Changeset 592 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/AtaGeometry.asm

Timestamp:

Jun 25, 2018, 10:29:27 PM (6 years ago)

Author:

krille_n_

Message:

Changes:

• The problem with NASM in the previous revision (r591) has been fixed.
• The colors used by the boot menu and hotkey bar can now be customized by selecting one of a number of pre-defined color themes. Suggestions for additional themes are more than welcome!
• Large builds are now 10 KB. Small builds are still 8 KB with the exception of the Tiny build which is now 4 KB. In other words, builds are now as small as possible to make it easier to combine them with other BIOSes.
• Added code to the library to improve drive error handling. XTIDECFG can now handle "Drive Not Ready" errors.
• Fixed a couple of potential bugs in AtaID.asm (AtaID_GetMaxPioModeToAXandMinCycleTimeToCX); 1) ATA1.bPioMode was treated as a WORD variable. 2) ATA2.bPIOSupp was assumed to be non-zero which would result in PIO mode 3 being returned if the assumption was wrong.
• Made the same changes in the equivalent function used by BIOSDRVS (DisplayPioModeInformationUsingAtaInfoFromDSBX in AtaInfo.asm).
• Fixed a bug from r587 in PDC20x30.asm in PDC20x30_GetMaxPioModeToALandMinPioCycleTimeToBX.
• Fixed a bug from r523 in XTIDECFG where Auto Configure would only set the IRQ on one IDE interface on AT-builds.
• XTIDECFG will now restore the default settings for the "Serial port virtual device" when reselecting it in the list of device types. This makes it behave consistently for all device types.
• The eAAM macro is now used regardless if USE_UNDOC_INTEL is defined or not because it is apparently supported on all processors including the NEC V20/V30 CPUs.
• Renamed the EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS define to EXCLUDE_FROM_XUB.
• Added a define to exclude unused library code from BIOSDRVS (EXCLUDE_FROM_BIOSDRVS). This makes it a lot smaller than in previous revisions.
• All unnecessary CLD-instructions are now under a new define 'CLD_NEEDED' which is only enabled for the BIOS. It is disabled for XTIDECFG and BIOSDRVS but can be enabled if needed by adding this define to the respective makefile. This change was made because these unnecessary instructions are wasteful and should never be needed. In fact, they only serve to hide bugs (in other peoples code) which I strongly believe should be avoided. I recommend people making their own BIOSes from source to not use this define as it's extremely unlikely to be needed.
• Updated the copyright info in SerDrive and changed an URL to point to the new site.
• Updated the copyright info and version number in BIOSDRVS.
• Updated the copyright info in XTIDECFG.
• Optimizations in general.

File:

• trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/AtaGeometry.asm (modified) (5 diffs)

trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/AtaGeometry.asm

@@ -114 +114 @@
     ; slower. The speed difference doesn't matter on AT systems.
 .UseAssistedLBA:
-    call    GetSectorCountToDXAXfromCHSinAXBLBH
-    call    ConvertChsSectorCountFromDXAXtoLbaAssistedLCHSinAXBLBH
-    xor     cx, cx      ; No bits to shift
+    ; Fall to GetSectorCountToDXAXfromCHSinAXBLBH
+
+
+;--------------------------------------------------------------------
+; GetSectorCountToDXAXfromCHSinAXBLBH
+;   Parameters:
+;       AX:     Number of cylinders (1...16383)
+;       BL:     Number of heads (1...255)
+;       BH:     Number of sectors per track (1...63)
+;   Returns:
+;       DX:AX:  Total number of CHS addressable sectors
+;   Corrupts registers:
+;       BX
+;--------------------------------------------------------------------
+GetSectorCountToDXAXfromCHSinAXBLBH:
+    xchg    ax, bx
+    mul     ah          ; AX = Heads * Sectors per track
+    mul     bx
+    ; Fall to ConvertChsSectorCountFromDXAXtoLbaAssistedLCHSinAXBLBH
+
+
+;--------------------------------------------------------------------
+; LBA assist calculation (or Assisted LBA)
+;
+; This algorithm translates P-CHS sector count up to largest possible
+; L-CHS sector count (1024, 255, 63). Note that INT 13h interface allows
+; 256 heads but DOS supports up to 255 head. That is why BIOSes never
+; use 256 heads.
+;
+; L-CHS parameters generated here require the drive to use LBA addressing.
+;
+; Here is the algorithm:
+; If cylinders > 8192
+;  Variable CH = Total CHS Sectors / 63
+;  Divide (CH - 1) by 1024 and add 1
+;  Round the result up to the nearest of 16, 32, 64, 128 and 255. This is the value to be used for the number of heads.
+;  Divide CH by the number of heads. This is the value to be used for the number of cylinders.
+;
+; ConvertChsSectorCountFromDXAXtoLbaAssistedLCHSinAXBLBH:
+;   Parameters:
+;       DX:AX:  Total number of P-CHS sectors for CHS addressing
+;               (max = 16383 * 16 * 63 = 16,514,064)
+;   Returns:
+;       AX:     Number of cylinders (?...1027)
+;       BL:     Number of heads (16, 32, 64, 128 or 255)
+;       BH:     Number of sectors per track (always 63)
+;       CX:     Number of bits shifted (0)
+;       DL:     TRANSLATEMODE_ASSISTED_LBA
+;   Corrupts registers:
+;       DH
+;--------------------------------------------------------------------
+ConvertChsSectorCountFromDXAXtoLbaAssistedLCHSinAXBLBH:
+    ; Value CH = Total sector count / 63
+    ; Max = 16,514,064 / 63 = 262128
+    mov     cx, LBA_ASSIST_SPT          ; CX = 63
+
+    ; --- Math_DivDXAXbyCX inlined (and slightly modified) since it's only used here
+    xor     bx, bx
+    xchg    bx, ax
+    xchg    dx, ax
+    div     cx
+    xchg    ax, bx
+    div     cx
+    mov     dx, bx
+    ; ---
+
+    push    ax
+    push    dx                          ; Value CH stored for later use
+
+    ; BX:DX:AX = Value CH - 1
+    ; Max = 262128 - 1 = 262127
+    xor     bx, bx
+    sub     ax, BYTE 1
+    sbb     dx, bx
+
+    ; AX = Number of heads = ((Value CH - 1) / 1024) + 1
+    ; Max = (262127 / 1024) + 1 = 256
+    call    Size_DivideSizeInBXDXAXby1024   ; Preserves CX and returns with BH cleared
+    pop     dx
+    inc     ax                          ; + 1
+
+    ; Heads must be 16, 32, 64, 128 or 255 (round up to the nearest)
+    ; Max = 255
+    mov     bl, 16                      ; Min number of heads
+.CompareNextValidNumberOfHeads:
+    cmp     ax, bx
+    jbe     SHORT .NumberOfHeadsNowInBX
+    eSHL_IM bx, 1                       ; Double number of heads
+    jpo     SHORT .CompareNextValidNumberOfHeads    ; Reached 256 heads?
+    dec     bx                          ;  If so, limit heads to 255
+.NumberOfHeadsNowInBX:
+
+    ; DX:AX = Number of cylinders = Value CH (without - 1) / number of heads
+    ; Max = 262128 / 255 = 1027
+    pop     ax                          ; Value CH back to DX:AX
+    div     bx
+
+    xchg    bh, cl                      ; Sectors per Track to BH, zero to CL (CX)
     mov     dl, TRANSLATEMODE_ASSISTED_LBA
+ReturnLCHSinAXBLBH:
     ret
 
@@ -136 +232 @@
     mov     bl, [es:si+ATA1.wHeadCnt]   ; Heads (1...16)
     mov     bh, [es:si+ATA1.wSPT]       ; Sectors per Track (1...63)
-    ret
-
-
-;--------------------------------------------------------------------
-; GetSectorCountToDXAXfromCHSinAXBLBH
-;   Parameters:
-;       AX:     Number of cylinders (1...16383)
-;       BL:     Number of heads (1...255)
-;       BH:     Number of sectors per track (1...63)
-;   Returns:
-;       DX:AX:  Total number of CHS addressable sectors
-;   Corrupts registers:
-;       BX
-;--------------------------------------------------------------------
-GetSectorCountToDXAXfromCHSinAXBLBH:
-    xchg    ax, bx
-    mul     ah          ; AX = Heads * Sectors per track
-    mul     bx
     ret
 
@@ -175 +253 @@
 ;  Do a standard ECHS translation
 ;
+; *FIXME* The above algorithm seems to be conflicting with info found here
+; https://web.archive.org/web/20000817071418/http://www.firmware.com:80/support/bios/over4gb.htm
+; which says that Revised ECHS is used when the cylinder count is > 8191.
+;
 ; ConvertPCHfromAXBLtoRevisedEnhancedCHinAXBL:
 ;   Parameters:
@@ -183 +265 @@
 ;       BL:     Number of L-CHS heads (?...240)
 ;       CX:     Number of bits shifted (0...3)
-;       DX:     ADDRESSING_MODE_NORMAL or ADDRESSING_MODE_LARGE
+;       DX:     TRANSLATEMODE_NORMAL or TRANSLATEMODE_LARGE
 ;   Corrupts registers:
 ;       Nothing
@@ -271 +353 @@
     ret
 
-
-;--------------------------------------------------------------------
-; LBA assist calculation (or Assisted LBA)
-;
-; This algorithm translates P-CHS sector count up to largest possible
-; L-CHS sector count (1024, 255, 63). Note that INT 13h interface allows
-; 256 heads but DOS supports up to 255 head. That is why BIOSes never
-; use 256 heads.
-;
-; L-CHS parameters generated here require the drive to use LBA addressing.
-;
-; Here is the algorithm:
-; If cylinders > 8192
-;  Variable CH = Total CHS Sectors / 63
-;  Divide (CH – 1) by 1024 and add 1
-;  Round the result up to the nearest of 16, 32, 64, 128 and 255. This is the value to be used for the number of heads.
-;  Divide CH by the number of heads. This is the value to be used for the number of cylinders.
-;
-; ConvertChsSectorCountFromDXAXtoLbaAssistedLCHSinAXBLBH:
-;   Parameters:
-;       DX:AX:  Total number of P-CHS sectors for CHS addressing
-;               (max = 16383 * 16 * 63 = 16,514,064)
-;   Returns:
-;       AX:     Number of cylinders (?...1027)
-;       BL:     Number of heads (16, 32, 64, 128 or 255)
-;       BH:     Number of sectors per track (always 63)
-;   Corrupts registers:
-;       CX, DX
-;--------------------------------------------------------------------
-ConvertChsSectorCountFromDXAXtoLbaAssistedLCHSinAXBLBH:
-    ; Value CH = Total sector count / 63
-    ; Max = 16,514,064 / 63 = 262128
-    mov     cx, LBA_ASSIST_SPT          ; CX = 63
-    call    Math_DivDXAXbyCX            ; Preserves CX
-    push    dx
-    push    ax                          ; Value CH stored for later use
-
-    ; BX:DX:AX = Value CH - 1
-    ; Max = 262128 - 1 = 262127
-    xor     bx, bx
-    sub     ax, BYTE 1
-    sbb     dx, bx
-
-    ; AX = Number of heads = ((Value CH - 1) / 1024) + 1
-    ; Max = (262127 / 1024) + 1 = 256
-    call    Size_DivideSizeInBXDXAXby1024   ; Preserves CX
-    inc     ax                          ; + 1
-
-    ; Heads must be 16, 32, 64, 128 or 255 (round up to the nearest)
-    ; Max = 255
-    mov     cl, 16                      ; Min number of heads
-.CompareNextValidNumberOfHeads:
-    cmp     ax, cx
-    jbe     SHORT .NumberOfHeadsNowInCX
-    eSHL_IM cx, 1                       ; Double number of heads
-    jpo     SHORT .CompareNextValidNumberOfHeads    ; Reached 256 heads?
-    dec     cx                          ;  If so, limit heads to 255
-.NumberOfHeadsNowInCX:
-    mov     bx, cx                      ; Number of heads are returned in BL
-    mov     bh, LBA_ASSIST_SPT          ; Sectors per Track
-
-    ; DX:AX = Number of cylinders = Value CH (without - 1) / number of heads
-    ; Max = 262128 / 255 = 1027
-    pop     ax
-    pop     dx                          ; Value CH back to DX:AX
-    div     cx
-
-    ; Return L-CHS
-ReturnLCHSinAXBLBH:
-    ret