AmiTcgNvflagSample

Function Table

Address	Name	Description
	ReadUnaligned64
	IoRead32
	CpuPause
	ReadTimeStampCounter
	EnableInterrupts
	DisableInterrupts
	GetCallerEflags
	MmioWrite16
	DebugPrintErrorLevel
	AssertBreakpoint
	MatchHobGuid
	UefiBootServicesTableLibConstructor
	TpmNvFlagWriteVariable
	GetPersistentTpmFlags
	SetPersistentTpmFlags
	TpmNvFlagStub
	AmiTcgNvflagSampleDriver
	ModuleEntryPoint
Module	Global Data
EFI_HANDLE	gImageHandle = NULL;
qword_15B0	*VOID mHobList = NULL; // qword_15A8**
qword_15B8	UINT64 gDebugLevel = 0; // qword_15A0
TCG	Protocol GUID
EFI_GUID	gEfiTcgProtocolGuid = { 0xF67D28B8, 0x1E78, 0x4C19, { 0xB8, 0x7B, 0x1A, 0x99, 0xC2, 0x40, 0x6A, 0x54 } };
TCG	Configuration Protocol GUID
EFI_GUID	gEfiTcgConfigProtocolGuid = { 0xD7F12B7E, 0x64B7, 0x4B0B, { 0x99, 0xBF, 0xCB, 0x7B, 0xFA, 0x8F, 0x1D, 0x8C } };
Variable	GUIDs
EFI_GUID	gTcgInterfaceVarGuid = { 0x94B0F9D0, 0x8B8A, 0x4F63, { 0x87, 0x0E, 0x35, 0x5D, 0xFE, 0x42, 0x26, 0x55 } }; // unk_1510
unk_14F0	EFI_GUID gTcgNvDataGuid = { 0xAB954E08, 0x6F10, 0x4C29, { 0xB5, 0xA5, 0xE8, 0x3E, 0x60, 0x5D, 0x71, 0x23 } }; // unk_14E0
PCD	Token Space GUID
EFI_GUID	gPcdTokenSpaceGuid = { 0x9B3ADA11, 0x5CBC, 0x4C41, { 0xA8, 0x1F, 0x0E, 0xAD, 0x64, 0x7B, 0xBE, 0x6C } };
HOB	GUID for locating HOB list in configuration table
EFI_GUID	gHobGuid = { 0x7739F24C, 0x93D7, 0x11D4, { 0x9A, 0x3A, 0x00, 0x90, 0x27, 0x3F, 0xC1, 0x4D } }; // unk_1520/unk_1528
EFI	Driver Binding Protocol instance
unk_1500	- The driver binding protocol instance
EFI_DRIVER_BINDING_PROTOCOL	mDriverBinding = {
Supported	NULL, // Stop
Version	NULL, // ImageHandle
DriverBindingHandle	};
Forward	declarations for protocol function table
off_1550	- Function table for protocol interface
off_1560	- Alternative function table for protocol interface
EFI_OPEN_PROTOCOL_INFORMATION_ENTRY	mProtocolFuncTable[2];
Check	error level filtering
Read	CMOS index 0x4B to determine debug level
IoWrite8	**(0x70, (IoRead8 (0x70) & 0x80)	0x4B);**
Save	ImageHandle and SystemTable
gImageHandle	= ImageHandle;
Initialize	HOB list
GetHobList	();
Initialize	PCI Express base address from PCD
mPciExpressBaseAddress	*= ((UINT64 ()(UINTN))GetPcdProtocol ()->GetPcdValue (PcdPciExpressBaseAddress))(5);**
Enable	PCI Express MMIO access
if	*((INT8)((UINT8* )PciExpressLibGetPciExpressAddress (PCI_EXPRESS_LIB_ADDRESS (0, 0, 0, 0))) >= 0) {**
Delay	calibration: use RDTSC to calibrate a ~1ms delay
Eflags	= GetCallerEflags ();
while	((((CurrentTsc + 357 - (UINTN)IoRead32 (TIMER_PORT)) & 0x800000) == 0)) {
Query	the variable; create it if it doesn't exist
Status	= gRT->QueryVariableInfo (VariableName, VendorGuid, 0, 0, 0);
Variable	doesn't exist; attempt to create it
Status	= gRT->SetVariable (VariableName, VendorGuid, Attributes, DataSize, Data);
Now	write to the variable with the same data
Variable	doesn't exist; create and write
Locate	TCG protocol
Status	= gBS->LocateProtocol (&gEfiTcgProtocolGuid, NULL, &TcgProtocol);
Read	TcgInterfaceVar to check interface state
BufferSize	= sizeof (TcgInterface);
Read	INTERNALPERBIOSFLAGS
InternalFlagsSize	= sizeof (InternalFlags);
Internal	flags not found; set defaults
Set	bit 4 in flags
Copy	internal flags to output buffer
CopyMem	(Flags, InternalFlags, 6);
Locate	TCG protocols
Status	= gBS->LocateProtocol (&gEfiTcgProtocolGuid, NULL, (VOID )&TcgProtocol);**
Read	TcgInterfaceVar to check if TCG interface is active
TCG	interface is active; write flags to INTERNALPERBIOSFLAGS
CopyMem	(InternalFlags, Flags, sizeof (InternalFlags));
TcgInterface	**	= 1;**
Write	INTERNALPERBIOSFLAGS again with actual flags
Status	= TpmNvFlagWriteVariable (
Locate	TCG Config protocol
Status	= gBS->LocateProtocol (&gEfiTcgConfigProtocolGuid, NULL, (VOID )&TcgConfigProtocol);**
Check	TPM NV registers at physical address 0xFED40F00 for
contains	3 entries (12 bytes total, 4 bytes per entry).
for	(Index = 0; Index < 0xC; Index += 4) {
Compare	against known manufacturer flag table
if	*((UINT16* )((UINT8 )&ManufacturerCheckValue + Index) == TpmManufacturerId &&*
Manufacturer	match found; register driver binding
return	gBS->InstallMultipleProtocolInterfaces (
No	manufacturer match; try reading existing flags
ZeroMem	(DefaultFlags, sizeof (DefaultFlags));
Failed	to read flags; set defaults
Version	1, flags byte 0 = 1
Register	the driver binding protocol
Initialize	UEFI boot/runtime services and hardware abstraction
UefiBootServicesTableLibConstructor	(ImageHandle, SystemTable);
Execute	the main TCG NV flag sample logic
return	AmiTcgNvflagSampleDriver (ImageHandle, SystemTable);

Generated by HR650X BIOS Decompilation Project