| 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 DetectPrint_RomFoundAtSegment
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| 73 | call RamVars_Initialize
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| 74 | call Interrupts_InitializeInterruptVectors
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| 75 | call DetectDrives_FromAllIDEControllers
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| 76 | ; Fall to .StoreDptPointersToIntVectors
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| 77 |
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| 78 | ;--------------------------------------------------------------------
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| 79 | ; .StoreDptPointersToIntVectors
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| 80 | ; Parameters:
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| 81 | ; DS: RAMVARS segment
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| 82 | ; ES: BDA and interrupt vector segment (zero)
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| 83 | ; Returns:
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| 84 | ; Nothing
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| 85 | ; Corrupts registers:
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| 86 | ; DX, DI
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| 87 | ;--------------------------------------------------------------------
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| 88 | .StoreDptPointersToIntVectors:
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| 89 | mov dl, 80h
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| 90 | call FindDPT_ForDriveNumber ; DPT to DS:DI
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| 91 | jnc SHORT .FindForDrive81h ; Store nothing if not our drive
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| 92 | mov [es:INTV_HD0DPT*4], di
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| 93 | mov [es:INTV_HD0DPT*4+2], ds
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| 94 | .FindForDrive81h:
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| 95 | inc dx
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| 96 | call FindDPT_ForDriveNumber
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| 97 | jnc SHORT .ResetDetectedDrives
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| 98 | mov [es:INTV_HD1DPT*4], di
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| 99 | mov [es:INTV_HD1DPT*4+2], ds
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| 100 | ; Fall to .ResetDetectedDrives
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| 101 |
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| 102 | ;--------------------------------------------------------------------
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| 103 | ; .ResetDetectedDrives
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| 104 | ; Parameters:
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| 105 | ; DS: RAMVARS segment
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| 106 | ; Returns:
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| 107 | ; Nothing
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| 108 | ; Corrupts registers:
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| 109 | ; AX, BX, CX, DX, DI
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| 110 | ;--------------------------------------------------------------------
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| 111 | .ResetDetectedDrives:
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| 112 | jmp AH0h_ResetHardDisksHandledByOurBIOS
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