[90] | 1 | ; Project name : XTIDE Universal BIOS |
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[33] | 2 | ; Description : Functions for initializing the BIOS. |
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| 3 | |
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[376] | 4 | ; |
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[491] | 5 | ; XTIDE Universal BIOS and Associated Tools |
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[526] | 6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team. |
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[376] | 7 | ; |
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| 8 | ; This program is free software; you can redistribute it and/or modify |
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| 9 | ; it under the terms of the GNU General Public License as published by |
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| 10 | ; the Free Software Foundation; either version 2 of the License, or |
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| 11 | ; (at your option) any later version. |
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[491] | 12 | ; |
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[376] | 13 | ; This program is distributed in the hope that it will be useful, |
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| 14 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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[491] | 16 | ; GNU General Public License for more details. |
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[376] | 17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
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[491] | 18 | ; |
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[376] | 19 | |
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[33] | 20 | ; Section containing code |
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| 21 | SECTION .text |
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| 22 | |
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| 23 | ;-------------------------------------------------------------------- |
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[580] | 24 | ; Drives must be detected before this function is called unless |
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| 25 | ; MODULE_DRIVEXLATE has been included in the BIOS. |
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[431] | 26 | ; |
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[33] | 27 | ; Interrupts_InitializeInterruptVectors |
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| 28 | ; Parameters: |
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| 29 | ; DS: RAMVARS segment |
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| 30 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 31 | ; Returns: |
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| 32 | ; Nothing |
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| 33 | ; Corrupts registers: |
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| 34 | ; All except segments |
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[86] | 35 | ;-------------------------------------------------------------------- |
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[33] | 36 | Interrupts_InitializeInterruptVectors: |
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[431] | 37 | ; Install INT 19h handler to properly reset the system |
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| 38 | mov al, BIOS_BOOT_LOADER_INTERRUPT_19h ; INT 19h interrupt vector offset |
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| 39 | mov si, Int19hReset_Handler ; INT 19h handler to reboot the system |
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| 40 | call Interrupts_InstallHandlerToVectorInALFromCSSI |
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| 41 | |
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| 42 | ; If no drives detected, leave system INT 13h and 40h handlers |
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| 43 | ; in place. We need our INT 13h handler to swap drive letters. |
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[492] | 44 | %ifndef MODULE_DRIVEXLATE |
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[431] | 45 | cmp BYTE [RAMVARS.bDrvCnt], 0 |
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[489] | 46 | je SHORT Interrupts_InstallHandlerToVectorInALFromCSSI.Interrupts_Return |
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[431] | 47 | %endif |
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[97] | 48 | ; Fall to .InitializeInt13hAnd40h |
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[33] | 49 | |
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| 50 | ;-------------------------------------------------------------------- |
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[97] | 51 | ; .InitializeInt13hAnd40h |
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[33] | 52 | ; Parameters: |
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| 53 | ; DS: RAMVARS segment |
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| 54 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 55 | ; Returns: |
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| 56 | ; Nothing |
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| 57 | ; Corrupts registers: |
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| 58 | ; AX, BX, CX, DX, SI, DI |
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[86] | 59 | ;-------------------------------------------------------------------- |
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[97] | 60 | .InitializeInt13hAnd40h: |
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[181] | 61 | mov ax, [es:BIOS_DISK_INTERRUPT_13h*4+2]; Load old INT 13h segment |
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| 62 | mov [RAMVARS.fpOldI13h+2], ax ; Store old INT 13h segment |
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| 63 | xchg dx, ax |
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[152] | 64 | mov ax, [es:BIOS_DISK_INTERRUPT_13h*4] ; Load old INT 13h offset |
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[33] | 65 | mov [RAMVARS.fpOldI13h], ax ; Store old INT 13h offset |
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[181] | 66 | |
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[33] | 67 | ; Only store INT 13h handler to 40h if 40h is not already installed. |
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| 68 | ; At least AMI BIOS for 286 stores 40h handler by itself and calls |
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[530] | 69 | ; 40h from 13h. That system locks to infinite loop if we blindly copy 13h to 40h. |
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[33] | 70 | call FloppyDrive_IsInt40hInstalled |
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[243] | 71 | jc SHORT .Int40hAlreadyInstalled |
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[152] | 72 | mov [es:BIOS_DISKETTE_INTERRUPT_40h*4], ax ; Store old INT 13h offset |
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| 73 | mov [es:BIOS_DISKETTE_INTERRUPT_40h*4+2], dx ; Store old INT 13h segment |
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[243] | 74 | .Int40hAlreadyInstalled: |
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[258] | 75 | |
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| 76 | mov al, BIOS_DISK_INTERRUPT_13h ; INT 13h interrupt vector offset |
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[522] | 77 | %ifdef RELOCATE_INT13H_STACK |
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| 78 | mov si, Int13h_DiskFunctionsHandlerWithStackChange |
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| 79 | %else |
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[417] | 80 | mov si, Int13h_DiskFunctionsHandler |
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| 81 | %endif |
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[392] | 82 | |
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[398] | 83 | %ifndef MODULE_IRQ |
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| 84 | ; Fall to Interrupts_InstallHandlerToVectorInALFromCSSI |
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| 85 | %else |
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[392] | 86 | call Interrupts_InstallHandlerToVectorInALFromCSSI |
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[97] | 87 | ; Fall to .InitializeHardwareIrqHandlers |
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[33] | 88 | |
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| 89 | ;-------------------------------------------------------------------- |
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[97] | 90 | ; .InitializeHardwareIrqHandlers |
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[33] | 91 | ; Parameters: |
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| 92 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 93 | ; Returns: |
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| 94 | ; Nothing |
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| 95 | ; Corrupts registers: |
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[258] | 96 | ; BX, CX, DX, SI, DI, AX |
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[86] | 97 | ;-------------------------------------------------------------------- |
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[97] | 98 | .InitializeHardwareIrqHandlers: |
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[33] | 99 | call RamVars_GetIdeControllerCountToCX |
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[558] | 100 | mov di, ROMVARS.ideVars0+IDEVARS.bIRQ |
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[33] | 101 | .IdeControllerLoop: |
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[491] | 102 | mov al, [cs:di] |
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[33] | 103 | add di, BYTE IDEVARS_size ; Increment to next controller |
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| 104 | call .InstallLowOrHighIrqHandler |
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| 105 | loop .IdeControllerLoop |
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[86] | 106 | .Return: |
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| 107 | ret ; This ret is shared with .InstallLowOrHighIrqHandler |
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[33] | 108 | |
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| 109 | ;-------------------------------------------------------------------- |
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| 110 | ; .InstallLowOrHighIrqHandler |
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| 111 | ; Parameters: |
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[258] | 112 | ; AL: IRQ number, 0 if IRQ disabled |
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[33] | 113 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 114 | ; Returns: |
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| 115 | ; Nothing |
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| 116 | ; Corrupts registers: |
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| 117 | ; BX, SI |
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[86] | 118 | ;-------------------------------------------------------------------- |
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[33] | 119 | .InstallLowOrHighIrqHandler: |
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[258] | 120 | test al, al |
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[86] | 121 | jz SHORT .Return ; IRQ not used |
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[540] | 122 | %ifdef USE_AT |
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[258] | 123 | cmp al, 8 |
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[86] | 124 | jb SHORT .InstallLowIrqHandler |
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[162] | 125 | ; Fall to .InstallHighIrqHandler |
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[33] | 126 | |
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| 127 | ;-------------------------------------------------------------------- |
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| 128 | ; .InstallHighIrqHandler |
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| 129 | ; Parameters: |
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| 130 | ; BX: IRQ number (8...15) |
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| 131 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 132 | ; Returns: |
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| 133 | ; Nothing |
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| 134 | ; Corrupts registers: |
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[258] | 135 | ; AL, BX, SI |
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[86] | 136 | ;-------------------------------------------------------------------- |
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[97] | 137 | .InstallHighIrqHandler: |
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[258] | 138 | add al, BYTE HARDWARE_IRQ_8_INTERRUPT_70h - 8 ; Interrupt vector number |
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[150] | 139 | mov si, IdeIrq_InterruptServiceRoutineForIrqs8to15 |
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[258] | 140 | jmp SHORT Interrupts_InstallHandlerToVectorInALFromCSSI |
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[540] | 141 | %endif ; USE_AT |
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[33] | 142 | |
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| 143 | ;-------------------------------------------------------------------- |
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| 144 | ; .InstallLowIrqHandler |
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| 145 | ; Parameters: |
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[258] | 146 | ; AL: IRQ number (0...7) |
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[33] | 147 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 148 | ; Returns: |
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| 149 | ; Nothing |
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| 150 | ; Corrupts registers: |
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[258] | 151 | ; AL, BX, SI |
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[86] | 152 | ;-------------------------------------------------------------------- |
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[33] | 153 | .InstallLowIrqHandler: |
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[258] | 154 | add al, BYTE HARDWARE_IRQ_0_INTERRUPT_08h ; Interrupt vector number |
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[150] | 155 | mov si, IdeIrq_InterruptServiceRoutineForIrqs2to7 |
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[258] | 156 | ; Fall to Interrupts_InstallHandlerToVectorInALFromCSSI |
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[398] | 157 | %endif ; MODULE_IRQ |
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[33] | 158 | |
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| 159 | |
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| 160 | ;-------------------------------------------------------------------- |
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[258] | 161 | ; Interrupts_InstallHandlerToVectorInALFromCSSI |
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[33] | 162 | ; Parameters: |
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[258] | 163 | ; AL: Interrupt vector number (for example 13h) |
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[33] | 164 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 165 | ; CS:SI: Ptr to interrupt handler |
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| 166 | ; Returns: |
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| 167 | ; Nothing |
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| 168 | ; Corrupts registers: |
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[258] | 169 | ; AX, BX |
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[86] | 170 | ;-------------------------------------------------------------------- |
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[258] | 171 | Interrupts_InstallHandlerToVectorInALFromCSSI: |
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| 172 | mov bl, 4 ; Shift for DWORD offset, MUL smaller than other alternatives |
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| 173 | mul bl |
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| 174 | xchg ax, bx |
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[33] | 175 | mov [es:bx], si ; Store offset |
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| 176 | mov [es:bx+2], cs ; Store segment |
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[489] | 177 | .Interrupts_Return: |
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[33] | 178 | ret |
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| 179 | |
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| 180 | |
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[398] | 181 | %ifdef MODULE_IRQ |
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[33] | 182 | ;-------------------------------------------------------------------- |
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| 183 | ; Interrupts_UnmaskInterruptControllerForDriveInDSDI |
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| 184 | ; Parameters: |
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| 185 | ; DS:DI: Ptr to DPT |
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| 186 | ; Returns: |
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| 187 | ; Nothing |
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| 188 | ; Corrupts registers: |
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| 189 | ; AX, BX, DX |
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| 190 | ;-------------------------------------------------------------------- |
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| 191 | Interrupts_UnmaskInterruptControllerForDriveInDSDI: |
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[294] | 192 | eMOVZX bx, [di+DPT.bIdevarsOffset] |
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[33] | 193 | mov al, [cs:bx+IDEVARS.bIRQ] |
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[86] | 194 | test al, al |
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| 195 | jz SHORT .Return ; Interrupts disabled |
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[33] | 196 | cmp al, 8 |
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[86] | 197 | jb SHORT .UnmaskLowIrqController |
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[162] | 198 | ; Fall to .UnmaskHighIrqController |
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[33] | 199 | |
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| 200 | ;-------------------------------------------------------------------- |
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| 201 | ; .UnmaskHighIrqController |
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| 202 | ; Parameters: |
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| 203 | ; AL: IRQ number (8...15) |
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| 204 | ; Returns: |
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| 205 | ; Nothing |
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| 206 | ; Corrupts registers: |
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| 207 | ; AX, DX |
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| 208 | ;-------------------------------------------------------------------- |
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[97] | 209 | .UnmaskHighIrqController: |
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[33] | 210 | sub al, 8 ; Slave interrupt number |
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[152] | 211 | mov dx, SLAVE_8259_IMR |
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[33] | 212 | call .ClearBitFrom8259MaskRegister |
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| 213 | mov al, 2 ; Master IRQ 2 to allow slave IRQs |
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| 214 | ; Fall to .UnmaskLowIrqController |
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| 215 | |
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| 216 | ;-------------------------------------------------------------------- |
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| 217 | ; .UnmaskLowIrqController |
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| 218 | ; Parameters: |
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| 219 | ; AL: IRQ number (0...7) |
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| 220 | ; Returns: |
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| 221 | ; Nothing |
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| 222 | ; Corrupts registers: |
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| 223 | ; AX, DX |
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| 224 | ;-------------------------------------------------------------------- |
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| 225 | .UnmaskLowIrqController: |
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[152] | 226 | mov dx, MASTER_8259_IMR |
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[33] | 227 | ; Fall to .ClearBitFrom8259MaskRegister |
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| 228 | |
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| 229 | ;-------------------------------------------------------------------- |
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| 230 | ; .ClearBitFrom8259MaskRegister |
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| 231 | ; Parameters: |
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| 232 | ; AL: 8259 interrupt index (0...7) |
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| 233 | ; DX: Port address to Interrupt Mask Register |
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| 234 | ; Returns: |
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| 235 | ; Nothing |
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| 236 | ; Corrupts registers: |
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| 237 | ; AX |
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| 238 | ;-------------------------------------------------------------------- |
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| 239 | .ClearBitFrom8259MaskRegister: |
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| 240 | push cx |
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[592] | 241 | xchg cx, ax ; IRQ index to CL |
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| 242 | in al, dx ; Read Interrupt Mask Register |
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[589] | 243 | mov ch, ~1 ; Load bit mask to be rotated |
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| 244 | rol ch, cl ; Rotate mask to correct position for clearing |
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[33] | 245 | and al, ch ; Clear wanted bit |
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| 246 | out dx, al ; Write modified Interrupt Mask Register |
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| 247 | pop cx |
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[86] | 248 | .Return: |
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[33] | 249 | ret |
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[398] | 250 | |
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| 251 | %endif ; MODULE_IRQ |
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