| [90] | 1 | ; Project name : XTIDE Universal BIOS |
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| [3] | 2 | ; Description : Int 19h BIOS functions for Boot Menu. |
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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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| [122] | 8 | ; Boot Menu Loader. |
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| [3] | 9 | ; |
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| 10 | ; Int19hMenu_BootLoader |
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| 11 | ; Parameters: |
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| 12 | ; Nothing |
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| 13 | ; Returns: |
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| 14 | ; Jumps to Int19hMenu_Display, then never returns |
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| 15 | ;-------------------------------------------------------------------- |
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| 16 | ALIGN JUMP_ALIGN |
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| 17 | Int19hMenu_BootLoader: |
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| [121] | 18 | ; Store POST stack pointer |
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| [3] | 19 | LOAD_BDA_SEGMENT_TO ds, ax |
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| [121] | 20 | STORE_POST_STACK_POINTER |
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| 21 | SWITCH_TO_BOOT_MENU_STACK |
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| 22 | CALL_DISPLAY_LIBRARY InitializeDisplayContext |
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| [3] | 23 | call RamVars_GetSegmentToDS |
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| [96] | 24 | ; Fall to .ProcessMenuSelectionsUntilBootable |
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| [3] | 25 | |
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| 26 | ;-------------------------------------------------------------------- |
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| [96] | 27 | ; .ProcessMenuSelectionsUntilBootable |
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| [3] | 28 | ; Parameters: |
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| 29 | ; DS: RAMVARS segment |
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| 30 | ; Returns: |
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| 31 | ; Never returns |
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| 32 | ;-------------------------------------------------------------------- |
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| 33 | ALIGN JUMP_ALIGN |
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| [96] | 34 | .ProcessMenuSelectionsUntilBootable: |
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| [95] | 35 | call BootMenu_DisplayAndReturnSelection |
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| 36 | call DriveXlate_ToOrBack ; Translate drive number |
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| [96] | 37 | call BootSector_TryToLoadFromDriveDL |
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| 38 | jnc SHORT .ProcessMenuSelectionsUntilBootable ; Boot failure, show menu again |
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| [121] | 39 | SWITCH_BACK_TO_POST_STACK |
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| [96] | 40 | ; Fall to JumpToBootSector |
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| [3] | 41 | |
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| [96] | 42 | ;-------------------------------------------------------------------- |
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| 43 | ; JumpToBootSector |
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| 44 | ; Parameters: |
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| 45 | ; DL: Drive to boot from (translated, 00h or 80h) |
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| 46 | ; ES:BX: Ptr to boot sector |
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| 47 | ; Returns: |
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| 48 | ; Never returns |
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| 49 | ;-------------------------------------------------------------------- |
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| 50 | ALIGN JUMP_ALIGN |
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| 51 | JumpToBootSector: |
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| 52 | push es ; Push boot sector segment |
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| 53 | push bx ; Push boot sector offset |
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| 54 | call ClearSegmentsForBoot |
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| 55 | retf |
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| [3] | 56 | |
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| [96] | 57 | |
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| [3] | 58 | ;-------------------------------------------------------------------- |
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| [95] | 59 | ; Int19hMenu_RomBoot |
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| [3] | 60 | ; Parameters: |
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| 61 | ; DS: RAMVARS segment |
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| 62 | ; Returns: |
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| [95] | 63 | ; Never returns |
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| [3] | 64 | ;-------------------------------------------------------------------- |
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| 65 | ALIGN JUMP_ALIGN |
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| [95] | 66 | Int19hMenu_RomBoot: |
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| [121] | 67 | SWITCH_BACK_TO_POST_STACK |
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| [96] | 68 | call ClearSegmentsForBoot |
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| [95] | 69 | int INTV_BOOT_FAILURE ; Never returns |
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| [96] | 70 | |
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| 71 | |
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| 72 | ;-------------------------------------------------------------------- |
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| 73 | ; ClearSegmentsForBoot |
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| 74 | ; Parameters: |
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| 75 | ; Nothing |
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| 76 | ; Returns: |
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| [121] | 77 | ; DX: Zero |
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| [96] | 78 | ; DS=ES: Zero |
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| 79 | ; Corrupts registers: |
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| [121] | 80 | ; Nothing |
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| [96] | 81 | ;-------------------------------------------------------------------- |
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| 82 | ALIGN JUMP_ALIGN |
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| 83 | ClearSegmentsForBoot: |
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| [121] | 84 | xor dx, dx ; Device supported by INT 13h |
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| 85 | mov ds, dx |
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| 86 | mov es, dx |
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| [96] | 87 | ret |
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