CpuIo2Smm

Function Table

Address	Name	Description
	SmmSetJump
	SmmLongJump
	CpuIo2SmmValidateJumpBuffer
	CpuIo2SmmInitServices
	CpuIo2SmmCheckParameter
	CpuIo2SmmMemRead
	CpuIo2SmmMemWrite
	CpuIo2SmmIoRead
	CpuIo2SmmIoWrite
	CpuIo2SmmInstallProtocol
	CpuIo2SmmDebugVPrint
	CpuIo2SmmDebugAssert
	CpuIo2SmmDriverEntryPoint
Stride	per width index: mSmmIoStride[Width] = { 1, 2, 4, 8 }
Stored	at 0xE18.
CONST	UINT8 mSmmIoStride[] = { 1, 2, 4, 8 };
Globals	initialized by CpuIo2SmmInitServices
EFI_HANDLE	gImageHandle = NULL; // 0x13E8
0x13D8	*EFI_BOOT_SERVICES gBS = NULL; // 0x13E0**
0x13F0	*VOID gSmst = NULL; // 0x13F8 (SMM System Table 2)**
0x1400	(DebugLib protocol)
SetJump	buffer for SmmBase2->GetSmstLocation communication
Stored	at 0x1410.
BASE_LIBRARY_JUMP_BUFFER	gJumpBuffer;
EFI_SMM_CPU_IO2_PROTOCOL	function table template at 0x13B0.
32	bytes: 4 x 8-byte function pointers:
EFI_SMM_CPU_IO2_PROTOCOL	gCpuIoTemplate = {
Mem	CpuIo2SmmMemRead, // .Read
Io	CpuIo2SmmIoRead, // .Read
Protocol	handle (initialized to NULL before installation)
Stored	at 0x13D0.
EFI_HANDLE	mCpuIo2Handle = NULL;
Module	status - starts as EFI_UNSUPPORTED (0x8000000000000001)
Stored	at 0x1508. Updated with result from protocol installation.
EFI_STATUS	gStatus = EFI_UNSUPPORTED;
Internal	Helpers (library bindings)
InternalCopyMem	(0x2C0) - aligned copy with overlap handling
STATIC	VOID *
SmmSetJump	(0x310) - save execution context
STATIC	UINTN
SmmLongJump	(0x3B0) - restore execution context
STATIC	VOID
CpuIo2SmmValidateJumpBuffer	(0xCE8)
Validates	alignment of JumpBuffer for SetJump.
CpuIo2SmmInitServices	(0x524)
AutoGen	function that initializes gBS, gRT, gSmst from SystemTable.
Called	once during module entry.
Also	locates EFI_SMM_BASE2_PROTOCOL (F4CCBFB7-F6E0-47FD-9DD4-10A8F150C191)
and	retrieves the SMM System Table 2 via GetSmstLocation.
Locate	EFI_SMM_BASE2_PROTOCOL
SmmBase2	= NULL;
Retrieve	gSmst via SmmBase2->GetSmstLocation()
Uses	SetJump/LongJump for context switching inside SMM
CpuIo2SmmValidateJumpBuffer	(&gJumpBuffer);
CpuIo2SmmCheckParameter	(0x664)
Validates	I/O parameters for all four protocol interface functions.
EFI_SUCCESS	- parameters are valid
EFI_INVALID_PARAMETER	- invalid width, alignment, or out of range
Basic	validation: Buffer must not be NULL, Width must be valid
and	QWord I/O (Width=3) is not supported for port I/O.
if	**((Buffer == NULL)		(Width > SmmIoWidthUint64)	**
Maximum	address:
if	(MmioOperation) {
If	Count > 0, ensure the access range does not exceed MaxAddress.
Stride	is mSmmIoStride[Width]: 1, 2, 4, or 8 bytes.
if	(Count > 0) {
Check	start address is within bounds
if	(Address > MaxAddress) {
if	((Address & (mSmmIoStride[Width] - 1)) != 0) {
EFI_SMM_CPU_IO2_PROTOCOL	Interface Functions
CpuIo2SmmMemRead	(0x76C)
MMIO	read via direct memory pointer dereference.
Reads	Count elements of Width from Address into Buffer.
EFI_STATUS	EFIAPI
CpuIo2SmmMemWrite	(0x850)
MMIO	write via direct memory pointer dereference.
Writes	Count elements of Width from Buffer into Address.
CpuIo2SmmIoRead	(0x934)
Reads	Count elements of Width from I/O Port Address into Buffer.
QWord	I/O port access is not supported by x86 ISA
CpuIo2SmmIoWrite	(0xA10)
Writes	Count elements of Width from Buffer to I/O Port Address.
CpuIo2SmmInstallProtocol	(0xAF0)
Installs	EFI_SMM_CPU_IO2_PROTOCOL via gSmst->SmmInstallProtocolInterface.
Also	copies the function table to SmmIoMemAbstraction area of Smst.
Copy	protocol function table to Smst+0x30
CopyMem	(
Install	protocol into SMM protocol database
Status	= Smst->SmmInstallProtocolInterface (
Debug	Protocol Support
The	GUID at 0x1390 (441FFA18-8714-421E-8C95-587080796FEE) is used to
locate	a debug print protocol via gSmst->SmmLocateProtocol.
CpuIo2SmmGetDebugProtocol	(0xBD0)
CpuIo2SmmDebugVPrint	(0xC20)
Debug	print using the located debug protocol.
Read	debug level from CMOS register 0x4C
CmosIndex	**= IoRead8 (0x70) & 0x80	0x4C;**
Determine	debug print level from CMOS byte
DebugLevel	= 0;
CpuIo2SmmDebugAssert	(0xCA8)
Debug	assert call. Invokes the debug protocol's assert handler.
_ModuleEntryPoint	(0x484)
Phase	1: Initialize global service table pointers
Status	= CpuIo2SmmInitServices (ImageHandle, SystemTable);
Phase	2: Install EFI_SMM_CPU_IO2_PROTOCOL
if	(!EFI_ERROR (Status)) {
The	jump buffer at gJumpBuffer (0x1410) is used by AutoGen.
Preserve	install error if init was OK but install failed
gStatus	= Status;

Generated by HR650X BIOS Decompilation Project