| 1 | ; Project name : XTIDE Universal BIOS |
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| 2 | ; Description : Functions for loading correct transfer command. |
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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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| 8 | ; CommandLookup_GetEbiosIndexToBX |
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| 9 | ; Parameters: |
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| 10 | ; DS:DI: Ptr to DPT |
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| 11 | ; ES:SI: Ptr to DAP (Disk Address Packet) |
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| 12 | ; Returns: |
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| 13 | ; BX: Index to command lookup table |
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| 14 | ; Corrupts registers: |
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| 15 | ; AX, DX |
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| 16 | ;-------------------------------------------------------------------- |
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| 17 | ALIGN JUMP_ALIGN |
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| 18 | CommandLookup_GetEbiosIndexToBX: |
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| 19 | ; LBA28 or LBA48 command |
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| 20 | xor dx, dx |
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| 21 | mov al, [es:si+DAP.qwLBA+3] ; Load LBA48 byte 3 (bits 24...31) |
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| 22 | and ax, 00F0h ; Clear LBA28 bits 24...27 |
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| 23 | or ax, [es:si+DAP.qwLBA+4] ; Set bits from LBA bytes 4 and 5 |
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| 24 | cmp dx, ax ; Set CF if any of bits 28...47 set |
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| 25 | rcl dx, 1 ; DX = 0 for LBA28, DX = 1 for LBA48 |
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| 26 | call CommandLookup_GetOldInt13hIndexToBX |
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| 27 | or bx, dx ; Set block mode / single sector bit |
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| 28 | ret |
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| 29 | |
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| 30 | ;-------------------------------------------------------------------- |
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| 31 | ; CommandLookup_GetOldInt13hIndexToBX |
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| 32 | ; Parameters: |
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| 33 | ; DS:DI: Ptr to DPT |
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| 34 | ; Returns: |
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| 35 | ; BX: Index to command lookup table |
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| 36 | ; Corrupts registers: |
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| 37 | ; Nothing |
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| 38 | ;-------------------------------------------------------------------- |
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| 39 | ALIGN JUMP_ALIGN |
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| 40 | CommandLookup_GetOldInt13hIndexToBX: |
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| 41 | ; Block mode or single sector |
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| 42 | mov bl, [di+DPT.bFlagsHigh] |
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| 43 | and bx, BYTE FLGH_DPT_BLOCK_MODE_SUPPORTED ; Bit 1 |
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| 44 | ret |
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| 45 | |
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| 46 | |
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| 47 | g_rgbReadCommandLookup: |
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| 48 | db COMMAND_READ_SECTORS ; 00b, CHS or LBA28 single sector |
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| 49 | db COMMAND_READ_SECTORS_EXT ; 01b, LBA48 single sector |
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| 50 | db COMMAND_READ_MULTIPLE ; 10b, CHS or LBA28 block mode |
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| 51 | db COMMAND_READ_MULTIPLE_EXT ; 11b, LBA48 block mode |
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| 52 | |
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| 53 | g_rgbWriteCommandLookup: |
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| 54 | db COMMAND_WRITE_SECTORS |
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| 55 | db COMMAND_WRITE_SECTORS_EXT |
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| 56 | db COMMAND_WRITE_MULTIPLE |
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| 57 | db COMMAND_WRITE_MULTIPLE_EXT |
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| 58 | |
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| 59 | g_rgbVerifyCommandLookup: |
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| 60 | db COMMAND_VERIFY_SECTORS |
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| 61 | db COMMAND_VERIFY_SECTORS_EXT |
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| 62 | db COMMAND_VERIFY_SECTORS |
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| 63 | db COMMAND_VERIFY_SECTORS_EXT |
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