| 1 | ; Project name : XTIDE Universal BIOS
|
|---|
| 2 | ; Description : Functions for finding Disk Parameter Table.
|
|---|
| 3 |
|
|---|
| 4 | ; Section containing code
|
|---|
| 5 | SECTION .text
|
|---|
| 6 |
|
|---|
| 7 | ;--------------------------------------------------------------------
|
|---|
| 8 | ; Finds pointer to first unused Disk Parameter Table.
|
|---|
| 9 | ;
|
|---|
| 10 | ; FindDPT_ForNewDriveToDSDI
|
|---|
| 11 | ; Parameters:
|
|---|
| 12 | ; DS: RAMVARS segment
|
|---|
| 13 | ; Returns:
|
|---|
| 14 | ; DS:DI: Ptr to first unused DPT
|
|---|
| 15 | ; Corrupts registers:
|
|---|
| 16 | ; DL
|
|---|
| 17 | ;--------------------------------------------------------------------
|
|---|
| 18 | ALIGN JUMP_ALIGN
|
|---|
| 19 | FindDPT_ForNewDriveToDSDI:
|
|---|
| 20 | mov dl, [RAMVARS.bFirstDrv]
|
|---|
| 21 | add dl, [RAMVARS.bDrvCnt]
|
|---|
| 22 | ; Fall to FindDPT_ForDriveNumber
|
|---|
| 23 |
|
|---|
| 24 |
|
|---|
| 25 | ;--------------------------------------------------------------------
|
|---|
| 26 | ; Finds Disk Parameter Table for drive number.
|
|---|
| 27 | ; IDE Base Port address will be stored to RAMVARS if correct DPT is found.
|
|---|
| 28 | ;
|
|---|
| 29 | ; FindDPT_ForDriveNumber
|
|---|
| 30 | ; Parameters:
|
|---|
| 31 | ; DL: Drive number
|
|---|
| 32 | ; DS: RAMVARS segment
|
|---|
| 33 | ; Returns:
|
|---|
| 34 | ; DS:DI: Ptr to DPT
|
|---|
| 35 | ; Corrupts registers:
|
|---|
| 36 | ; Nothing
|
|---|
| 37 | ;--------------------------------------------------------------------
|
|---|
| 38 | ALIGN JUMP_ALIGN
|
|---|
| 39 | FindDPT_ForDriveNumber:
|
|---|
| 40 | push dx
|
|---|
| 41 | xchg di, ax ; Save the contents of AX in DI
|
|---|
| 42 |
|
|---|
| 43 | mov al, LARGEST_DPT_SIZE
|
|---|
| 44 | sub dl, [RAMVARS.bFirstDrv]
|
|---|
| 45 | mul dl
|
|---|
| 46 | add ax, BYTE RAMVARS_size
|
|---|
| 47 |
|
|---|
| 48 | xchg di, ax ; Restore AX and put result in DI
|
|---|
| 49 | pop dx
|
|---|
| 50 | ret
|
|---|
| 51 |
|
|---|
| 52 |
|
|---|
| 53 | ;--------------------------------------------------------------------
|
|---|
| 54 | ; Finds Disk Parameter Table for
|
|---|
| 55 | ; Master or Slave drive at wanted port.
|
|---|
| 56 | ;
|
|---|
| 57 | ; FindDPT_ToDSDIForIdeMasterAtPortDX
|
|---|
| 58 | ; FindDPT_ToDSDIForIdeSlaveAtPortDX
|
|---|
| 59 | ; Parameters:
|
|---|
| 60 | ; DX: IDE Base Port address
|
|---|
| 61 | ; DS: RAMVARS segment
|
|---|
| 62 | ; Returns:
|
|---|
| 63 | ; DL: Drive number (if DPT found)
|
|---|
| 64 | ; DS:DI: Ptr to DPT
|
|---|
| 65 | ; CF: Set if wanted DPT found
|
|---|
| 66 | ; Cleared if DPT not found
|
|---|
| 67 | ; Corrupts registers:
|
|---|
| 68 | ; SI
|
|---|
| 69 | ;--------------------------------------------------------------------
|
|---|
| 70 | ALIGN JUMP_ALIGN
|
|---|
| 71 | FindDPT_ToDSDIForIdeMasterAtPortDX:
|
|---|
| 72 | mov si, IterateToMasterAtPortCallback
|
|---|
| 73 | jmp SHORT IterateAllDPTs
|
|---|
| 74 |
|
|---|
| 75 | ALIGN JUMP_ALIGN
|
|---|
| 76 | FindDPT_ToDSDIForIdeSlaveAtPortDX:
|
|---|
| 77 | mov si, IterateToSlaveAtPortCallback
|
|---|
| 78 | jmp SHORT IterateAllDPTs
|
|---|
| 79 |
|
|---|
| 80 | ;--------------------------------------------------------------------
|
|---|
| 81 | ; Iteration callback for finding DPT using
|
|---|
| 82 | ; IDE base port for Master or Slave drive.
|
|---|
| 83 | ;
|
|---|
| 84 | ; IterateToSlaveAtPortCallback
|
|---|
| 85 | ; IterateToMasterAtPortCallback
|
|---|
| 86 | ; Parameters:
|
|---|
| 87 | ; CH: Drive number
|
|---|
| 88 | ; DX: IDE Base Port address
|
|---|
| 89 | ; DS:DI: Ptr to DPT to examine
|
|---|
| 90 | ; Returns:
|
|---|
| 91 | ; DL: Drive number if correct DPT
|
|---|
| 92 | ; CF: Set if wanted DPT found
|
|---|
| 93 | ; Cleared if wrong DPT
|
|---|
| 94 | ; Corrupts registers:
|
|---|
| 95 | ; Nothing
|
|---|
| 96 | ;--------------------------------------------------------------------
|
|---|
| 97 | ALIGN JUMP_ALIGN
|
|---|
| 98 | IterateToSlaveAtPortCallback:
|
|---|
| 99 | test BYTE [di+DPT.bFlagsLow], FLGL_DPT_SLAVE ; Clears CF
|
|---|
| 100 | jnz SHORT CompareBasePortAddress
|
|---|
| 101 | ret ; Wrong DPT
|
|---|
| 102 |
|
|---|
| 103 | ALIGN JUMP_ALIGN
|
|---|
| 104 | IterateToMasterAtPortCallback:
|
|---|
| 105 | test BYTE [di+DPT.bFlagsLow], FLGL_DPT_SLAVE
|
|---|
| 106 | jnz SHORT ReturnWrongDPT ; Return if slave drive
|
|---|
| 107 |
|
|---|
| 108 | CompareBasePortAddress:
|
|---|
| 109 | push bx
|
|---|
| 110 | eMOVZX bx, BYTE [di+DPT.bIdevarsOffset] ; CS:BX now points to IDEVARS
|
|---|
| 111 | cmp dx, [cs:bx+IDEVARS.wPort] ; Wanted port?
|
|---|
| 112 | pop bx
|
|---|
| 113 | jne SHORT ReturnWrongDPT
|
|---|
| 114 | mov dl, ch ; Return drive number in DL
|
|---|
| 115 | stc ; Set CF since wanted DPT
|
|---|
| 116 | ret
|
|---|
| 117 |
|
|---|
| 118 |
|
|---|
| 119 | ;--------------------------------------------------------------------
|
|---|
| 120 | ; IterateToDptWithInterruptInServiceFlagSet
|
|---|
| 121 | ; Parameters:
|
|---|
| 122 | ; DS:DI: Ptr to DPT to examine
|
|---|
| 123 | ; Returns:
|
|---|
| 124 | ; CF: Set if wanted DPT found
|
|---|
| 125 | ; Cleared if wrong DPT
|
|---|
| 126 | ; Corrupts registers:
|
|---|
| 127 | ; Nothing
|
|---|
| 128 | ;--------------------------------------------------------------------
|
|---|
| 129 | ALIGN JUMP_ALIGN
|
|---|
| 130 | IterateToDptWithInterruptInServiceFlagSet:
|
|---|
| 131 | test BYTE [di+DPT.bFlagsHigh], FLGH_DPT_INTERRUPT_IN_SERVICE
|
|---|
| 132 | jz SHORT ReturnWrongDPT
|
|---|
| 133 | stc ; Set CF since wanted DPT
|
|---|
| 134 | ret
|
|---|
| 135 | ReturnWrongDPT:
|
|---|
| 136 | clc ; Clear CF since wrong DPT
|
|---|
| 137 | ret
|
|---|
| 138 |
|
|---|
| 139 |
|
|---|
| 140 | ;--------------------------------------------------------------------
|
|---|
| 141 | ; FindDPT_ToDSDIforInterruptInService
|
|---|
| 142 | ; Parameters:
|
|---|
| 143 | ; DS: RAMVARS segment
|
|---|
| 144 | ; Returns:
|
|---|
| 145 | ; DS:DI: Ptr to DPT
|
|---|
| 146 | ; CF: Set if wanted DPT found
|
|---|
| 147 | ; Cleared if DPT not found
|
|---|
| 148 | ; Corrupts registers:
|
|---|
| 149 | ; SI
|
|---|
| 150 | ;--------------------------------------------------------------------
|
|---|
| 151 | ALIGN JUMP_ALIGN
|
|---|
| 152 | FindDPT_ToDSDIforInterruptInService:
|
|---|
| 153 | mov si, IterateToDptWithInterruptInServiceFlagSet
|
|---|
| 154 | ; Fall to IterateAllDPTs
|
|---|
| 155 |
|
|---|
| 156 |
|
|---|
| 157 | ;--------------------------------------------------------------------
|
|---|
| 158 | ; Iterates all Disk Parameter Tables.
|
|---|
| 159 | ;
|
|---|
| 160 | ; IterateAllDPTs
|
|---|
| 161 | ; Parameters:
|
|---|
| 162 | ; AX,BX,DX: Parameters to callback function
|
|---|
| 163 | ; CS:SI: Ptr to callback function
|
|---|
| 164 | ; DS: RAMVARS segment
|
|---|
| 165 | ; Returns:
|
|---|
| 166 | ; DS:DI: Ptr to wanted DPT (if found)
|
|---|
| 167 | ; CF: Set if wanted DPT found
|
|---|
| 168 | ; Cleared if DPT not found
|
|---|
| 169 | ; Unchanged if no drives
|
|---|
| 170 | ; Corrupts registers:
|
|---|
| 171 | ; Nothing unless corrupted by callback function
|
|---|
| 172 | ;--------------------------------------------------------------------
|
|---|
| 173 | ALIGN JUMP_ALIGN
|
|---|
| 174 | IterateAllDPTs:
|
|---|
| 175 | push cx
|
|---|
| 176 | mov cx, [RAMVARS.wDrvCntAndFirst]
|
|---|
| 177 | jcxz .AllDptsIterated ; Return if no drives
|
|---|
| 178 | mov di, RAMVARS_size ; Point DS:DI to first DPT
|
|---|
| 179 | ALIGN JUMP_ALIGN
|
|---|
| 180 | .LoopWhileDPTsLeft:
|
|---|
| 181 | call si ; Is wanted DPT?
|
|---|
| 182 | jc SHORT .AllDptsIterated ; If so, return
|
|---|
| 183 | inc ch ; Increment drive number
|
|---|
| 184 | add di, BYTE LARGEST_DPT_SIZE ; Point to next DPT
|
|---|
| 185 | dec cl ; Decrement drives left
|
|---|
| 186 | jnz SHORT .LoopWhileDPTsLeft
|
|---|
| 187 | clc ; Clear CF since DPT not found
|
|---|
| 188 | ALIGN JUMP_ALIGN
|
|---|
| 189 | .AllDptsIterated:
|
|---|
| 190 | pop cx
|
|---|
| 191 | ret
|
|---|
