| 1 | ; Project name : XTIDE Universal BIOS |
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| 2 | ; Description : Defines for DPT structs containing custom |
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| 3 | ; Disk Parameter Table used by this BIOS. |
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| 4 | %ifndef CUSTOMDPT_INC |
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| 5 | %define CUSTOMDPT_INC |
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| 6 | |
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| 7 | ; Base DPT for all device types |
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| 8 | struc DPT ; 10 bytes |
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| 9 | ; General Disk Parameter Table related |
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| 10 | .wFlags: |
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| 11 | .bFlagsLow resb 1 |
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| 12 | .bFlagsHigh resb 1 |
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| 13 | .bIdevarsOffset resb 1 ; Offset to IDEVARS for this drive |
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| 14 | resb 1 |
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| 15 | |
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| 16 | ; IDE Drive related |
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| 17 | .dwCylinders resb 4 ; Number of Cylinders |
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| 18 | .wHeadsAndSectors: |
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| 19 | .bHeads resb 1 ; Number of Heads (1...255) |
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| 20 | .bSectors resb 1 ; Number of Sectors per Track (1...63) |
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| 21 | endstruc |
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| 22 | |
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| 23 | ; DPT for ATA devices |
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| 24 | struc DPT_ATA ; 10 + 2 bytes = 12 bytes |
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| 25 | .dpt resb DPT_size |
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| 26 | |
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| 27 | ; Block size is specified in sectors (1, 2, 4, 8, 16, 32 or 64). |
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| 28 | ; 128 is not allowed to prevent offset overflow during data transfer. |
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| 29 | .wSetAndMaxBlock: |
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| 30 | .bSetBlock resb 1 ; Current block size (at least 1) |
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| 31 | .bMaxBlock resb 1 ; Maximum block size, 0 = block mode not supported |
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| 32 | endstruc |
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| 33 | |
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| 34 | LARGEST_DPT_SIZE EQU DPT_ATA_size |
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| 35 | |
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| 36 | |
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| 37 | ; Bit definitions for DPT.bFlagsLow |
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| 38 | MASKL_DPT_CHS_SHIFT_COUNT EQU (7<<0) ; Bits 0...3, P-CHS to L-CHS bit shift count (0...4) |
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| 39 | FLGL_DPT_SLAVE EQU FLG_DRVNHEAD_DRV ; (1<<4), Drive is slave drive |
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| 40 | MASKL_DPT_ADDRESSING_MODE EQU (3<<5) ; Bits 5..6, Addressing Mode (bit 6 == FLG_DRVNHEAD_LBA) |
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| 41 | FLGL_DPT_ENABLE_IRQ EQU (1<<7) |
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| 42 | |
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| 43 | ; Bit definitions for DPT.bFlagsHigh |
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| 44 | FLGH_DPT_REVERSED_A0_AND_A3 EQU (1<<0) ; XTIDE mod, Address lines 0 and 3 reversed |
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| 45 | FLGH_DPT_BLOCK_MODE_SUPPORTED EQU (1<<1) ; Use block transfer commands (must be bit 1!) |
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| 46 | FLGH_DPT_SERIAL_DEVICE EQU (1<<2) ; Serial Port Device |
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| 47 | FLGH_DPT_INTERRUPT_IN_SERVICE EQU (1<<3) ; Set when waiting for IRQ |
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| 48 | FLGH_DPT_RESET_nDRDY EQU (1<<4) ; Drive ready to accept commands |
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| 49 | FLGH_DPT_RESET_nINITPRMS EQU (1<<5) ; Initialize Device Parameters successfull |
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| 50 | FLGH_DPT_RESET_nRECALIBRATE EQU (1<<6) ; Recalibrate successfull |
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| 51 | FLGH_DPT_RESET_nSETBLOCK EQU (1<<7) ; Initialize Block Mode successfull |
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| 52 | MASKH_DPT_RESET EQU 0F0h |
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| 53 | |
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| 54 | ; Addressing modes for DPT.wFlags |
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| 55 | ADDRESSING_MODE_FIELD_POSITION EQU 5 |
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| 56 | ADDRESSING_MODE_LCHS EQU 0 ; L-CHS Addressing Mode (NORMAL in many other BIOSes) |
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| 57 | ADDRESSING_MODE_PCHS EQU 1 ; P-CHS Addressing Mode (LARGE in many other BIOSes) |
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| 58 | ADDRESSING_MODE_LBA28 EQU 2 ; 28-bit LBA Addressing Mode |
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| 59 | ADDRESSING_MODE_LBA48 EQU 3 ; 48-bit LBA Addressing Mode |
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| 60 | |
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| 61 | ; Number of Sectors per Track is fixed to 63 for LBA assist calculation. |
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| 62 | ; 1024 cylinders, 256 heads, 63 sectors = 8.4 GB limit (but DOS does not support more than 255 heads) |
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| 63 | MAX_LCHS_CYLINDERS EQU 1024 |
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| 64 | LBA_ASSIST_SPT EQU 63 |
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| 65 | |
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| 66 | |
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| 67 | %endif ; CUSTOMDPT_INC |
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