BlSupportSmm.c File Reference

#include <BlSupportSmm.h>

Go to the source code of this file.

Functions
EFI_STATUS	SaveSmmInfoForS3 (IN UINT8 BlSwSmiHandlerInput)
PLD_GENERIC_REGISTER *	GetRegisterById (UINT64 Id)
VOID	LockSmiGlobalEn (VOID)
VOID	SmmFeatureLockOnS3 (VOID)
VOID EFIAPI	SetSmrr (IN VOID *ProcedureArgument)
VOID	SetSmrrOnS3 (VOID)
EFI_STATUS EFIAPI	BlSwSmiHandler (IN EFI_HANDLE DispatchHandle, IN CONST VOID *Context, IN OUT VOID *CommBuffer, IN OUT UINTN *CommBufferSize)
EFI_STATUS EFIAPI	BlSupportSmmReadyToLockCallback (IN CONST EFI_GUID *Protocol, IN VOID *Interface, IN EFI_HANDLE Handle)
EFI_STATUS EFIAPI	BlSupportSmm (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

Variables
PLD_S3_COMMUNICATION	mPldS3Hob
EFI_SMRAM_HOB_DESCRIPTOR_BLOCK *	mSmramHob = NULL
PLD_SMM_REGISTERS *	mSmmRegisterHob = NULL
UINT64	mSmmFeatureControl = 0

Detailed Description

This driver is used for SMM S3 support for the bootloader that doesn't support SMM. The payload would save SMM rebase info to SMM communication area. The bootloader is expected to rebase the SMM and trigger SMI by writting 0xB2 port with given value from SMM communication area. The paylaod SMM handler got chance to restore regs in S3 path.

Copyright (c) 2021, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file BlSupportSmm.c.

Function Documentation

BlSupportSmm()

EFI_STATUS EFIAPI BlSupportSmm	(	IN EFI_HANDLE	ImageHandle,
		IN EFI_SYSTEM_TABLE *	SystemTable
	)

The driver's entry point.

Parameters

[in]	ImageHandle	The firmware allocated handle for the EFI image.
[in]	SystemTable	A pointer to the EFI System Table.

Return values

EFI_SUCCESS	The entry point is executed successfully.
Others	Some error occurs when executing this entry point.

Definition at line 345 of file BlSupportSmm.c.

BlSupportSmmReadyToLockCallback()

EFI_STATUS EFIAPI BlSupportSmmReadyToLockCallback	(	IN CONST EFI_GUID *	Protocol,
		IN VOID *	Interface,
		IN EFI_HANDLE	Handle
	)

Lock SMI in this SMM ready to lock event.

Parameters

Protocol	Points to the protocol's unique identifier
Interface	Points to the interface instance
Handle	The handle on which the interface was installed

Return values

EFI_SUCCESS	SmmEventCallback runs successfully
EFI_NOT_FOUND	The Fvb protocol for variable is not found.

Definition at line 320 of file BlSupportSmm.c.

BlSwSmiHandler()

EFI_STATUS EFIAPI BlSwSmiHandler	(	IN EFI_HANDLE	DispatchHandle,
		IN CONST VOID *	Context,
		IN OUT VOID *	CommBuffer,
		IN OUT UINTN *	CommBufferSize
	)

Software SMI callback for restoring SMRR base and mask in S3 path.

Parameters

[in]	DispatchHandle	The unique handle assigned to this handler by SmiHandlerRegister().
[in]	Context	Points to an optional handler context which was specified when the handler was registered.
[in,out]	CommBuffer	A pointer to a collection of data in memory that will be conveyed from a non-SMM environment into an SMM environment.
[in,out]	CommBufferSize	The size of the CommBuffer.

Return values

EFI_SUCCESS

The interrupt was handled successfully.

Definition at line 294 of file BlSupportSmm.c.

GetRegisterById()

PLD_GENERIC_REGISTER * GetRegisterById

(

UINT64

Id

)

Get specified SMI register based on given register ID

Parameters

[in]

Id

The register ID to get.

Return values

NULL	The register is not found

Returns

smi register

Definition at line 112 of file BlSupportSmm.c.

LockSmiGlobalEn()

VOID LockSmiGlobalEn

(

VOID

)

Set SMM SMI Global enable lock

Definition at line 132 of file BlSupportSmm.c.

SaveSmmInfoForS3()

EFI_STATUS SaveSmmInfoForS3

(

IN UINT8

BlSwSmiHandlerInput

)

Save SMM rebase and SMI handler information to SMM communication area

The function detects SMM communication region for boot loader, if it is detected, it will save SMM rebase information and S3 SMI handler information to SMM communication region. Bootloader should consume these information in S3 path to restore smm base, and write the 0xB2 port to trigger SMI so that payload could resume S3 registers.

Parameters

[in]

BlSwSmiHandlerInput

Value written to 0xB2 to trigger SMI handler.

Return values

EFI_SUCCESS	Save SMM info success.
Others	Failed to save SMM info.

Definition at line 35 of file BlSupportSmm.c.

SetSmrr()

VOID EFIAPI SetSmrr

(

IN VOID *

ProcedureArgument

)

Function to program SMRR base and mask.

Parameters

[in]

ProcedureArgument

Pointer to SMRR_BASE_MASK structure.

Definition at line 195 of file BlSupportSmm.c.

SetSmrrOnS3()

VOID SetSmrrOnS3

(

VOID

)

Set SMRR in S3 path.

Definition at line 210 of file BlSupportSmm.c.

SmmFeatureLockOnS3()

VOID SmmFeatureLockOnS3

(

VOID

)

Check and set SMM feature lock bit and code check enable bit in S3 path.

Definition at line 169 of file BlSupportSmm.c.

Variable Documentation

mPldS3Hob

PLD_S3_COMMUNICATION mPldS3Hob

Definition at line 16 of file BlSupportSmm.c.

mSmmFeatureControl

UINT64 mSmmFeatureControl = 0

Definition at line 19 of file BlSupportSmm.c.

mSmmRegisterHob

PLD_SMM_REGISTERS* mSmmRegisterHob = NULL

Definition at line 18 of file BlSupportSmm.c.

mSmramHob

EFI_SMRAM_HOB_DESCRIPTOR_BLOCK* mSmramHob = NULL

Definition at line 17 of file BlSupportSmm.c.