| 1 | ; File name : FindDPT.asm
|
|---|
| 2 | ; Project name : IDE BIOS
|
|---|
| 3 | ; Created date : 14.3.2010
|
|---|
| 4 | ; Last update : 12.4.2010
|
|---|
| 5 | ; Author : Tomi Tilli
|
|---|
| 6 | ; Description : Functions for finding Disk Parameter Table.
|
|---|
| 7 |
|
|---|
| 8 | ; Section containing code
|
|---|
| 9 | SECTION .text
|
|---|
| 10 |
|
|---|
| 11 | ;--------------------------------------------------------------------
|
|---|
| 12 | ; Finds pointer to first unused Disk Parameter Table.
|
|---|
| 13 | ;
|
|---|
| 14 | ; FindDPT_ForNewDrive
|
|---|
| 15 | ; Parameters:
|
|---|
| 16 | ; DS: RAMVARS segment
|
|---|
| 17 | ; Returns:
|
|---|
| 18 | ; DS:DI: Ptr to first unused DPT
|
|---|
| 19 | ; Corrupts registers:
|
|---|
| 20 | ; Nothing
|
|---|
| 21 | ;--------------------------------------------------------------------
|
|---|
| 22 | ALIGN JUMP_ALIGN
|
|---|
| 23 | FindDPT_ForNewDrive:
|
|---|
| 24 | push si
|
|---|
| 25 | mov si, FindDPT_ReturnWrongDPT
|
|---|
| 26 | jmp SHORT FindDPT_StartIterationAndReturnAfterDone
|
|---|
| 27 |
|
|---|
| 28 |
|
|---|
| 29 | ;--------------------------------------------------------------------
|
|---|
| 30 | ; Finds Disk Parameter Table for
|
|---|
| 31 | ; Master or Slave drive at wanted port.
|
|---|
| 32 | ;
|
|---|
| 33 | ; FindDPT_ForIdeSlaveAtPort
|
|---|
| 34 | ; FindDPT_ForIdeMasterAtPort
|
|---|
| 35 | ; Parameters:
|
|---|
| 36 | ; DX: IDE Base Port address
|
|---|
| 37 | ; DS: RAMVARS segment
|
|---|
| 38 | ; Returns:
|
|---|
| 39 | ; DL: Drive number (if DPT found)
|
|---|
| 40 | ; DS:DI: Ptr to DPT
|
|---|
| 41 | ; CF: Set if wanted DPT found
|
|---|
| 42 | ; Cleared if DPT not found
|
|---|
| 43 | ; Corrupts registers:
|
|---|
| 44 | ; Nothing
|
|---|
| 45 | ;--------------------------------------------------------------------
|
|---|
| 46 | ALIGN JUMP_ALIGN
|
|---|
| 47 | FindDPT_ForIdeSlaveAtPort:
|
|---|
| 48 | push si
|
|---|
| 49 | mov si, FindDPT_IterateToSlaveAtPortCallback
|
|---|
| 50 | jmp SHORT FindDPT_StartIterationAndReturnAfterDone
|
|---|
| 51 |
|
|---|
| 52 | ALIGN JUMP_ALIGN
|
|---|
| 53 | FindDPT_ForIdeMasterAtPort:
|
|---|
| 54 | push si
|
|---|
| 55 | mov si, FindDPT_IterateToMasterAtPortCallback
|
|---|
| 56 | jmp SHORT FindDPT_StartIterationAndReturnAfterDone
|
|---|
| 57 |
|
|---|
| 58 | ;--------------------------------------------------------------------
|
|---|
| 59 | ; Iteration callback for finding DPT using
|
|---|
| 60 | ; IDE base port for Master or Slave drive.
|
|---|
| 61 | ;
|
|---|
| 62 | ; FindDPT_IterateToSlaveAtPortCallback
|
|---|
| 63 | ; FindDPT_IterateToMasterAtPortCallback
|
|---|
| 64 | ; Parameters:
|
|---|
| 65 | ; DX: IDE Base Port address
|
|---|
| 66 | ; DS:DI: Ptr to DPT to examine
|
|---|
| 67 | ; Returns:
|
|---|
| 68 | ; DL: Drive number if correct DPT
|
|---|
| 69 | ; CF: Set if wanted DPT found
|
|---|
| 70 | ; Cleared if wrong DPT
|
|---|
| 71 | ; Corrupts registers:
|
|---|
| 72 | ; Nothing
|
|---|
| 73 | ;--------------------------------------------------------------------
|
|---|
| 74 | ALIGN JUMP_ALIGN
|
|---|
| 75 | FindDPT_IterateToSlaveAtPortCallback:
|
|---|
| 76 | test BYTE [di+DPT.bDrvSel], FLG_IDE_DRVHD_DRV
|
|---|
| 77 | jnz SHORT FindDPT_IterateToMasterOrSlaveAtPortCallback
|
|---|
| 78 | jmp SHORT FindDPT_ReturnWrongDPT ; Return if master drive
|
|---|
| 79 |
|
|---|
| 80 | ALIGN JUMP_ALIGN
|
|---|
| 81 | FindDPT_IterateToMasterAtPortCallback:
|
|---|
| 82 | test BYTE [di+DPT.bDrvSel], FLG_IDE_DRVHD_DRV
|
|---|
| 83 | jnz SHORT FindDPT_ReturnWrongDPT ; Return if slave drive
|
|---|
| 84 |
|
|---|
| 85 | ; If BIOS partitioned, ignore all but first partition
|
|---|
| 86 | ALIGN JUMP_ALIGN
|
|---|
| 87 | FindDPT_IterateToMasterOrSlaveAtPortCallback:
|
|---|
| 88 | test BYTE [di+DPT.bFlags], FLG_DPT_PARTITION
|
|---|
| 89 | jz SHORT .CompareBasePortAddress
|
|---|
| 90 | test BYTE [di+DPT.bFlags], FLG_DPT_FIRSTPART
|
|---|
| 91 | jz SHORT FindDPT_ReturnWrongDPT
|
|---|
| 92 | ALIGN JUMP_ALIGN
|
|---|
| 93 | .CompareBasePortAddress:
|
|---|
| 94 | push bx
|
|---|
| 95 | eMOVZX bx, BYTE [di+DPT.bIdeOff] ; CS:BX now points to IDEVARS
|
|---|
| 96 | cmp dx, [cs:bx+IDEVARS.wPort] ; Wanted port?
|
|---|
| 97 | pop bx
|
|---|
| 98 | jne SHORT FindDPT_ReturnWrongDPT
|
|---|
| 99 | mov dl, [di+DPT.bDrvNum] ; Load drive number
|
|---|
| 100 | stc ; Set CF since wanted DPT
|
|---|
| 101 | ret
|
|---|
| 102 |
|
|---|
| 103 |
|
|---|
| 104 | ;--------------------------------------------------------------------
|
|---|
| 105 | ; Finds Disk Parameter Table for drive number.
|
|---|
| 106 | ; IDE Base Port address will be stored to RAMVARS if correct DPT is found.
|
|---|
| 107 | ;
|
|---|
| 108 | ; FindDPT_ForDriveNumber
|
|---|
| 109 | ; Parameters:
|
|---|
| 110 | ; DL: Drive number
|
|---|
| 111 | ; DS: RAMVARS segment
|
|---|
| 112 | ; Returns:
|
|---|
| 113 | ; DS:DI: Ptr to DPT
|
|---|
| 114 | ; CF: Set if wanted DPT found
|
|---|
| 115 | ; Cleared if DPT not found
|
|---|
| 116 | ; Corrupts registers:
|
|---|
| 117 | ; Nothing
|
|---|
| 118 | ;--------------------------------------------------------------------
|
|---|
| 119 | ALIGN JUMP_ALIGN
|
|---|
| 120 | FindDPT_ForDriveNumber:
|
|---|
| 121 | push si
|
|---|
| 122 | mov si, FindDPT_IterateToDriveNumberCallback
|
|---|
| 123 | FindDPT_StartIterationAndReturnAfterDone:
|
|---|
| 124 | call FindDPT_IterateAllDPTs
|
|---|
| 125 | pop si
|
|---|
| 126 | ret
|
|---|
| 127 |
|
|---|
| 128 | ;--------------------------------------------------------------------
|
|---|
| 129 | ; Iteration callback for finding DPT for drive number.
|
|---|
| 130 | ;
|
|---|
| 131 | ; FindDPT_IterateToDriveNumberCallback
|
|---|
| 132 | ; Parameters:
|
|---|
| 133 | ; DL: Drive number to search for
|
|---|
| 134 | ; DS:DI: Ptr to DPT to examine
|
|---|
| 135 | ; Returns:
|
|---|
| 136 | ; CF: Set if wanted DPT found
|
|---|
| 137 | ; Cleared if wrong DPT
|
|---|
| 138 | ; Corrupts registers:
|
|---|
| 139 | ; Nothing
|
|---|
| 140 | ;--------------------------------------------------------------------
|
|---|
| 141 | ALIGN JUMP_ALIGN
|
|---|
| 142 | FindDPT_IterateToDriveNumberCallback:
|
|---|
| 143 | cmp dl, [di+DPT.bDrvNum] ; Wanted DPT found?
|
|---|
| 144 | je SHORT FindDPT_RightDriveNumber ; If so, return
|
|---|
| 145 | FindDPT_ReturnWrongDPT:
|
|---|
| 146 | clc ; Clear CF since wrong DPT
|
|---|
| 147 | ret
|
|---|
| 148 | ALIGN JUMP_ALIGN
|
|---|
| 149 | FindDPT_RightDriveNumber:
|
|---|
| 150 | push bx
|
|---|
| 151 | eMOVZX bx, BYTE [di+DPT.bIdeOff] ; CS:BX now points to IDEVARS
|
|---|
| 152 | mov bx, [cs:bx+IDEVARS.wPort] ; Load IDE Base Port address...
|
|---|
| 153 | mov [RAMVARS.wIdeBase], bx ; ...and store it to RAMVARS
|
|---|
| 154 | pop bx
|
|---|
| 155 | stc
|
|---|
| 156 | ret
|
|---|
| 157 |
|
|---|
| 158 |
|
|---|
| 159 | ;--------------------------------------------------------------------
|
|---|
| 160 | ; Iterates all Disk Parameter Tables.
|
|---|
| 161 | ;
|
|---|
| 162 | ; FindDPT_IterateAllDPTs
|
|---|
| 163 | ; Parameters:
|
|---|
| 164 | ; BX,DX: Parameters to callback function
|
|---|
| 165 | ; CS:SI: Ptr to callback function
|
|---|
| 166 | ; DS: RAMVARS segment
|
|---|
| 167 | ; Returns:
|
|---|
| 168 | ; DS:DI: Ptr to wanted DPT (if found)
|
|---|
| 169 | ; CF: Set if wanted DPT found
|
|---|
| 170 | ; Cleared if DPT not found
|
|---|
| 171 | ; Corrupts registers:
|
|---|
| 172 | ; Nothing, unless corrupted by callback function
|
|---|
| 173 | ;--------------------------------------------------------------------
|
|---|
| 174 | ALIGN JUMP_ALIGN
|
|---|
| 175 | FindDPT_IterateAllDPTs:
|
|---|
| 176 | push ax
|
|---|
| 177 | push cx
|
|---|
| 178 | call FindDPT_PointToFirstDPT ; Point DS:DI to first DPT
|
|---|
| 179 | eMOVZX cx, BYTE [RAMVARS.bDrvCnt] ; Load number of drives
|
|---|
| 180 | xor ax, ax ; Zero AX for DPT size and clear CF
|
|---|
| 181 | jcxz .Return ; Return if no drives
|
|---|
| 182 | ALIGN JUMP_ALIGN
|
|---|
| 183 | .LoopWhileDPTsLeft:
|
|---|
| 184 | call si ; Is wanted DPT?
|
|---|
| 185 | jc SHORT .Return ; If so, return
|
|---|
| 186 | mov al, [di+DPT.bSize] ; Load DPT size to AX
|
|---|
| 187 | add di, ax ; Point to next DPT
|
|---|
| 188 | loop .LoopWhileDPTsLeft ; Check next DPT
|
|---|
| 189 | clc ; Clear CF since DPT not found
|
|---|
| 190 | ALIGN JUMP_ALIGN
|
|---|
| 191 | .Return:
|
|---|
| 192 | pop cx
|
|---|
| 193 | pop ax
|
|---|
| 194 | ret
|
|---|
| 195 |
|
|---|
| 196 |
|
|---|
| 197 | ;--------------------------------------------------------------------
|
|---|
| 198 | ; Sets DI to point to first Disk Parameter Table.
|
|---|
| 199 | ;
|
|---|
| 200 | ; FindDPT_PointToFirstDPT
|
|---|
| 201 | ; Parameters:
|
|---|
| 202 | ; Nothing
|
|---|
| 203 | ; Returns:
|
|---|
| 204 | ; DI: Offset to first DPT (even if unused)
|
|---|
| 205 | ; Corrupts registers:
|
|---|
| 206 | ; Nothing
|
|---|
| 207 | ;--------------------------------------------------------------------
|
|---|
| 208 | ALIGN JUMP_ALIGN
|
|---|
| 209 | FindDPT_PointToFirstDPT:
|
|---|
| 210 | mov di, RAMVARS_size
|
|---|
| 211 | test BYTE [cs:ROMVARS.wFlags], FLG_ROMVARS_FULLMODE
|
|---|
| 212 | jz SHORT .Return ; RAMVARS used (top of interrupt vectors)
|
|---|
| 213 | add di, BYTE FULLRAMVARS_size-RAMVARS_size ; FULLRAMVARS used (top of base memory)
|
|---|
| 214 | ALIGN JUMP_ALIGN
|
|---|
| 215 | .Return:
|
|---|
| 216 | ret
|
|---|
