Files
system76-edk2/OvmfPkg/Library/PlatformInitLib/Cmos.c
Min Xu 57bcfc3b06 OvmfPkg: Create initial version of PlatformInitLib
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3863

There are 3 variants of PlatformPei in OvmfPkg:
 - OvmfPkg/PlatformPei
 - OvmfPkg/XenPlatformPei
 - OvmfPkg/Bhyve/PlatformPei/PlatformPei.inf
These PlatformPeis can share many common codes, such as
Cmos / Hob / Memory / Platform related functions. This commit
(and its following several patches) are to create a PlatformInitLib
which wraps the common code called in above PlatformPeis.

In this initial version of PlatformInitLib, below Cmos related functions
are introduced:
 - PlatformCmosRead8
 - PlatformCmosWrite8
 - PlatformDebugDumpCmos

They correspond to the functions in OvmfPkg/PlatformPei:
 - CmosRead8
 - CmosWrite8
 - DebugDumpCmos

Considering this PlatformInitLib will be used in SEC phase, global
variables and dynamic PCDs are avoided. We use PlatformInfoHob
to exchange information between functions.

EFI_HOB_PLATFORM_INFO is the data struct which contains the platform
information, such as HostBridgeDevId, BootMode, S3Supported,
SmmSmramRequire, etc.

After PlatformInitLib is created, OvmfPkg/PlatformPei is refactored
with this library.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
2022-04-02 08:15:12 +00:00

82 lines
1.5 KiB
C

/** @file
PC/AT CMOS access routines
Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/PlatformInitLib.h>
#include <Library/DebugLib.h>
#include "Library/IoLib.h"
/**
Reads 8-bits of CMOS data.
Reads the 8-bits of CMOS data at the location specified by Index.
The 8-bit read value is returned.
@param Index The CMOS location to read.
@return The value read.
**/
UINT8
EFIAPI
PlatformCmosRead8 (
IN UINTN Index
)
{
IoWrite8 (0x70, (UINT8)Index);
return IoRead8 (0x71);
}
/**
Writes 8-bits of CMOS data.
Writes 8-bits of CMOS data to the location specified by Index
with the value specified by Value and returns Value.
@param Index The CMOS location to write.
@param Value The value to write to CMOS.
@return The value written to CMOS.
**/
UINT8
EFIAPI
PlatformCmosWrite8 (
IN UINTN Index,
IN UINT8 Value
)
{
IoWrite8 (0x70, (UINT8)Index);
IoWrite8 (0x71, Value);
return Value;
}
/**
Dump the CMOS content
*/
VOID
EFIAPI
PlatformDebugDumpCmos (
VOID
)
{
UINT32 Loop;
DEBUG ((DEBUG_INFO, "CMOS:\n"));
for (Loop = 0; Loop < 0x80; Loop++) {
if ((Loop % 0x10) == 0) {
DEBUG ((DEBUG_INFO, "%02x:", Loop));
}
DEBUG ((DEBUG_INFO, " %02x", PlatformCmosRead8 (Loop)));
if ((Loop % 0x10) == 0xf) {
DEBUG ((DEBUG_INFO, "\n"));
}
}
}