1 /** @file 2 This code fills in standard CMOS values and updates the standard CMOS 3 checksum. The Legacy16 code or LegacyBiosPlatform.c is responsible for 4 non-standard CMOS locations and non-standard checksums. 5 6 Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR> 7 8 This program and the accompanying materials 9 are licensed and made available under the terms and conditions 10 of the BSD License which accompanies this distribution. The 11 full text of the license may be found at 12 http://opensource.org/licenses/bsd-license.php 13 14 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 15 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 16 17 **/ 18 19 #include "LegacyBiosInterface.h" 20 21 /** 22 Read CMOS register through index/data port. 23 24 @param[in] Index The index of the CMOS register to read. 25 26 @return The data value from the CMOS register specified by Index. 27 28 **/ 29 UINT8 30 LegacyReadStandardCmos ( 31 IN UINT8 Index 32 ) 33 { 34 IoWrite8 (PORT_70, Index); 35 return IoRead8 (PORT_71); 36 } 37 38 /** 39 Write CMOS register through index/data port. 40 41 @param[in] Index The index of the CMOS register to write. 42 @param[in] Value The value of CMOS register to write. 43 44 @return The value written to the CMOS register specified by Index. 45 46 **/ 47 UINT8 48 LegacyWriteStandardCmos ( 49 IN UINT8 Index, 50 IN UINT8 Value 51 ) 52 { 53 IoWrite8 (PORT_70, Index); 54 return IoWrite8 (PORT_71, Value); 55 } 56 57 /** 58 Calculate the new standard CMOS checksum and write it. 59 60 @param Private Legacy BIOS Instance data 61 62 @retval EFI_SUCCESS Calculate 16-bit checksum successfully 63 64 **/ 65 EFI_STATUS 66 LegacyCalculateWriteStandardCmosChecksum ( 67 VOID 68 ) 69 { 70 UINT8 Register; 71 UINT16 Checksum; 72 73 for (Checksum = 0, Register = 0x10; Register < 0x2e; Register++) { 74 Checksum = (UINT16)(Checksum + LegacyReadStandardCmos (Register)); 75 } 76 LegacyWriteStandardCmos (CMOS_2E, (UINT8)(Checksum >> 8)); 77 LegacyWriteStandardCmos (CMOS_2F, (UINT8)(Checksum & 0xff)); 78 return EFI_SUCCESS; 79 } 80 81 82 /** 83 Fill in the standard CMOS stuff before Legacy16 load 84 85 @param Private Legacy BIOS Instance data 86 87 @retval EFI_SUCCESS It should always work. 88 89 **/ 90 EFI_STATUS 91 LegacyBiosInitCmos ( 92 IN LEGACY_BIOS_INSTANCE *Private 93 ) 94 { 95 UINT32 Size; 96 97 // 98 // Clear all errors except RTC lost power 99 // 100 LegacyWriteStandardCmos (CMOS_0E, (UINT8)(LegacyReadStandardCmos (CMOS_0E) & BIT7)); 101 102 // 103 // Update CMOS locations 15,16,17,18,30,31 and 32 104 // CMOS 16,15 = 640Kb = 0x280 105 // CMOS 18,17 = 31,30 = 15Mb max in 1Kb increments =0x3C00 max 106 // CMOS 32 = 0x20 107 // 108 LegacyWriteStandardCmos (CMOS_15, 0x80); 109 LegacyWriteStandardCmos (CMOS_16, 0x02); 110 111 Size = 15 * SIZE_1MB; 112 if (Private->IntThunk->EfiToLegacy16InitTable.OsMemoryAbove1Mb < (15 * SIZE_1MB)) { 113 Size = Private->IntThunk->EfiToLegacy16InitTable.OsMemoryAbove1Mb >> 10; 114 } 115 116 LegacyWriteStandardCmos (CMOS_17, (UINT8)(Size & 0xFF)); 117 LegacyWriteStandardCmos (CMOS_30, (UINT8)(Size & 0xFF)); 118 LegacyWriteStandardCmos (CMOS_18, (UINT8)(Size >> 8)); 119 LegacyWriteStandardCmos (CMOS_31, (UINT8)(Size >> 8)); 120 121 LegacyCalculateWriteStandardCmosChecksum (); 122 123 return EFI_SUCCESS; 124 } 125
