| 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 | ; Corrupts registers: |
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| 19 | ; AX, BX, CX, DX, DI, SI |
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| 20 | ;-------------------------------------------------------------------- |
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| 21 | BootInfo_CreateForHardDisk: |
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| 22 | call BootInfo_ConvertDPTtoBX ; ES:BX now points to new BOOTNFO |
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| 23 | push bx ; Preserve for return |
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| 24 | |
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| 25 | mov di, bx ; Starting pointer at beginning of structure |
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| 26 | |
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| 27 | ; |
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| 28 | ; Store Drive Name |
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| 29 | ; |
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| 30 | push ds ; Preserve RAMVARS |
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| 31 | push si ; Preserve SI for call to GetTotalSectorCount... |
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| 32 | |
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| 33 | push es ; ES copied to DS |
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| 34 | pop ds |
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| 35 | |
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| 36 | add si, BYTE ATA1.strModel ; DS:SI now points drive name |
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| 37 | lea di, [bx+BOOTNFO.szDrvName] ; ES:DI now points to name destination |
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| 38 | mov cx, LEN_BOOTNFO_DRV / 2 ; Max number of WORDs allowed |
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| 39 | .CopyNextWord: |
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| 40 | lodsw |
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| 41 | xchg al, ah ; Change endianness |
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| 42 | stosw |
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| 43 | loop .CopyNextWord |
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| 44 | xor ax, ax ; Zero AX and clear CF |
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| 45 | stosw ; Terminate with NULL |
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| 46 | |
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| 47 | pop si |
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| 48 | pop ds |
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| 49 | pop bx |
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| 50 | |
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| 51 | ret |
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| 52 | |
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| 53 | |
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| 54 | ;-------------------------------------------------------------------- |
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| 55 | ; BootInfo_GetTotalSectorCount |
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| 56 | ; Parameters: |
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| 57 | ; DS:DI: DPT Pointer |
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| 58 | ; Returns: |
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| 59 | ; BX:DX:AX: 48-bit sector count |
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| 60 | ; Corrupts registers: |
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| 61 | ; CX |
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| 62 | ;-------------------------------------------------------------------- |
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| 63 | ALIGN JUMP_ALIGN |
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| 64 | BootInfo_GetTotalSectorCount: |
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| 65 | test BYTE [di+DPT.bFlagsLow], FLG_DRVNHEAD_LBA |
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| 66 | jnz SHORT .ReturnFullCapacity |
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| 67 | jmp AH15h_GetSectorCountToBXDXAX |
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| 68 | .ReturnFullCapacity: |
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| 69 | jmp AccessDPT_GetLbaSectorCountToBXDXAX |
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| 70 | |
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| 71 | |
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| 72 | ;-------------------------------------------------------------------- |
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| 73 | ; Returns offset to BOOTNFO based on DPT pointer. |
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| 74 | ; |
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| 75 | ; BootInfo_ConvertDPTtoBX |
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| 76 | ; Parameters: |
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| 77 | ; DS:DI: DPT Pointer |
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| 78 | ; Returns: |
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| 79 | ; BX: Offset to BOOTNFO struct |
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| 80 | ; Corrupts registers: |
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| 81 | ; AX |
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| 82 | ;-------------------------------------------------------------------- |
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| 83 | ALIGN JUMP_ALIGN |
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| 84 | BootInfo_ConvertDPTtoBX: |
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| 85 | mov ax, di |
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| 86 | sub ax, RAMVARS_size ; subtract off base of DPTs |
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| 87 | mov bl, DPT_BOOTNFO_SIZE_MULTIPLIER ; BOOTNFO's are a whole number multiple of DPT size |
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| 88 | mul bl |
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| 89 | add ax, BOOTVARS.rgBootNfo ; add base of BOOTNFO |
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| 90 | xchg ax, bx |
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| 91 | ret |
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