PcRtc

Field	Value
Index	0034
Module	PcRtc
Image	PcRtc.efi
Size	16,384 bytes (5 sections, PE32+)
SHA256	64ce22dcd9beff0a0dcdaffad292ce9d508..
Subsystem	Runtime Driver (0Ch)
Functions	~15

Overview

PC-AT Real-Time Clock Runtime DXE driver that implements the standard EFI RealTimeClock services (GetTime, SetTime, GetWakeupTime, SetWakeupTime) by directly accessing the MC146818-compatible CMOS RTC hardware via legacy I/O ports 0x70/0x71. Derived from PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe and installed as a UEFI Runtime Driver (0Ch), meaning its services remain available after ExitBootServices().

Key Functions

PcRtcEntryPoint -- initializes the RTC arch protocol and registers time services
PcRtcGetTime -- reads current time from CMOS RTC registers
PcRtcSetTime -- writes time to CMOS RTC registers
PcRtcGetWakeupTime -- reads alarm/wakeup time from CMOS
PcRtcSetWakeupTime -- sets alarm/wakeup time in CMOS

Dependencies

RTC Architecture Protocol (27CFAC87-46CC-11D4-9A38-0090273FC14D)
DXE Services Table
HOB List GUID
Legacy I/O ports 0x70 (index, NMI bit 7) / 0x71 (data)

Platform

Lenovo HR650X, Purley platform. Standard MC146818 RTC.