| 1 | ; Project name : XTIDE Universal BIOS |
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| 2 | ; Description : Functions for generating and accessing drive |
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| 3 | ; information to be displayed on boot menu. |
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| 4 | |
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| 5 | ; Section containing code |
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| 6 | SECTION .text |
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| 7 | |
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| 8 | ;-------------------------------------------------------------------- |
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| 9 | ; Creates new BOOTNFO struct for detected hard disk. |
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| 10 | ; |
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| 11 | ; BootInfo_CreateForHardDisk |
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| 12 | ; Parameters: |
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| 13 | ; DL: Drive number |
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| 14 | ; DS:DI: Ptr to Disk Parameter Table |
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| 15 | ; ES:SI: Ptr to 512-byte ATA information read from the drive |
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| 16 | ; Returns: |
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| 17 | ; ES:BX: Ptr to BOOTNFO (if successful) |
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| 18 | ; CF: Cleared if BOOTNFO created succesfully |
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| 19 | ; Set if any error |
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| 20 | ; Corrupts registers: |
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| 21 | ; AX, BX, CX, DX |
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| 22 | ;-------------------------------------------------------------------- |
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| 23 | BootInfo_CreateForHardDisk: |
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| 24 | call BootInfo_GetOffsetToBX ; ES:BX now points to new BOOTNFO |
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| 25 | ; Fall to .StoreSectorCount |
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| 26 | |
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| 27 | ;-------------------------------------------------------------------- |
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| 28 | ; .StoreSectorCount |
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| 29 | ; Parameters: |
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| 30 | ; ES:BX: Ptr to BOOTNFO |
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| 31 | ; ES:SI: Ptr to 512-byte ATA information read from the drive |
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| 32 | ; DS:DI: Ptr to Disk Parameter Table |
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| 33 | ; Returns: |
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| 34 | ; Nothing |
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| 35 | ; Corrupts registers: |
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| 36 | ; AX, CX, DX |
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| 37 | ;-------------------------------------------------------------------- |
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| 38 | .StoreSectorCount: |
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| 39 | push bx |
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| 40 | call AtaID_GetTotalSectorCount ; Get to BX:DX:AX |
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| 41 | mov cx, bx ; Now in CX:DX:AX |
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| 42 | pop bx |
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| 43 | mov [es:bx+BOOTNFO.twSectCnt], ax |
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| 44 | mov [es:bx+BOOTNFO.twSectCnt+2], dx |
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| 45 | mov [es:bx+BOOTNFO.twSectCnt+4], cx |
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| 46 | ; Fall to .StoreDriveName |
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| 47 | |
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| 48 | ;-------------------------------------------------------------------- |
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| 49 | ; .StoreDriveName |
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| 50 | ; Parameters: |
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| 51 | ; ES:BX: Ptr to BOOTNFO |
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| 52 | ; ES:SI: Ptr to 512-byte ATA information read from the drive |
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| 53 | ; DS:DI: Ptr to Disk Parameter Table |
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| 54 | ; Returns: |
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| 55 | ; CF: Cleared if variables stored succesfully |
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| 56 | ; Set if any error |
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| 57 | ; Corrupts registers: |
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| 58 | ; AX, CX |
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| 59 | ;-------------------------------------------------------------------- |
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| 60 | .StoreDriveName: |
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| 61 | push ds |
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| 62 | push si |
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| 63 | push di |
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| 64 | |
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| 65 | push es |
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| 66 | pop ds |
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| 67 | add si, BYTE ATA1.strModel ; DS:SI now points drive name |
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| 68 | lea di, [bx+BOOTNFO.szDrvName] ; ES:DI now points to name destination |
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| 69 | mov cx, LEN_BOOTNFO_DRV / 2 ; Max number of WORDs allowed |
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| 70 | .CopyNextWord: |
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| 71 | lodsw |
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| 72 | xchg al, ah ; Change endianness |
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| 73 | stosw |
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| 74 | loop .CopyNextWord |
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| 75 | xor ax, ax ; Zero AX and clear CF |
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| 76 | stosb ; Terminate with NULL |
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| 77 | |
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| 78 | pop di |
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| 79 | pop si |
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| 80 | pop ds |
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| 81 | ret |
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| 82 | |
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| 83 | |
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| 84 | ;-------------------------------------------------------------------- |
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| 85 | ; Finds BOOTNFO for drive and returns total sector count. |
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| 86 | ; |
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| 87 | ; BootInfo_GetTotalSectorCount |
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| 88 | ; Parameters: |
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| 89 | ; DL: Drive number |
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| 90 | ; DS: RAMVARS segment |
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| 91 | ; Returns: |
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| 92 | ; BX:DX:AX: 48-bit sector count |
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| 93 | ; Corrupts registers: |
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| 94 | ; Nothing |
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| 95 | ;-------------------------------------------------------------------- |
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| 96 | ALIGN JUMP_ALIGN |
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| 97 | BootInfo_GetTotalSectorCount: |
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| 98 | push ds |
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| 99 | call BootInfo_GetOffsetToBX |
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| 100 | LOAD_BDA_SEGMENT_TO ds, ax |
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| 101 | mov ax, [bx+BOOTNFO.twSectCnt] |
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| 102 | mov dx, [bx+BOOTNFO.twSectCnt+2] |
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| 103 | mov bx, [bx+BOOTNFO.twSectCnt+4] |
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| 104 | pop ds |
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| 105 | ret |
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| 106 | |
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| 107 | |
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| 108 | ;-------------------------------------------------------------------- |
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| 109 | ; Returns offset to BOOTNFO for wanted drive. |
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| 110 | ; |
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| 111 | ; BootInfo_GetOffsetToBX |
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| 112 | ; Parameters: |
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| 113 | ; DL: Drive number |
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| 114 | ; DS: RAMVARS segment |
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| 115 | ; Returns: |
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| 116 | ; BX: Offset to BOOTNFO struct |
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| 117 | ; Corrupts registers: |
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| 118 | ; AX |
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| 119 | ;-------------------------------------------------------------------- |
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| 120 | ALIGN JUMP_ALIGN |
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| 121 | BootInfo_GetOffsetToBX: |
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| 122 | mov bl, dl ; Copy drive number to BL |
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| 123 | mov al, BOOTNFO_size ; Size of struct |
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| 124 | sub bl, [RAMVARS.bFirstDrv] ; Drive number to index |
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| 125 | mul bl ; AX = Offset inside BOOTNFO array |
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| 126 | add ax, BOOTVARS.rgBootNfo ; Add offset to BOOTNFO array |
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| 127 | xchg bx, ax ; Copy result to BX |
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| 128 | ret |
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