows Hardware Requirements specified a minimum variable size of
+// 32KB. By setting the maximum allowed number of variables to 0x20000, this
+// allows up to 4GB of data to be stored on most UEFI implementations in
+// existence. Older UEFI implementations were known to only provide 8KB per
+// variable. In this case, up to 1GB can be stored. Since 1GB vastly exceeds the
+// size of any known NvStorage FV, choosing this number should effectively
+// enable all available NvStorage space to be used to store the given data.
+//
+#define MAX_VARIABLE_SPLIT 131072 // 0x20000
+
+//
+// There are 6 digits in the number 131072, which means the length of the string
+// representation of this number will be at most 6 characters long.
+//
+#define MAX_VARIABLE_SPLIT_DIGITS 6
+
+#endif // _LARGE_VARIABLE_COMMON_H_
diff --git a/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableReadLib.c b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableReadLib.c new file mode 100644 index 00000000..08690d1f --- /dev/null +++ b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableReadLib.c @@ -0,0 +1,176 @@ +/** @file
+ Large Variable Read Lib
+
+ This library is used to retrieve large data sets using the UEFI Variable
+ Services. At time of writing, most UEFI Variable Services implementations do
+ not allow more than 64KB of data to be stored in a single UEFI variable. This
+ library will split data sets across multiple variables as needed.
+
+ In the case where more than one variable is needed to store the data, an
+ integer number will be added to the end of the variable name. This number
+ will be incremented for each variable as needed to retrieve the entire data
+ set.
+
+ Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PrintLib.h>
+#include <Library/VariableReadLib.h>
+
+#include "LargeVariableCommon.h"
+
+/**
+ Returns the value of a large variable.
+
+ @param[in] VariableName A Null-terminated string that is the name of the vendor's
+ variable.
+ @param[in] VendorGuid A unique identifier for the vendor.
+ @param[in, out] DataSize On input, the size in bytes of the return Data buffer.
+ On output the size of data returned in Data.
+ @param[out] Data The buffer to return the contents of the variable. May be NULL
+ with a zero DataSize in order to determine the size buffer needed.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_NOT_FOUND The variable was not found.
+ @retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the result.
+ @retval EFI_INVALID_PARAMETER VariableName is NULL.
+ @retval EFI_INVALID_PARAMETER VendorGuid is NULL.
+ @retval EFI_INVALID_PARAMETER DataSize is NULL.
+ @retval EFI_INVALID_PARAMETER The DataSize is not too small and Data is NULL.
+ @retval EFI_DEVICE_ERROR The variable could not be retrieved due to a hardware error.
+ @retval EFI_SECURITY_VIOLATION The variable could not be retrieved due to an authentication failure.
+
+**/
+EFI_STATUS
+EFIAPI
+GetLargeVariable (
+ IN CHAR16 *VariableName,
+ IN EFI_GUID *VendorGuid,
+ IN OUT UINTN *DataSize,
+ OUT VOID *Data OPTIONAL
+ )
+{
+ CHAR16 TempVariableName[MAX_VARIABLE_NAME_SIZE];
+ EFI_STATUS Status;
+ UINTN TotalSize;
+ UINTN VarDataSize;
+ UINTN Index;
+ UINTN VariableSize;
+ UINTN BytesRemaining;
+ UINT8 *OffsetPtr;
+
+ VarDataSize = 0;
+
+ //
+ // First check if a variable with the given name exists
+ //
+ Status = VarLibGetVariable (VariableName, VendorGuid, NULL, &VarDataSize, NULL);
+ if (Status == EFI_BUFFER_TOO_SMALL) {
+ if (*DataSize >= VarDataSize) {
+ if (Data == NULL) {
+ Status = EFI_INVALID_PARAMETER;
+ goto Done;
+ }
+ DEBUG ((DEBUG_VERBOSE, "GetLargeVariable: Single Variable Found\n"));
+ Status = VarLibGetVariable (VariableName, VendorGuid, NULL, DataSize, Data);
+ goto Done;
+ } else {
+ *DataSize = VarDataSize;
+ Status = EFI_BUFFER_TOO_SMALL;
+ goto Done;
+ }
+
+ } else if (Status == EFI_NOT_FOUND) {
+ //
+ // Check if the first variable of a multi-variable set exists
+ //
+ if (StrLen (VariableName) >= (MAX_VARIABLE_NAME_SIZE - MAX_VARIABLE_SPLIT_DIGITS)) {
+ DEBUG ((DEBUG_ERROR, "GetLargeVariable: Variable name too long\n"));
+ Status = EFI_OUT_OF_RESOURCES;
+ goto Done;
+ }
+
+ VarDataSize = 0;
+ Index = 0;
+ ZeroMem (TempVariableName, MAX_VARIABLE_NAME_SIZE);
+ UnicodeSPrint (TempVariableName, MAX_VARIABLE_NAME_SIZE, L"%s%d", VariableName, Index);
+ Status = VarLibGetVariable (TempVariableName, VendorGuid, NULL, &VarDataSize, NULL);
+
+ if (Status == EFI_BUFFER_TOO_SMALL) {
+ //
+ // The first variable exists. Calculate the total size of all the variables.
+ //
+ DEBUG ((DEBUG_VERBOSE, "GetLargeVariable: Multiple Variables Found\n"));
+ TotalSize = 0;
+ for (Index = 0; Index < MAX_VARIABLE_SPLIT; Index++) {
+ VarDataSize = 0;
+ ZeroMem (TempVariableName, MAX_VARIABLE_NAME_SIZE);
+ UnicodeSPrint (TempVariableName, MAX_VARIABLE_NAME_SIZE, L"%s%d", VariableName, Index);
+ Status = VarLibGetVariable (TempVariableName, VendorGuid, NULL, &VarDataSize, NULL);
+ if (Status != EFI_BUFFER_TOO_SMALL) {
+ break;
+ }
+ TotalSize += VarDataSize;
+ }
+ DEBUG ((DEBUG_VERBOSE, "TotalSize = %d, NumVariables = %d\n", TotalSize, Index));
+
+ //
+ // Check if the user provided a large enough buffer
+ //
+ if (*DataSize >= TotalSize) {
+ if (Data == NULL) {
+ Status = EFI_INVALID_PARAMETER;
+ goto Done;
+ }
+
+ //
+ // Read the data from all variables
+ //
+ OffsetPtr = (UINT8 *) Data;
+ BytesRemaining = *DataSize;
+ for (Index = 0; Index < MAX_VARIABLE_SPLIT; Index++) {
+ VarDataSize = 0;
+ ZeroMem (TempVariableName, MAX_VARIABLE_NAME_SIZE);
+ UnicodeSPrint (TempVariableName, MAX_VARIABLE_NAME_SIZE, L"%s%d", VariableName, Index);
+ VariableSize = BytesRemaining;
+ DEBUG ((DEBUG_INFO, "Reading %s, Guid = %g,", TempVariableName, VendorGuid));
+ Status = VarLibGetVariable (TempVariableName, VendorGuid, NULL, &VariableSize, (VOID *) OffsetPtr);
+ DEBUG ((DEBUG_INFO, " Size %d\n", VariableSize));
+ if (EFI_ERROR (Status)) {
+ if (Status == EFI_NOT_FOUND) {
+ DEBUG ((DEBUG_VERBOSE, "No more variables found\n"));
+ Status = EFI_SUCCESS; // The end has been reached
+ }
+ goto Done;
+ }
+
+ if (VariableSize < BytesRemaining) {
+ BytesRemaining -= VariableSize;
+ OffsetPtr += VariableSize;
+ } else {
+ DEBUG ((DEBUG_VERBOSE, "All data has been read\n"));
+ BytesRemaining = 0;
+ break;
+ }
+ } //End of for loop
+
+ goto Done;
+ } else {
+ *DataSize = TotalSize;
+ Status = EFI_BUFFER_TOO_SMALL;
+ goto Done;
+ }
+ } else {
+ Status = EFI_NOT_FOUND;
+ }
+ }
+
+Done:
+ DEBUG ((DEBUG_ERROR, "GetLargeVariable: Status = %r\n", Status));
+ return Status;
+}
diff --git a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec index 0811b479..91970a62 100644 --- a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec +++ b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec @@ -85,6 +85,7 @@ VariableReadLib|Include/Library/VariableReadLib.h
VariableWriteLib|Include/Library/VariableWriteLib.h
+ LargeVariableReadLib|Include/Library/LargeVariableReadLib.h
[PcdsFixedAtBuild, PcdsPatchableInModule]
|