CsmDxe

Function Table

Address	Name	Description
	CsmDxeConstructor
	CsmDxeDriverEntryPoint
	CsmDxeUnload
	_mm_pause_w
	__rdtsc_w
	_enable_w
	_disable_w
	__getcallerseflags_w
	CsmThunk16Entry
	ModuleEntryPoint
	CsmLegacyBiosInstallProtocol
	CsmRegisterBootEventCallbacks
	CsmLocateAmiBoardInfo2
	CsmAllConnectedCallback
	CsmInstallProtocolNotifications
	CsmShadowAllLegacyOproms
	CsmInitializePciPlatform
	CsmInitializeLegacyBios
	CsmLegacyBiosGetBbsInfo
	CsmLegacyBiosSetBdaComPort
	CsmLegacyBiosBoot
	CsmLegacyBiosBootUnconventionalDevice
	CsmLegacyBiosUpdateKeyboardLedStatus
	CsmLegacyBiosPrepareToBootEfi
	CsmLegacyBiosShadowAllLegacyOproms
	CsmLegacyBiosInstall
	CsmLegacyBiosUninstall
	CsmLegacyBiosSetBdaBase
	CsmLegacyBiosGetBbsInfo_GetCount
	CsmSaveBootScriptToLockBox
	CsmDebugPrint
	CsmAssert
	nullsub_1
These	functions are library-internal wrappers linked from:
sub_B638	= DebugPrint (EfiDLevel, Format, ...)
sub_B680	= Assert (FileName, Line, Expression)
sub_B6C0	= LibPcdGetPtr (or LibPcdGetSize)
sub_B74C	= DxeServicesTableLib constructor
sub_B588	= ReadTimeStampCounter (via __rdtsc)
sub_B8FC	= MmPciBaseLib constructor
sub_B980	= PcdGetPtr (by token number)
sub_BA94	= DebugClearMemory / gBS->SetMem
sub_D71C	= MmioWrite32 (or similar)
sub_D7B0	= PcieSegBusTableInit
sub_CA38	= gBS->InstallMultipleProtocolInterfaces
sub_CD38	= DriverBinding / handle protocol uninstalls
sub_CFB4	= gBS->LocateProtocol for AMI_BOARD_INFO2_PROTOCOL
sub_D03C	= gBS->LocateHandleBuffer
Implementation	not shown - thunk to 16-bit code
This	is the "library constructor" pattern. The original source is
The	real work of the driver happens in CsmDxeDriverEntryPoint.
Standard	UEFI BootServicesTableLib constructor
gImageHandle	= (EFI_HANDLE)qword_10BE0;
DxeServicesTableLib	constructor
Status	= DxeServicesTableLibConstructor (&ProtocolGuid, &gDS);
DxeMmPciBaseLib	constructor - initialize PCI USRA protocol
if	(mPciUsra == NULL) {
Initialize	the MMIO PCI Base library
MmPciBaseLibInit	();
Get	PCD value and enable VGA legacy decoding if needed
PcdValue	= LibPcdGetPtr (Token5);
Check	caller EFLAGS for interrupt state (IF bit = bit 9)
Use	__getcallerseflags() intrinsic
CallerFlags	= (UINT16)__getcallerseflags_w ();
TscStart	= __rdtsc_w () & 0xFFFFFF;
Restore	interrupt state
if	(InterruptsEnabled) {
Initialize	PCIe Segment Bus Table
PcieSegBusTableSize	= LibPcdGetSize (Token7);
Register	protocol interfaces via AutoGen
Status	= gBS->InstallMultipleProtocolInterfaces (
Point	to our EFI system table and boot/runtime services
if	(gST == NULL) {
Register	protocol notify for EfiLegacyInterruptProtocol
Check	SecureBoot variable
SecureBootVar	= '\0';
If	SecureBoot is enabled, clear the CSM "Setup" variable
SetupVarSize	= CSM16_CONFIG_SIZE;
Read	the CSM "Setup" variable to determine whether CSM should be enabled
offset	derived from byte_11DA2
Install	the Legacy BIOS protocol interface
Status	= CsmLegacyBiosInstallProtocol (ImageHandle);
Register	boot event callbacks
Status	= CsmRegisterBootEventCallbacks ();
Locate	AMI_BOARD_INFO2_PROTOCOL
if	(mBoardInfo2 == NULL) {
Allocate	the main CSM context (6328 bytes)
Status	= gBS->AllocatePool (
Locate	required protocols for the context
Status	= gBS->LocateProtocol (
Populate	the Legacy BIOS function table
Validate	MaxOpRomAddress (must be 0xC0000-0xF0000)
Status	*= (CsmCtx->PciIoProtocol->AllocateBuffer) (**
Initialize	PCI platform interface
Status	= CsmInitializePciPlatform ();
Get	current video mode
Status	*= (CsmCtx->SmmLegacyBootProtocol->GetCurrentMode) (**
Set	VGA mode to text mode 80x25
DevicePathSize	= (UINT16)-1;
Read	CSM mode from Setup variable
byte_11DA2	offset
Initialize	the Legacy BIOS driver
Status	= CsmInitializeLegacyBios (Csm16Mode, SystemTable);
Set	VGA mode again after CSM16 init
Status	*= (CsmCtx->SmmLegacyBootProtocol->SetMode) (**
Initialize	the PCI enumeration data
Status	*= (CsmCtx->PciIoProtocol->GetLocation) (**
Set	the base OpROM address (0xC0000)
gMaxOpRomAddress	= 0xC0000;
Allocate	PCI data table (1312 bytes)
Offset	for internal data structure
Allocate	BBS table (1728 bytes)
Offset	to BBS data start
Register	event notification for Legacy BIOS protocol
CsmState	= (UINT64)CsmCtx;
Register	notification for AllConnected (via EfiBootScriptNotify)
Status	= gBS->CreateEvent (
Install	protocol notification
Status	= gBS->InstallProtocolInterface (
Install	CSM internal protocol notifications
Register	ShadowAll callback
Status	= gBS->RegisterProtocolNotify (
Set	up callback function pointers
Validate	BoardInfo2 data
ASSERT	*(((AMI_BOARD_INFO2_PROTOCOL )Interface)->DataValid);**
Signal	the "AllConnected" event
return	EFI_SUCCESS;
Shadow	each legacy Option ROM
copies	Option ROM images to 0xC0000-0xF0000 region]
Initialize	PCI device data and Option ROM shadow region
PciData	= NULL;
Additional	PCI platform configuration
return	Status;
Allocate	and initialize the Legacy BIOS interface
Install	Legacy BIOS protocol
Initialize	BBS table
Register	legacy boot event handler
Install	the INT19 trap handler (for legacy boot)
CSM16	entry initialization
Status	= CsmThunk16Entry (Csm16Mode, 0, 0, 0, 0);
derived	from Csm16 BBS table
Write	COM port address to BIOS Data Area (BDA)
BDA	at 0x400: COM port table at 0x400+0x00, LPT at 0x400+0x08
Parse	BBS table for boot device
Execute	INT 19h via CSM16 thunk
Status	= CsmThunk16Entry (
Attempt	boot from unconventional devices (USB, network, etc.)
Try	each boot device type
Update	keyboard LED status in BDA
BDA	offset 0x417 bit 5-3: keyboard LED flags
Prepare	to boot EFI: save legacy state, restore EFI state
Shadow	all discovered legacy Option ROMs
The	algorithm:
Initialize	CLP (Configuration Load Protocol) support if needed
Shadow	loop
for	*(OpRomIndex = NumberOfOpRoms; OpRomIndex <* TotalSize; OpRomIndex++) {**
Execute	each ROM
Install	Legacy BIOS protocol interfaces
Set	base memory size in BDA at 0x413
Read	BBS count and table from CSM context
Save	memory map data to lockbox
Status	= gBS->GetMemoryMap (
Original	code calls a specific DebugPrint implementation
that	writes to the serial port / console
DebugPrint	(Level, Format, VaList);
Original	code calls ASSERT via DebugLib
ASSERT	(Description);
The	driver registers a ComponentName2 protocol at gCsmComponentName2.
These	structures are generated by the UEFI driver framework.

Generated by HR650X BIOS Decompilation Project