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[CHERRY-PICK] Feature/ShadowMicrocode: Comsume FIT Table From HOB #438

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Merged
Michael Kubacki (makubacki) merged 1 commit into from
Sep 1, 2026
+22 −25
Merged

[CHERRY-PICK] Feature/ShadowMicrocode: Comsume FIT Table From HOB #438

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46 changes: 21 additions & 25 deletions IntelSiliconPkg/Feature/ShadowMicrocode/ShadowMicrocodePei.c
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
#include <Register/Intel/Microcode.h>
#include <Register/Intel/Cpuid.h>
#include <Guid/MicrocodeShadowInfoHob.h>
#include <Guid/FitEntryHob.h>
//
// Data structure for microcode patch information
//
Expand Down Expand Up @@ -168,36 +169,29 @@ ShadowMicrocodePatchWorker (
}

/**
Check if FIT table content is valid according to FIT BIOS specification.
Check if cached FIT table content is valid according to FIT BIOS specification.

**/
BOOLEAN
IsValidFitTable (
IN UINT64 FitPointer
IsValidFitEntryHob (
IN FIT_ENTRY_HOB_DATA *FitHobData
)
{
UINT64 FitEnding;
FIRMWARE_INTERFACE_TABLE_ENTRY *FitEntry;
UINT32 EntryNum;
UINT32 Type0Count;
UINT32 Index;

//
// The entire FIT table must reside with in the firmware address range
// of (4GB-16MB) to (4GB-40h).
//
if ((FitPointer < (SIZE_4GB - SIZE_16MB)) || (FitPointer >= (SIZE_4GB - 0x40))) {
//
// Invalid FIT address, treat it as no FIT table.
//
DEBUG ((DEBUG_ERROR, "Error: Invalid FIT pointer 0x%p.\n", FitPointer));
if ((FitHobData == NULL) || (FitHobData->EntryCount == 0)) {
DEBUG ((DEBUG_ERROR, "Error: FIT HOB is empty.\n"));
return FALSE;
}

FitEntry = FitHobData->Entry;

//
// Check FIT header.
//
FitEntry = (FIRMWARE_INTERFACE_TABLE_ENTRY *)(UINTN)FitPointer;
if ((FitEntry[0].Type != FIT_TYPE_00_HEADER) ||
(FitEntry[0].Address != FIT_TYPE_00_SIGNATURE))
{
Expand All @@ -214,14 +208,9 @@ IsValidFitTable (
}

//
// Check FIT ending address in valid range.
// Check cached FIT entry count against the FIT header.
//
EntryNum = *(UINT32 *)(&FitEntry[0].Size[0]) & 0xFFFFFF;
FitEnding = FitPointer + sizeof (FIRMWARE_INTERFACE_TABLE_ENTRY) * EntryNum;
if (FitEnding > (SIZE_4GB - 0x40)) {
DEBUG ((DEBUG_ERROR, "Error: FIT table exceeds valid range.\n"));
return FALSE;
}
EntryNum = *(UINT32 *)(&FitEntry[0].Size[0]) & 0xFFFFFF;

//
// Calculate FIT checksum if Checksum Valid bit is set.
Expand Down Expand Up @@ -286,7 +275,8 @@ ShadowMicrocode (
)
{
EFI_STATUS Status;
UINT64 FitPointer;
VOID *Hob;
FIT_ENTRY_HOB_DATA *FitHobData;
FIRMWARE_INTERFACE_TABLE_ENTRY *FitEntry;
UINT32 EntryNum;
UINT32 Index;
Expand All @@ -305,15 +295,21 @@ ShadowMicrocode (
return EFI_INVALID_PARAMETER;
}

FitPointer = *(UINT64 *)(UINTN)FIT_POINTER_ADDRESS;
if (!IsValidFitTable (FitPointer)) {
Hob = GetFirstGuidHob (&gFitEntryHobGuid);
if (Hob == NULL) {
DEBUG ((DEBUG_ERROR, "%a: FIT Entry HOB not found.\n", __func__));
return EFI_NOT_FOUND;
}

FitHobData = (FIT_ENTRY_HOB_DATA *)GET_GUID_HOB_DATA (Hob);
if (!IsValidFitEntryHob (FitHobData)) {
return EFI_NOT_FOUND;
}

//
// Calculate microcode entry number
//
FitEntry = (FIRMWARE_INTERFACE_TABLE_ENTRY *)(UINTN)FitPointer;
FitEntry = FitHobData->Entry;
EntryNum = *(UINT32 *)(&FitEntry[0].Size[0]) & 0xFFFFFF;
MaxPatchNumber = 0;
for (Index = 0; Index < EntryNum; Index++) {
Expand Down
1 change: 1 addition & 0 deletions IntelSiliconPkg/Feature/ShadowMicrocode/ShadowMicrocodePei.inf
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Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,7 @@
[Guids]
gEdkiiMicrocodeShadowInfoHobGuid
gEdkiiMicrocodeStorageTypeFlashGuid
gFitEntryHobGuid

[Pcd]
gIntelSiliconPkgTokenSpaceGuid.PcdShadowAllMicrocode
Expand Down
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