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refine VariablePei driver to unify the algorithm of access VariableIndexTable among various archs.

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1. record the distance of two neighboring VAR_ADDED type variables rather than the offset of each variable. As the field recording this info is UINT16 width, the latter causes in IA32/X64 platform, it can only cache those variables from offset 0 to offset 2^16; in IPF platform, from offset 0 to offset 2^18(extend the scope by left-shift the offset two bits).
when taking the former algorithm, the max range of caching variable is from offset 0 to offset 122*(2^16)

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8625 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
eric_tian
2009-06-23 08:30:04 +00:00
parent 48a9ea7b1b
commit 841014ba97
5 changed files with 45 additions and 163 deletions
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44
MdeModulePkg/Universal/Variable/Pei/Variable.c
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@@ -366,10 +366,13 @@ FindVariable (
EFI_HOB_GUID_TYPE *GuidHob;
VARIABLE_STORE_HEADER *VariableStoreHeader;
VARIABLE_HEADER *Variable;
VARIABLE_HEADER *LastVariable;
VARIABLE_HEADER *MaxIndex;
VARIABLE_INDEX_TABLE *IndexTable;
UINT32 Count;
UINT32 Offset;
UINT8 *VariableBase;
BOOLEAN StopRecord;
if (VariableName[0] != 0 && VendorGuid == NULL) {
return EFI_INVALID_PARAMETER;
@@ -378,9 +381,16 @@ FindVariable (
// No Variable Address equals zero, so 0 as initial value is safe.
//
MaxIndex = 0;
StopRecord = FALSE;
GuidHob = GetFirstGuidHob (&mEfiVariableIndexTableGuid);
if (GuidHob == NULL) {
//
// If it's the first time to access variable region in flash, create a guid hob to record
// VAR_ADDED type variable info.
// Note that as the resource of PEI phase is limited, only store the number of
// VARIABLE_INDEX_TABLE_VOLUME of VAR_ADDED type variables to reduce access time.
//
IndexTable = BuildGuidHob (&mEfiVariableIndexTableGuid, sizeof (VARIABLE_INDEX_TABLE));
IndexTable->Length = 0;
IndexTable->StartPtr = NULL;
@@ -388,9 +398,13 @@ FindVariable (
IndexTable->GoneThrough = 0;
} else {
IndexTable = GET_GUID_HOB_DATA (GuidHob);
for (Count = 0; Count < IndexTable->Length; Count++) {
MaxIndex = GetVariableByIndex (IndexTable, Count);
for (Offset = 0, Count = 0; Count < IndexTable->Length; Count++) {
//
// traverse the variable info list to look for varible.
// The IndexTable->Index[Count] records the distance of two neighbouring VAR_ADDED type variables.
//
Offset += IndexTable->Index[Count];
MaxIndex = (VARIABLE_HEADER *)((CHAR8 *)(IndexTable->StartPtr) + Offset);
if (CompareWithValidVariable (MaxIndex, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
PtrTrack->StartPtr = IndexTable->StartPtr;
PtrTrack->EndPtr = IndexTable->EndPtr;
@@ -407,7 +421,8 @@ FindVariable (
// If not found in HOB, then let's start from the MaxIndex we've found.
//
if (MaxIndex != NULL) {
Variable = GetNextVariablePtr (MaxIndex);
Variable = GetNextVariablePtr (MaxIndex);
LastVariable = MaxIndex;
} else {
if ((IndexTable->StartPtr != NULL) || (IndexTable->EndPtr != NULL)) {
Variable = IndexTable->StartPtr;
@@ -435,6 +450,8 @@ FindVariable (
//
Variable = IndexTable->StartPtr;
}
LastVariable = IndexTable->StartPtr;
}
//
// Find the variable by walk through non-volatile variable store
@@ -447,8 +464,23 @@ FindVariable (
//
// Record Variable in VariableIndex HOB
//
VariableIndexTableUpdate (IndexTable, Variable);
if (IndexTable->Length < VARIABLE_INDEX_TABLE_VOLUME && StopRecord != TRUE) {
Offset = (UINT32)((UINTN)Variable - (UINTN)LastVariable);
//
// The distance of two neighbouring VAR_ADDED variable is larger than 2^16,
// which is beyond the allowable scope(UINT16) of record. In such case, need not to
// record the subsequent VAR_ADDED type variables again.
//
if ((Offset & 0xFFFF0000UL) != 0) {
StopRecord = TRUE;
}
if (StopRecord != TRUE) {
IndexTable->Index[IndexTable->Length++] = (UINT16) Offset;
}
LastVariable = Variable;
}
if (CompareWithValidVariable (Variable, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
return EFI_SUCCESS;
}