1 | ; Project name : XTIDE Universal BIOS
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2 | ; Description : Functions for initializing the BIOS.
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3 |
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4 | ; Section containing code
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5 | SECTION .text
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6 |
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7 | ;--------------------------------------------------------------------
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8 | ; Initializes the BIOS.
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9 | ; This function is called from main BIOS ROM search routine.
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10 | ;
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11 | ; Initialize_FromMainBiosRomSearch
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12 | ; Parameters:
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13 | ; Nothing
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14 | ; Returns:
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15 | ; Nothing
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16 | ; Corrupts registers:
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17 | ; Nothing
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18 | ;--------------------------------------------------------------------
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19 | Initialize_FromMainBiosRomSearch:
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20 | pushf
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21 | push es
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22 | push ds
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23 | ePUSHA
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24 |
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25 | LOAD_BDA_SEGMENT_TO es, ax
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26 | call Initialize_ShouldSkip
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27 | jnz SHORT .SkipRomInitialization
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28 |
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29 | %ifdef USE_AT ; Early initialization on AT build
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30 | call Initialize_AndDetectDrives
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31 | %else ; Late initialization on XT builds
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32 | call Int19hLate_InitializeInt19h
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33 | %endif
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34 | .SkipRomInitialization:
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35 | ePOPA
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36 | pop ds
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37 | pop es
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38 | popf
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39 | retf
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40 |
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41 |
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42 | ;--------------------------------------------------------------------
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43 | ; Checks if user wants to skip ROM initialization.
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44 | ;
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45 | ; Initialize_ShouldSkip
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46 | ; Parameters:
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47 | ; ES: BDA segment
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48 | ; Returns:
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49 | ; ZF: Cleared if ROM initialization is to be skipped
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50 | ; Set to continue ROM initialization
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51 | ; Corrupts registers:
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52 | ; Nothing
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53 | ;--------------------------------------------------------------------
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54 | Initialize_ShouldSkip:
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55 | sti ; Enable interrupts
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56 | test BYTE [es:BDA.bKBFlgs1], (1<<2) ; Clear ZF if CTRL is held down
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57 | ret
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58 |
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59 |
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60 | ;--------------------------------------------------------------------
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61 | ; Initializes the BIOS variables and detects IDE drives.
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62 | ;
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63 | ; Initialize_AndDetectDrives
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64 | ; Parameters:
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65 | ; ES: BDA Segment
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66 | ; Returns:
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67 | ; DS: RAMVARS segment
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68 | ; Corrupts registers:
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69 | ; All
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70 | ;--------------------------------------------------------------------
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71 | Initialize_AndDetectDrives:
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72 | call BootMenuPrint_InitializeDisplayContext
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73 | call DetectPrint_RomFoundAtSegment
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74 | call RamVars_Initialize
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75 | call Interrupts_InitializeInterruptVectors
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76 | call DetectDrives_FromAllIDEControllers
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77 | ; Fall to .StoreDptPointersToIntVectors
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78 |
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79 | ;--------------------------------------------------------------------
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80 | ; .StoreDptPointersToIntVectors
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81 | ; Parameters:
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82 | ; DS: RAMVARS segment
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83 | ; ES: BDA and interrupt vector segment (zero)
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84 | ; Returns:
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85 | ; Nothing
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86 | ; Corrupts registers:
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87 | ; DX, DI
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88 | ;--------------------------------------------------------------------
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89 | .StoreDptPointersToIntVectors:
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90 | mov dl, 80h
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91 | call FindDPT_ForDriveNumber ; DPT to DS:DI
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92 | jnc SHORT .FindForDrive81h ; Store nothing if not our drive
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93 | mov [es:INTV_HD0DPT*4], di
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94 | mov [es:INTV_HD0DPT*4+2], ds
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95 | .FindForDrive81h:
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96 | inc dx
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97 | call FindDPT_ForDriveNumber
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98 | jnc SHORT .ResetDetectedDrives
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99 | mov [es:INTV_HD1DPT*4], di
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100 | mov [es:INTV_HD1DPT*4+2], ds
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101 | ; Fall to .ResetDetectedDrives
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102 |
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103 | ;--------------------------------------------------------------------
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104 | ; .ResetDetectedDrives
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105 | ; Parameters:
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106 | ; DS: RAMVARS segment
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107 | ; Returns:
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108 | ; Nothing
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109 | ; Corrupts registers:
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110 | ; All
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111 | ;--------------------------------------------------------------------
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112 | .ResetDetectedDrives:
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113 | call Idepack_FakeToSSBP
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114 | call AH0h_ResetHardDisksHandledByOurBIOS
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115 | add sp, BYTE SIZE_OF_FAKE_IDEPACK
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116 | ret
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