Changeset 358 in xtideuniversalbios for trunk

Timestamp:

Mar 19, 2012, 2:20:32 PM (13 years ago)

Author:

aitotat@…

google:author:

aitotat@gmail.com

Message:

Changes to XTIDE Universal BIOS:

• Moved BIOS title and version strings to Version.inc.
• Moved LBA to L-CHS conversion function to LbaAssist.asm.

Location:

trunk/XTIDE_Universal_BIOS

Files:

• Inc/CustomDPT.inc (modified) (1 diff)
• Inc/Version.inc (added)
• Src/Main.asm (modified) (3 diffs)
• Src/VariablesAndDPTs/AccessDPT.asm (modified) (2 diffs)
• Src/VariablesAndDPTs/CreateDPT.asm (modified) (1 diff)
• Src/VariablesAndDPTs/LbaAssist.asm (added)

trunk/XTIDE_Universal_BIOS/Inc/CustomDPT.inc

@@ -85 +85 @@
 
 
+;--------------------------------------------------------------------
+; LIMIT_LBA_CYLINDERS_IN_DXAX_TO_LCHS_CYLINDERS
+;   Parameters:
+;       DX:AX:  Number of LBA cylinders
+;   Returns:
+;       AX:     Number of L-CHS cylinders
+;   Corrupts registers:
+;       Nothing
+;--------------------------------------------------------------------
+%macro LIMIT_LBA_CYLINDERS_IN_DXAX_TO_LCHS_CYLINDERS 0
+    test    dx, dx
+    jnz     SHORT %%LoadMaxValueToAX
+    cmp     ax, MAX_LCHS_CYLINDERS
+    jbe     SHORT %%NoNeedToModify
+%%LoadMaxValueToAX:
+    mov     ax, MAX_LCHS_CYLINDERS
+%%NoNeedToModify:
+%endmacro
+
+
 %endif ; CUSTOMDPT_INC

trunk/XTIDE_Universal_BIOS/Src/Main.asm

@@ -19 +19 @@
     ; Included .inc files
     %include "AssemblyLibrary.inc"  ; Assembly Library. Must be included first!
+    %include "Version.inc"
     %include "IntController.inc"    ; For Interrupt Controller equates
     %include "ATA_ID.inc"           ; For ATA Drive Information structs
@@ -44 +45 @@
     at  ROMVARS.bRomSize,   db  CNT_ROM_BLOCKS  ; ROM size in 512B blocks
     at  ROMVARS.rgbJump,    jmp Initialize_FromMainBiosRomSearch
-    at  ROMVARS.rgbSign,    db  "XTIDE200"      ; Signature for flash program
-    at  ROMVARS.szTitle
-        db  "-=XTIDE Universal BIOS"
-%ifdef USE_AT
-        db  " (AT)=-",NULL
-%elifdef USE_186
-        db  " (XT+)=-",NULL
-%else
-        db  " (XT)=-",NULL
-%endif
-    at  ROMVARS.szVersion,  db  "v2.0.0",BETA,"1 (",__DATE__,")",NULL
+    at  ROMVARS.rgbSign,    db  FLASH_SIGNATURE
+    at  ROMVARS.szTitle,    db  TITLE_STRING
+    at  ROMVARS.szVersion,  db  ROM_VERSION_STRING
 
 ;;; For OR'ing into wFlags below
@@ -187 +180 @@
     %include "FindDPT.asm"          ; For finding DPTs
     %include "AccessDPT.asm"        ; For accessing DPTs
+    %include "LbaAssist.asm"        ; For generating L-CHS parameters to LBA drives
     %include "BootMenuInfo.asm"     ; For creating BOOTMENUINFO structs
     %include "AtaID.asm"            ; For ATA Identify Device information

trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/AccessDPT.asm

@@ -58 +58 @@
 
     call    AccessDPT_GetLbaSectorCountToBXDXAX
-    call    AccessDPT_ConvertSectorCountFromBXDXAXtoLbaAssistedCHSinDXAXBLBH
-    test    dx, dx
-    jnz     SHORT .LimitAXtoMaxLCHScylinders
-    cmp     ax, MAX_LCHS_CYLINDERS
-    jb      SHORT .returnLCHS
-.LimitAXtoMaxLCHScylinders:
-    mov     ax, MAX_LCHS_CYLINDERS
-.returnLCHS:
+    call    LbaAssist_ConvertSectorCountFromBXDXAXtoLbaAssistedCHSinDXAXBLBH
+    LIMIT_LBA_CYLINDERS_IN_DXAX_TO_LCHS_CYLINDERS
     ret
 
@@ -157 +151 @@
     and     al, MASKL_DPT_ADDRESSING_MODE
 %endmacro
-
-
-;--------------------------------------------------------------------
-; LBA assist calculation:
-; this is how to fit a big drive into INT13's skimpy size requirements,
-; with a maximum of 8.4G available.
-;
-; total LBAs (as obtained by words 60+61)
-; divided by 63 (sectors per track) (save as value A)
-; Sub 1 from A
-; divide A by 1024 + truncate.
-; == total number of heads to use.
-; add 1
-; this value must be either 16, 32, 64, 128, or 256 (round up)
-; then take the value A above and divide by # of heads
-; to get the # of cylinders to use.
-;
-;
-; so a LBA28 drive will have 268,435,456 as maximum LBAs
-;
-; 10000000h / 63   = 410410h (total cylinders or tracks)
-;   410410h / 1024 = 1041h, which is way more than 256 heads, but 256 is max.
-;   410410h / 256  = 4104h cylinders
-;
-; there's a wealth of information at: http://www.mossywell.com/boot-sequence
-; they show a slightly different approach to LBA assist calulations, but
-; the method here provides compatibility with phoenix BIOS
-;
-; we're using the values from 60+61 here because we're topping out at 8.4G
-; anyway, so there's no need to use the 48bit LBA values.
-;
-; AccessDPT_ConvertSectorCountFromBXDXAXtoLbaAssistedCHStoDXAXBLBH:
-;   Parameters:
-;       BX:DX:AX:   Total number of sectors
-;   Returns:
-;       DX:AX:  Number of cylinders
-;       BH:     Number of sectors per track (always 63)
-;       BL:     Number of heads (16, 32, 64, 128 or 255)
-;   Corrupts registers:
-;       CX
-;--------------------------------------------------------------------
-AccessDPT_ConvertSectorCountFromBXDXAXtoLbaAssistedCHSinDXAXBLBH:
-    push    bp
-    push    si
-
-    ; Value A = Total sector count / 63
-    xor     cx, cx
-    push    cx      ; Push zero for bits 48...63
-    push    bx
-    push    dx
-    push    ax                      ; 64-bit sector count now in stack
-    mov     cl, LBA_ASSIST_SPT
-    mov     bp, sp                  ; SS:BP now points sector count
-    call    Math_DivQWatSSBPbyCX    ; Temporary value A now in stack
-
-    ; BX = Number of heads =  A / 1024
-    mov     ax, [bp]
-    mov     dx, [bp+2]
-    mov     bx, [bp+4]
-    call    Size_DivideSizeInBXDXAXby1024andIncrementMagnitudeInCX
-
-    ; Heads must be 16, 32, 64, 128 or 256 (round up)
-    mov     bx, 256                     ; Max number of heads
-    test    dx, dx                      ; 65536 or more heads?
-    jnz     SHORT .GetNumberOfCylinders
-    mov     cx, 128                     ; Half BX for rounding up
-.FindMostSignificantBitForHeadSize:
-    cmp     ax, cx
-    jae     SHORT .GetNumberOfCylinders
-    shr     cx, 1
-    shr     bx, 1                       ; Halve number of heads
-    jmp     SHORT .FindMostSignificantBitForHeadSize
-
-    ; DX:AX = Number of cylinders = A / number of heads
-.GetNumberOfCylinders:
-    mov     cx, bx
-    call    Math_DivQWatSSBPbyCX
-    mov     ax, [bp]
-    mov     dx, [bp+2]                  ; Cylinders now in DX:AX
-
-    ; Return LBA assisted CHS
-    add     sp, BYTE 8                  ; Clean stack
-    sub     bl, bh                      ; Limit heads to 255
-    mov     bh, LBA_ASSIST_SPT
-    pop     si
-    pop     bp
-    ret

trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm

@@ -113 +113 @@
 .KeepTotalSectorsFromAtaID:
     mov     bx, [di+DPT.twLbaSectors+4]     ; Restore BX
-    call    AccessDPT_ConvertSectorCountFromBXDXAXtoLbaAssistedCHSinDXAXBLBH
+    call    LbaAssist_ConvertSectorCountFromBXDXAXtoLbaAssistedCHSinDXAXBLBH
     mov     [di+DPT.bLbaHeads], bl
     jmp     SHORT .StoreBlockMode