/** @file Variable services implemented from system memory There is just a single runtime memory buffer that contans all the data. Copyright (c) 2007, Intel Corporation
Portions copyright (c) 2008-2009, Apple Inc. All rights reserved. All rights reserved. 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. **/ UINT64 mMaximumVariableStorageSize; UINT64 mRemainingVariableStorageSize; UINT64 mMaximumVariableSize; typedef struct { EFI_GUID VendorGuid; UINT32 Attribute; UINTN DataSize; } VARIABLE_ARRAY_ENTRY; // CHAR16 VariableName[] // UINT8 Data[] VARIABLE_ARRAY_ENTRY *mVariableArray = NULL; VARIABLE_ARRAY_ENTRY *mVariableArrayNextFree = NULL; VARIABLE_ARRAY_ENTRY *mVariableArrayEnd = NULL; VARIABLE_ARRAY_ENTRY * AddEntry ( IN CHAR16 *VariableName, IN EFI_GUID *VendorGuid, IN UINT32 Attributes, IN UINTN DataSize, IN VOID *Data ) { UINTN Size; UINTN SizeOfString; VARIABLE_ARRAY_ENTRY *Entry; EFI_TPL CurrentTpl; SizeOfString = StrSize (VariableName); Size = SizeOfString + sizeof (VARIABLE_ARRAY_ENTRY) + DataSize; if ((VARIABLE_ARRAY_ENTRY *)(((UINT8 *)mVariableArrayNextFree) + Size) > mVariableArrayEnd) { // ran out of space return NULL; } if (!EfiAtRuntime ()) { // Enter critical section CurrentTpl = gBS->RaiseTPL (EFI_TPL_HIGH_LEVEL); } Entry = mVariableArrayNextFree; CopyGuid (&Entry->VendorGuid, VendorGuid); Entry->Attribute = Attributes; Entry->DataSize = DataSize; StrCpy ((CHAR16 *)++mVariableArrayNextFree, VariableName); mVariableArrayNextFree = (VARIABLE_ARRAY_ENTRY *)(((UINT8 *)mVariableArrayNextFree) + SizeOfString); CopyMem (mVariableArrayNextFree, Data, DataSize); mVariableArrayNextFree = (VARIABLE_ARRAY_ENTRY *)(((UINT8 *)mVariableArrayNextFree) + DataSize); if (!EfiAtRuntime ()) { // Exit Critical section gBS->RestoreTPL (CurrentTpl); } return Entry; } VOID DeleteEntry ( IN VARIABLE_ARRAY_ENTRY *Entry ) { UINTN Size; UINT8 *Data; EFI_TPL CurrentTpl; Size = StrSize ((CHAR16 *)(Entry + 1)) + sizeof (VARIABLE_ARRAY_ENTRY) + Entry->DataSize; Data = ((UINT8 *)Entry) + Size; CopyMem (Entry, Data, (UINTN)mVariableArrayNextFree - (UINTN)Data); if (!EfiAtRuntime ()) { // Enter critical section CurrentTpl = gBS->RaiseTPL (EFI_TPL_HIGH_LEVEL); } mVariableArrayNextFree = (VARIABLE_ARRAY_ENTRY *)(((UINT8 *)mVariableArrayNextFree) - Size); if (!EfiAtRuntime ()) { // Exit Critical section gBS->RestoreTPL (CurrentTpl); } } VARIABLE_ARRAY_ENTRY * GetVariableArrayEntry ( IN CHAR16 *VariableName, IN EFI_GUID *VendorGuid, OUT VOID **Data OPTIONAL ) { VARIABLE_ARRAY_ENTRY *Entry; UINTN Size; if (*VariableName == L'\0') { // by definition first entry is null-terminated string if (mVariableArray == mVariableArrayNextFree) { return NULL; } return mVariableArray; } for (Entry = mVariableArray; Entry < mVariableArrayEnd;) { if (CompareGuid (VendorGuid, &Entry->VendorGuid)) { if (StrCmp (VariableName, (CHAR16 *)(Entry + 1))) { Size = StrSize ((CHAR16 *)(Entry + 1)); if (Data != NULL) { *Data = (VOID *)(((UINT8 *)Entry) + (Size + sizeof (VARIABLE_ARRAY_ENTRY))); } return Entry; } } Size = StrSize ((CHAR16 *)(Entry + 1)) + sizeof (VARIABLE_ARRAY_ENTRY) + Entry->DataSize; Entry = (VARIABLE_ARRAY_ENTRY *)(((UINT8 *)Entry) + Size); } return NULL; } EFI_STATUS LibGetVariable ( IN CHAR16 *VariableName, IN EFI_GUID *VendorGuid, OUT UINT32 *Attributes OPTIONAL, IN OUT UINTN *DataSize, OUT VOID *Data ) { VARIABLE_ARRAY_ENTRY *Entry; VOID *InternalData; if (EfiAtRuntime () && (Attributes != NULL)) { if ((*Attributes & EFI_VARIABLE_RUNTIME_ACCESS) == 0) { return EFI_NOT_FOUND; } } Entry = GetVariableArrayEntry (VariableName, VendorGuid, &InternalData); if (Entry == NULL) { return EFI_NOT_FOUND; } if (*DataSize < Entry->DataSize) { *DataSize = Entry->DataSize; return EFI_BUFFER_TOO_SMALL; } *DataSize = Entry->DataSize; if (Attributes != NULL) { *Attributes = Entry->Attribute; } CopyMem (Data, InternalData, *DataSize); return EFI_SUCCESS; } EFI_STATUS LibGetNextVariableName ( IN OUT UINTN *VariableNameSize, IN OUT CHAR16 *VariableName, IN OUT EFI_GUID *VendorGuid ) { VARIABLE_ARRAY_ENTRY *Entry; VOID *InternalData; UINTN StringSize; BOOLEAN Done; for (Done = FALSE; !Done; ) { Entry = GetVariableArrayEntry (VariableName, VendorGuid, &InternalData); if (Entry == NULL) { return EFI_NOT_FOUND; } // If we are at runtime skip variables that do not have the Runitme attribute set. Done = (EfiAtRuntime () && ((Entry->Attribute & EFI_VARIABLE_RUNTIME_ACCESS) == 0)) ? FALSE : TRUE; } StringSize = StrSize ((CHAR16 *)(Entry + 1)); Entry = (VARIABLE_ARRAY_ENTRY *)(((UINT8 *)Entry) + (StringSize + sizeof (VARIABLE_ARRAY_ENTRY) + Entry->DataSize)); if (Entry >= mVariableArrayEnd) { return EFI_NOT_FOUND; } if (*VariableNameSize < StringSize) { *VariableNameSize = StringSize; return EFI_BUFFER_TOO_SMALL; } *VariableNameSize = StringSize; CopyMem (VariableName, (CHAR16 *)(Entry + 1), StringSize); CopyMem (VendorGuid, &Entry->VendorGuid, sizeof (EFI_GUID)); return EFI_SUCCESS; } EFI_STATUS LibSetVariable ( IN CHAR16 *VariableName, IN EFI_GUID *VendorGuid, IN UINT32 Attributes, IN UINTN DataSize, IN VOID *Data ) { VARIABLE_ARRAY_ENTRY *Entry; VOID *InternalData; if (EfiAtRuntime () && ((Attributes & EFI_VARIABLE_RUNTIME_ACCESS) == 0)) { return EFI_NOT_FOUND; } Entry = GetVariableArrayEntry (VariableName, VendorGuid, &InternalData); if (Entry == NULL) { if (DataSize == 0) { return EFI_NOT_FOUND; } Entry = AddEntry (VariableName, VendorGuid, Attributes, DataSize, Data); return (Entry == NULL) ? EFI_OUT_OF_RESOURCES : EFI_SUCCESS; } else if (DataSize == 0) { // DataSize is zero so delete DeleteEntry (Entry); } else if (DataSize == Entry->DataSize) { // No change is size so just update the store Entry->Attribute |= Attributes; CopyMem (InternalData, Data, DataSize); } else { // Grow the entry by deleting and adding back. Don't lose previous Attributes Attributes |= Entry->Attribute; DeleteEntry (Entry); Entry = AddEntry (VariableName, VendorGuid, Attributes, DataSize, Data); return (Entry == NULL) ? EFI_OUT_OF_RESOURCES : EFI_SUCCESS; } } EFI_STATUS LibQueryVariableInfo ( IN UINT32 Attributes, OUT UINT64 *MaximumVariableStorageSize, OUT UINT64 *RemainingVariableStorageSize, OUT UINT64 *MaximumVariableSize ) { *MaximumVariableStorageSize = mMaximumVariableStorageSize; *RemainingVariableStorageSize = mRemainingVariableStorageSize; *MaximumVariableStorageSize = mRemainingVariableStorageSize; return EFI_SUCCESS; } VOID LibVariableVirtualAddressChangeEvent (VOID) { EfiConvertPointer (0, (VOID **)&mVariableArray); EfiConvertPointer (0, (VOID **)&mVariableArrayNextFree); EfiConvertPointer (0, (VOID **)&mVariableArrayEnd); } VOID LibVariableInitialize (VOID) { UINTN Size; Size = PcdGet32 (PcdEmbeddedMemVariableStoreSize); mVariableArray = mVariableArrayNextFree = (VARIABLE_ARRAY_ENTRY *)AllocateRuntimePool (Size); ASSERT (mVariableArray != NULL); mVariableArrayEnd = (VARIABLE_ARRAY_ENTRY *)(((UINT8 *)mVariableArray) + Size); mMaximumVariableStorageSize = Size - sizeof (VARIABLE_ARRAY_ENTRY); mRemainingVariableStorageSize = mMaximumVariableStorageSize; mMaximumVariableSize = mMaximumVariableStorageSize; }