Changeset 568 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/Tools/Address.asm

Timestamp:

Dec 21, 2014, 5:37:53 PM (9 years ago)

Author:

krille_n_@…

google:author:

krille_n_@hotmail.com

Message:

Changes:

• SerDrive: Using named pipe mode (serdrive -p) now works under Windows XP/2000/Server 2003.
• checksum.pl: Added a compatibility fix for 3Com 3C503 cards.
• XTIDECFG will now scan every possible segment address to find and load the BIOS and/or its settings from EEPROM. This should simplify things for people using combined option ROMs.
• Fixed a bug from r521 in BootSector.asm where the BIOS would not display a timeout error if it failed to load the boot sector from harddrive.
• Fixed a bug from r541 in CompatibleDPT.asm where CompatibleDPT_CreateDeviceParameterTableExtensionToESBXfromDPTinDSSI would generate an invalid checksum in the DPTE.
• Optimizations and other fixes.

File:

• trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/Tools/Address.asm (modified) (4 diffs)

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

@@ -37 +37 @@
 ALIGN JUMP_ALIGN
 Address_ExtractLCHSparametersFromOldInt13hAddress:
-    mov     bl, cl              ; Copy sector number...
-    and     bl, 3Fh             ; ...and limit to 1...63
+    mov     bl, 3Fh             ; Load sector number mask
+    and     bl, cl              ; Sector number now in BL
     sub     cl, bl              ; Remove from cylinder number high
     eROL_IM cl, 2               ; High bits to beginning
@@ -75 +75 @@
     ; (LCylinder << n) + (LHead / PHeadCount)
     mov     dx, cx                  ; Copy L-CHS Cylinder number to DX
-    mov     cl, [di+DPT.bFlagsLow]  ; Load shift count
-    and     cl, MASKL_DPT_CHS_SHIFT_COUNT
+    mov     cl, MASKL_DPT_CHS_SHIFT_COUNT   ; Load shift count mask
+    and     cl, [di+DPT.bFlagsLow]  ; Shift count now in CL
     shl     dx, cl                  ; DX = LCylinder << n
     add     ax, dx                  ; AX = P-CHS Cylinder number
@@ -83 +83 @@
     ret
 
+; *FIXME* The above function description doesn't match the code.
+; If CX has a maximum value of 1023 on entry then there is no way CX can be 16382 on return.
+; 1023 SHL 3 (MASKL_DPT_CHS_SHIFT_COUNT) is 8184. With the addition of AX (at most 255?)
+; the result is 8439.
 
 ;--------------------------------------------------------------------
@@ -102 +106 @@
 ALIGN JUMP_ALIGN
 Address_OldInt13hAddressToIdeAddress:
-        call    Address_ExtractLCHSparametersFromOldInt13hAddress
-        ACCESSDPT__GET_UNSHIFTED_TRANSLATE_MODE_TO_AXZF
+    call    Address_ExtractLCHSparametersFromOldInt13hAddress
+    mov     al, [di+DPT.bFlagsLow]
+    and     al, MASKL_DPT_TRANSLATEMODE
 
 ;;; 0: ADDRESSING_MODE_NORMAL
-        jz      SHORT DoNotConvertLCHS
+    jz      SHORT DoNotConvertLCHS
 
 ;;; 1: ADDRESSING_MODE_LARGE
-        test    al, FLGL_DPT_ASSISTED_LBA
-        jz      SHORT ConvertLargeModeLCHStoPCHS
+    test    al, FLGL_DPT_ASSISTED_LBA
+    jz      SHORT ConvertLargeModeLCHStoPCHS
 
 ;;; 2: ADDRESSING_MODE_ASSISTED_LBA
-        ; Fall through to ConvertAssistedLBAModeLCHStoLBARegisterValues
+    ; Fall to ConvertAssistedLBAModeLCHStoLBARegisterValues