S3SaveStateDxe

Index	Module	Size	Phase
288	S3SaveStateDxe	23,200 bytes (22.7 KB)	DXE

Overview

S3 Save State DXE Driver that preserves ACPI S3 resume context during the DXE phase. This module saves the FACS address, IDTR profile, and page tables into the SMM LockBox, and provides the EFI_S3_SAVE_STATE protocol for recording boot script entries. On SmmReadyToLock, it transitions the boot script buffer to SMM-owned memory and registers both S3 Save State and S3 SMM Save State protocol notifications.

Key Functions

DriverEntryPoint -- Main DXE entry; initializes globals, schedules AcpiS3ContextInitialize, installs EFI S3 Save State protocol
AcpiS3ContextInitialize -- Timer callback that locates FACS, builds IDTR profile, allocates NVS page table, saves ACPI S3 context into LockBox
LocateAcpiFacsTable -- Searches ACPI tables (RSDP/XSDT/RSDT/FADT) for the FACS table
AllocateS3NvsPageTable -- Allocates and builds the S3 resume page table (NX-compatible, self-referencing)
BootScriptTableInit -- Initializes the boot script descriptor table and sets up SMM communication
BootScriptBufferGrow -- Grows the boot script table when capacity is exhausted
BootScriptClose -- Finalizes boot script entries and transitions buffer ownership
BootScriptResync -- Re-synchronizes boot script state from LockBox after SMM takes ownership
SaveLockBox / RestoreLockBox / UpdateLockBox -- SMM LockBox operations for boot script persistence
ScriptIoWriteEntry / ScriptIoReadWriteEntry / ScriptMemWriteEntry / ScriptMemReadWriteEntry -- Boot script entry creators for I/O and memory access
ScriptPciCfgWriteEntry / ScriptPciCfgReadWriteEntry / ScriptPciCfg2WriteEntry -- Boot script entries for PCI configuration space
ScriptSmbusExecuteEntry -- Boot script entry for SMBus transactions
ScriptPollInsert -- Boot script poll-until-match entry
ScriptDispatchEntry / ScriptInformationEntry -- Dispatch and informational boot script entries

Dependencies

UEFI Boot Services, UEFI Runtime Services, ACPI Tables (FACS, FADT), SMM Communication Protocol, LockBox Protocol, PCD Protocol, HOB List

Platform

Lenovo HR650X (Purley/LBG-PCH), X64