Changeset 421 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/Tools/Address.asm

Timestamp:

May 9, 2012, 7:12:53 PM (12 years ago)

Author:

aitotat@…

google:author:

aitotat@gmail.com

Message:

Changes to XTIDE Universal BIOS:

• Addressing modes are now NORMAL, LARGE and LBA.
• L-CHS parameters are now generated differently for drives with 8192 or less cylinders.

File:

• trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/Tools/Address.asm (modified) (8 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/Tools/Address.asm

@@ -47 +47 @@
 
 ;---------------------------------------------------------------------
-; Converts LCHS parameters to IDE P-CHS parameters.
+; Converts LARGE addressing mode LCHS parameters to IDE P-CHS parameters.
 ; PCylinder = (LCylinder << n) + (LHead / PHeadCount)
 ; PHead     = LHead % PHeadCount
 ; PSector   = LSector
 ;
-; Address_ConvertLCHStoPCHS:
+; ConvertLargeModeLCHStoPCHS:
 ;   Parameters:
 ;       BL:     Sector number (1...63)
-;       BH:     Head number (0...255)
+;       BH:     Head number (0...239)
 ;       CX:     Cylinder number (0...1023)
 ;       DS:DI:  Ptr to Disk Parameter Table
@@ -66 +66 @@
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
-ConvertLCHStoPCHS:
+ConvertLargeModeLCHStoPCHS:
     ; LHead / PHeadCount and LHead % PHeadCount
     eMOVZX  ax, bh                  ; Copy L-CHS Head number to AX
@@ -82 +82 @@
 DoNotConvertLCHS:
     ret
+
 
 ;--------------------------------------------------------------------
@@ -102 +103 @@
 Address_OldInt13hAddressToIdeAddress:
         call    Address_ExtractLCHSparametersFromOldInt13hAddress
+        ACCESSDPT__GET_UNSHIFTED_ADDRESS_MODE_TO_AXZF
 
-        AccessDPT_GetUnshiftedAddressModeToALZF
+;;; 0: ADDRESSING_MODE_NORMAL
+        jz      SHORT DoNotConvertLCHS
 
-;;; 0: ADDR_DPT_LCHS
-        jz      DoNotConvertLCHS
+;;; 1: ADDRESSING_MODE_LARGE
+        test    al, FLGL_DPT_ASSISTED_LBA
+        jz      SHORT ConvertLargeModeLCHStoPCHS
 
-;;; 1: ADDR_DPT_PCHS
-        ;
-        ; Since we are only checking for zero, we can do our math in the high order bits,
-        ; in this case effectively subtracting 1 from the address mode.
-        ;
-        sub     al,(1<<ADDRESSING_MODE_FIELD_POSITION)
-        jz      ConvertLCHStoPCHS
+;;; 2: ADDRESSING_MODE_ASSISTED_LBA
+        ; Fall through to ConvertAssistedLBAModeLCHStoLBARegisterValues
 
-;;; 2: ADDR_DPT_LBA28 and 3: ADDR_DPT_LBA48
-        ; Fall through to ConvertLCHStoLBARegisterValues
 
 ;---------------------------------------------------------------------
@@ -125 +122 @@
 ;
 ; Returned address is in same registers that
-; Address_DoNotConvertLCHS and Address_ConvertLCHStoPCHS returns.
+; DoNotConvertLCHS and ConvertLargeModeLCHStoPCHS returns.
 ;
-; ConvertLCHStoLBARegisterValues:
+; ConvertAssistedLBAModeLCHStoLBARegisterValues:
 ;   Parameters:
 ;       BL:     Sector number (1...63)
-;       BH:     Head number (0...255)
+;       BH:     Head number (0...254)
 ;       CX:     Cylinder number (0...1023)
 ;       DS:DI:  Ptr to Disk Parameter Table
@@ -141 +138 @@
 ;       AX, DX
 ;--------------------------------------------------------------------
-ALIGN JUMP_ALIGN
-ConvertLCHStoLBARegisterValues:
+ConvertAssistedLBAModeLCHStoLBARegisterValues:
     ; cylToSeek*headsPerCyl (18-bit result)
+    ; Max = 1023 * 255 = 260,865 = 3FB01h
     mov     ax, LBA_ASSIST_SPT      ; Load Sectors per Track
     xchg    cx, ax                  ; Cylinder number to AX, Sectors per Track to CX
-
 %ifdef USE_386
-    movzx   dx, [di+DPT.bLbaHeads]
+    movzx   dx, [di+DPT.bLchsHeads]
 %else
     cwd
-    mov     dl, [di+DPT.bLbaHeads]
+    mov     dl, [di+DPT.bLchsHeads]
 %endif
     mul     dx                      ; DX:AX = cylToSeek*headsPerCyl
 
     ; +=headToSeek (18-bit result)
+    ; Max = 260,865 + 254 = 261,119 = 3FBFFh
     add     al, bh                  ; Add Head number to DX:AX
     adc     ah, dh                  ; DH = Zero after previous multiplication
@@ -161 +158 @@
 
     ; *=sectPerTrack (18-bit by 6-bit multiplication with 24-bit result)
+    ; Max = 261,119 * 63 = 16,450,497 = FB03C1h
     xchg    ax, dx                  ; Hiword to AX, loword to DX
     mul     cl                      ; AX = hiword * Sectors per Track
@@ -169 +167 @@
 
     ; +=sectToSeek-1 (24-bit result)
+    ; Max = 16,450,497 + 63 - 1 = 16,450,559 = FB03FFh
     xor     bh, bh                  ; Sector number now in BX
     dec     bx                      ; sectToSeek-=1