diff options
Diffstat (limited to 'OvmfPkg')
| -rw-r--r-- | OvmfPkg/PlatformDxe/Platform.inf | 11 | ||||
| -rw-r--r-- | OvmfPkg/PlatformDxe/PlatformConfig.c | 131 | ||||
| -rw-r--r-- | OvmfPkg/PlatformDxe/PlatformConfig.h | 59 |
3 files changed, 200 insertions, 1 deletions
diff --git a/OvmfPkg/PlatformDxe/Platform.inf b/OvmfPkg/PlatformDxe/Platform.inf index 42a104c5b5..47ed25b5c7 100644 --- a/OvmfPkg/PlatformDxe/Platform.inf +++ b/OvmfPkg/PlatformDxe/Platform.inf @@ -26,6 +26,7 @@ [Sources]
Platform.c
+ PlatformConfig.c
[Packages]
MdePkg/MdePkg.dec
@@ -33,9 +34,17 @@ OvmfPkg/OvmfPkg.dec
[LibraryClasses]
+ BaseMemoryLib
DebugLib
+ MemoryAllocationLib
UefiBootServicesTableLib
+ UefiLib
+ UefiRuntimeServicesTableLib
UefiDriverEntryPoint
+[Guids]
+ gOvmfPlatformConfigGuid
+
[Depex]
- TRUE
+ gEfiVariableArchProtocolGuid AND
+ gEfiVariableWriteArchProtocolGuid
diff --git a/OvmfPkg/PlatformDxe/PlatformConfig.c b/OvmfPkg/PlatformDxe/PlatformConfig.c new file mode 100644 index 0000000000..3468f88150 --- /dev/null +++ b/OvmfPkg/PlatformDxe/PlatformConfig.c @@ -0,0 +1,131 @@ +/** @file
+
+ Utility functions for serializing (persistently storing) and deserializing
+ OVMF's platform configuration.
+
+ Copyright (C) 2014, Red Hat, Inc.
+
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License which accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+ WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+#include <Guid/OvmfPlatformConfig.h>
+
+#include "PlatformConfig.h"
+
+//
+// Name of the UEFI variable that we use for persistent storage.
+//
+STATIC CHAR16 mVariableName[] = L"PlatformConfig";
+
+
+/**
+ Serialize and persistently save platform configuration.
+
+ @param[in] PlatformConfig The platform configuration to serialize and save.
+
+ @return Status codes returned by gRT->SetVariable().
+**/
+EFI_STATUS
+EFIAPI
+PlatformConfigSave (
+ IN PLATFORM_CONFIG *PlatformConfig
+ )
+{
+ EFI_STATUS Status;
+
+ //
+ // We could implement any kind of translation here, as part of serialization.
+ // For example, we could expose the platform configuration in separate
+ // variables with human-readable contents, allowing other tools to access
+ // them more easily. For now, just save a binary dump.
+ //
+ Status = gRT->SetVariable (mVariableName, &gOvmfPlatformConfigGuid,
+ EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ sizeof *PlatformConfig, PlatformConfig);
+ return Status;
+}
+
+
+/**
+ Load and deserialize platform configuration.
+
+ When the function fails, output parameters are indeterminate.
+
+ @param[out] PlatformConfig The platform configuration to receive the
+ loaded data.
+
+ @param[out] OptionalElements This bitmap describes the presence of optional
+ configuration elements that have been loaded.
+ PLATFORM_CONFIG_F_DOWNGRADE means that some
+ unknown elements, present in the wire format,
+ have been ignored.
+
+ @retval EFI_SUCCESS Loading & deserialization successful.
+ @return Error codes returned by GetVariable2().
+**/
+EFI_STATUS
+EFIAPI
+PlatformConfigLoad (
+ OUT PLATFORM_CONFIG *PlatformConfig,
+ OUT UINT64 *OptionalElements
+ )
+{
+ VOID *Data;
+ UINTN DataSize;
+ EFI_STATUS Status;
+
+ //
+ // Any translation done in PlatformConfigSave() would have to be mirrored
+ // here. For now, just load the binary dump.
+ //
+ // Versioning of the binary wire format is implemented based on size
+ // (only incremental changes, ie. new fields), and on GUID.
+ // (Incompatible changes require a GUID change.)
+ //
+ Status = GetVariable2 (mVariableName, &gOvmfPlatformConfigGuid, &Data,
+ &DataSize);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ *OptionalElements = 0;
+ if (DataSize > sizeof *PlatformConfig) {
+ //
+ // Handle firmware downgrade -- keep only leading part.
+ //
+ CopyMem (PlatformConfig, Data, sizeof *PlatformConfig);
+ *OptionalElements |= PLATFORM_CONFIG_F_DOWNGRADE;
+ } else {
+ CopyMem (PlatformConfig, Data, DataSize);
+
+ //
+ // Handle firmware upgrade -- zero out missing fields.
+ //
+ ZeroMem ((UINT8 *)PlatformConfig + DataSize,
+ sizeof *PlatformConfig - DataSize);
+ }
+
+ //
+ // Based on DataSize, report the optional features that we recognize.
+ //
+ if (DataSize >= (OFFSET_OF (PLATFORM_CONFIG, VerticalResolution) +
+ sizeof PlatformConfig->VerticalResolution)) {
+ *OptionalElements |= PLATFORM_CONFIG_F_GRAPHICS_RESOLUTION;
+ }
+
+ FreePool (Data);
+ return EFI_SUCCESS;
+}
diff --git a/OvmfPkg/PlatformDxe/PlatformConfig.h b/OvmfPkg/PlatformDxe/PlatformConfig.h new file mode 100644 index 0000000000..3fd6982566 --- /dev/null +++ b/OvmfPkg/PlatformDxe/PlatformConfig.h @@ -0,0 +1,59 @@ +/** @file
+
+ Utility functions for serializing (persistently storing) and deserializing
+ OVMF's platform configuration.
+
+ Copyright (C) 2014, Red Hat, Inc.
+
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License which accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+ WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#ifndef _PLATFORM_CONFIG_H_
+#define _PLATFORM_CONFIG_H_
+
+#include <Base.h>
+
+//
+// This structure participates in driver configuration. It does not
+// (necessarily) reflect the wire format in the persistent store.
+//
+#pragma pack(1)
+typedef struct {
+ //
+ // preferred graphics console resolution when booting
+ //
+ UINT32 HorizontalResolution;
+ UINT32 VerticalResolution;
+} PLATFORM_CONFIG;
+#pragma pack()
+
+//
+// Please see the API documentation near the function definitions.
+//
+EFI_STATUS
+EFIAPI
+PlatformConfigSave (
+ IN PLATFORM_CONFIG *PlatformConfig
+ );
+
+EFI_STATUS
+EFIAPI
+PlatformConfigLoad (
+ OUT PLATFORM_CONFIG *PlatformConfig,
+ OUT UINT64 *OptionalElements
+ );
+
+//
+// Feature flags for OptionalElements.
+//
+#define PLATFORM_CONFIG_F_GRAPHICS_RESOLUTION BIT0
+#define PLATFORM_CONFIG_F_DOWNGRADE BIT63
+
+#endif // _PLATFORM_CONFIG_H_
|