mirror of https://github.com/acidanthera/audk.git
118 lines
2.9 KiB
C
118 lines
2.9 KiB
C
/** @file
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This code fills in standard CMOS values and updates the standard CMOS
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checksum. The Legacy16 code or LegacyBiosPlatform.c is responsible for
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non-standard CMOS locations and non-standard checksums.
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Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#include "LegacyBiosInterface.h"
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/**
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Read CMOS register through index/data port.
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@param[in] Index The index of the CMOS register to read.
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@return The data value from the CMOS register specified by Index.
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**/
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UINT8
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LegacyReadStandardCmos (
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IN UINT8 Index
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)
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{
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IoWrite8 (PORT_70, Index);
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return IoRead8 (PORT_71);
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}
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/**
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Write CMOS register through index/data port.
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@param[in] Index The index of the CMOS register to write.
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@param[in] Value The value of CMOS register to write.
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@return The value written to the CMOS register specified by Index.
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**/
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UINT8
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LegacyWriteStandardCmos (
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IN UINT8 Index,
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IN UINT8 Value
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)
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{
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IoWrite8 (PORT_70, Index);
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return IoWrite8 (PORT_71, Value);
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}
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/**
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Calculate the new standard CMOS checksum and write it.
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@param Private Legacy BIOS Instance data
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@retval EFI_SUCCESS Calculate 16-bit checksum successfully
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**/
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EFI_STATUS
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LegacyCalculateWriteStandardCmosChecksum (
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VOID
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)
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{
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UINT8 Register;
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UINT16 Checksum;
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for (Checksum = 0, Register = 0x10; Register < 0x2e; Register++) {
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Checksum = (UINT16)(Checksum + LegacyReadStandardCmos (Register));
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}
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LegacyWriteStandardCmos (CMOS_2E, (UINT8)(Checksum >> 8));
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LegacyWriteStandardCmos (CMOS_2F, (UINT8)(Checksum & 0xff));
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return EFI_SUCCESS;
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}
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/**
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Fill in the standard CMOS stuff before Legacy16 load
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@param Private Legacy BIOS Instance data
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@retval EFI_SUCCESS It should always work.
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**/
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EFI_STATUS
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LegacyBiosInitCmos (
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IN LEGACY_BIOS_INSTANCE *Private
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)
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{
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UINT32 Size;
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//
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// Clear all errors except RTC lost power
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//
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LegacyWriteStandardCmos (CMOS_0E, (UINT8)(LegacyReadStandardCmos (CMOS_0E) & BIT7));
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//
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// Update CMOS locations 15,16,17,18,30,31 and 32
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// CMOS 16,15 = 640Kb = 0x280
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// CMOS 18,17 = 31,30 = 15Mb max in 1Kb increments =0x3C00 max
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// CMOS 32 = 0x20
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//
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LegacyWriteStandardCmos (CMOS_15, 0x80);
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LegacyWriteStandardCmos (CMOS_16, 0x02);
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Size = 15 * SIZE_1MB;
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if (Private->IntThunk->EfiToLegacy16InitTable.OsMemoryAbove1Mb < (15 * SIZE_1MB)) {
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Size = Private->IntThunk->EfiToLegacy16InitTable.OsMemoryAbove1Mb >> 10;
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}
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LegacyWriteStandardCmos (CMOS_17, (UINT8)(Size & 0xFF));
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LegacyWriteStandardCmos (CMOS_30, (UINT8)(Size & 0xFF));
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LegacyWriteStandardCmos (CMOS_18, (UINT8)(Size >> 8));
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LegacyWriteStandardCmos (CMOS_31, (UINT8)(Size >> 8));
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LegacyCalculateWriteStandardCmosChecksum ();
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return EFI_SUCCESS;
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}
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