sravan/system76-edk2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

PcAtChipsetPkg: Add MMIO Support to RTC driver

Browse Source 
Some virtual machine managers like Kvmtool emulate the MC146818
RTC controller in the MMIO space so that architectures that do
not support I/O Mapped I/O can use the RTC. This patch adds MMIO
support to the RTC controller driver.

The PCD PcdRtcUseMmio has been added to select I/O or MMIO support.
  If PcdRtcUseMmio is:
    TRUE  - Indicates the RTC port registers are in MMIO space.
    FALSE - Indicates the RTC port registers are in I/O space.
            Default is I/O space.

Additionally two new PCDs PcdRtcIndexRegister64 and
PcdRtcTargetRegister64 have been introduced to provide the base
address for the RTC registers in the MMIO space.

When MMIO support is selected (PcdRtcUseMmio == TRUE) the driver
converts the pointers to the RTC MMIO registers so that the
RTC registers are accessible post ExitBootServices.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Sami Mujawar
2020-10-02 22:13:55 +01:00
committed by mergify[bot]
parent a7d977040b
commit 015be4075f
4 changed files with 187 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntimeDxe.inf
View File

@@ -6,6 +6,7 @@
#
# Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
# Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
# Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.<BR>
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
@@ -61,6 +62,11 @@
## SOMETIMES_CONSUMES ## SystemTable
gEfiAcpiTableGuid
gEfiEventVirtualAddressChangeGuid
[FeaturePcd]
gPcAtChipsetPkgTokenSpaceGuid.PcdRtcUseMmio ## CONSUMES
[FixedPcd]
gPcAtChipsetPkgTokenSpaceGuid.PcdInitialValueRtcRegisterA ## CONSUMES
gPcAtChipsetPkgTokenSpaceGuid.PcdInitialValueRtcRegisterB ## CONSUMES
@@ -72,6 +78,8 @@
gPcAtChipsetPkgTokenSpaceGuid.PcdMaximalValidYear ## CONSUMES
gPcAtChipsetPkgTokenSpaceGuid.PcdRtcIndexRegister ## CONSUMES
gPcAtChipsetPkgTokenSpaceGuid.PcdRtcTargetRegister ## CONSUMES
gPcAtChipsetPkgTokenSpaceGuid.PcdRtcIndexRegister64 ## CONSUMES
gPcAtChipsetPkgTokenSpaceGuid.PcdRtcTargetRegister64 ## CONSUMES
[Depex]
gEfiVariableArchProtocolGuid AND gEfiVariableWriteArchProtocolGuid