Changeset 530 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Initialization

Timestamp:

Mar 28, 2013, 1:36:23 PM (12 years ago)

Author:

aitotat@…

google:author:

aitotat@gmail.com

Message:

Changes to XTIDE Universal BIOS:

• AT builds again copy old INT 13h handler to 40h. It turned out it is needed, by XTIDE Universal BIOS at least (fixes disappearing floppy drive hotkey button when booting starts).
• AH=48h no longer returns P-CHS parameteres for drives with more than 15,482,880 sectors (now works like described on Phoenix specification).

Location:

trunk/XTIDE_Universal_BIOS/Src/Initialization

Files:

• FloppyDrive.asm (modified) (10 diffs)
• Interrupts.asm (modified) (2 diffs)

trunk/XTIDE_Universal_BIOS/Src/Initialization/FloppyDrive.asm

@@ -22 +22 @@
 SECTION .text
 
-%ifdef COPY_13H_HANDLER_TO_40H
 ;--------------------------------------------------------------------
 ; Checks is floppy drive handler installed to interrupt vector 40h.
@@ -36 +35 @@
 ;--------------------------------------------------------------------
 FloppyDrive_IsInt40hInstalled:
-    cmp     WORD [es:BIOS_DISKETTE_INTERRUPT_40h*4+2], 0C000h   ; Any ROM segment?
-%ifdef USE_AT   ; No need to verify on XT systems.
-    jb      SHORT .Int40hHandlerIsNotInstalled
-    call    .VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h
-.Int40hHandlerIsNotInstalled:
-%endif
-    cmc
-    ret
-
-;--------------------------------------------------------------------
-; .VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h
-;   Parameters:
-;       Nothing
-;   Returns:
-;       CF:     Cleared if INT 40h is installed
-;               Set if INT 40h is not installed
-;   Corrupts registers:
-;       BX, CX, DI
-;--------------------------------------------------------------------
 %ifdef USE_AT
-.VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h:
     push    es
     push    dx
     push    ax
 
-    call    .LoadInt40hVerifyParameters
+    call    LoadInt40hVerifyParameters
     int     BIOS_DISK_INTERRUPT_13h
     jc      SHORT .Int40hIsInstalled    ; Maybe there are not any floppy drives at all
-    push    es
-    push    di
+    push    es                          ; Drive Parameter Table segment
+    push    di                          ; Drive Parameter Table offset
 
-    call    .LoadInt40hVerifyParameters
+    call    LoadInt40hVerifyParameters
     int     BIOS_DISKETTE_INTERRUPT_40h
 
@@ -83 +62 @@
     pop     dx
     pop     es
+
+%else ; if XT build
+    cmp     WORD [es:BIOS_DISKETTE_INTERRUPT_40h*4+2], 0C000h   ; Any ROM segment? (set CF if not)
+%endif ; USE_AT
+    cmc
     ret
 
 ;--------------------------------------------------------------------
-; .LoadInt40hVerifyParameters
+; LoadInt40hVerifyParameters
 ;   Parameters:
 ;       Nothing
@@ -96 +80 @@
 ;       DH
 ;--------------------------------------------------------------------
-.LoadInt40hVerifyParameters:
-    mov     ah, 08h             ; Get Drive Parameters
-    cwd                         ; Floppy drive 0
+%ifdef USE_AT
+LoadInt40hVerifyParameters:
+    mov     ah, GET_DRIVE_PARAMETERS
+    cwd                     ; Floppy drive 0
     mov     di, dx
-    mov     es, dx              ; ES:DI = 0000:0000h to guard against BIOS bugs
+    mov     es, dx          ; ES:DI = 0000:0000h to guard against BIOS bugs
     ret
 %endif
-
-%endif ; COPY_13H_HANDLER_TO_40H
 
 
@@ -130 +113 @@
 %ifdef MODULE_BOOT_MENU
 FloppyDrive_GetType:
-    mov     ah, 08h         ; Get Drive Parameters
+    mov     ah, GET_DRIVE_PARAMETERS
     xor     bx, bx          ; FLOPPY_TYPE_525_OR_35_DD when function not supported
     int     BIOS_DISKETTE_INTERRUPT_40h
@@ -151 +134 @@
     js      .UseBIOSorBDA               ; We didn't add in any drives, counts here are not valid
 
-    adc     al,1                        ; adds in the drive count bit, and adds 1 for count vs. 0-index,
+    adc     al ,1                       ; adds in the drive count bit, and adds 1 for count vs. 0-index,
     jmp     .FinishCalc                 ; need to clear AH on the way out, and add in minimum drive numbers
 
@@ -165 +148 @@
     ret
 
-FloppyDrive_GetCountFromBIOS_or_BDA:
-    push    es
 
 ;--------------------------------------------------------------------
-; Reads Floppy Drive Count from BIOS.
-; Does not work on most XT systems. Call .GetCountFromBDA
-; if this function fails.
-;
-; .GetCountFromBIOS
+; FloppyDrive_GetCountFromBIOS_or_BDA
 ;   Parameters:
 ;       Nothing
@@ -181 +158 @@
 ;               Set if BIOS function not supported
 ;   Corrupts registers:
-;       ES
+;       AH, ES
 ;--------------------------------------------------------------------
+FloppyDrive_GetCountFromBIOS_or_BDA:
+    push    es
+
+; Reads Floppy Drive Count from BIOS.
+; Does not work on most XT systems. Call .GetCountFromBDA
+; if this function fails.
 %ifdef USE_AT
-.GetCountFromBIOS:
     push    di
     push    bx
@@ -190 +172 @@
     push    dx
 
-    mov     ah, 08h                 ; Get Drive Parameters
+    mov     ah, GET_DRIVE_PARAMETERS
     cwd                             ; Floppy Drive 00h
     int     BIOS_DISKETTE_INTERRUPT_40h
@@ -199 +181 @@
     pop     bx
     pop     di
-%endif
 
-;--------------------------------------------------------------------
 ; Reads Floppy Drive Count (0...4) from BIOS Data Area.
 ; This function should be used only if .GetCountFromBIOS fails.
-;
-; .GetCountFromBDA
-;   Parameters:
-;       Nothing
-;   Returns:
-;       AL:     Number of Floppy Drives
-;   Corrupts registers:
-;       AH, ES
-;--------------------------------------------------------------------
-%ifndef USE_AT
-.GetCountFromBDA:
+%else ; ifndef USE_AT
     LOAD_BDA_SEGMENT_TO es, ax
-    mov     al, [es:BDA.wEquipment]         ; Load Equipment WORD low byte
-    mov     ah, al                          ; Copy it to AH
-    and     ax, 0C001h                      ; Leave bits 15..14 and 0
-    eROL_IM ah, 2                           ; EW low byte bits 7..6 to 1..0
-    add     al, ah                          ; AL = Floppy Drive count
+    mov     al, [es:BDA.wEquipment] ; Load Equipment WORD low byte
+    mov     ah, al                  ; Copy it to AH
+    and     ax, 0C001h              ; Leave bits 15..14 and 0
+    eROL_IM ah, 2                   ; EW low byte bits 7..6 to 1..0
+    add     al, ah                  ; AL = Floppy Drive count
 %endif
 

trunk/XTIDE_Universal_BIOS/Src/Initialization/Interrupts.asm

@@ -64 +64 @@
     mov     [RAMVARS.fpOldI13h], ax             ; Store old INT 13h offset
 
-%ifdef COPY_13H_HANDLER_TO_40H
     ; Only store INT 13h handler to 40h if 40h is not already installed.
     ; At least AMI BIOS for 286 stores 40h handler by itself and calls
-    ; 40h from 13h. That system locks to infinite loop if we copy 13h to 40h.
+    ; 40h from 13h. That system locks to infinite loop if we blindly copy 13h to 40h.
     call    FloppyDrive_IsInt40hInstalled
     jc      SHORT .Int40hAlreadyInstalled
@@ -73 +72 @@
     mov     [es:BIOS_DISKETTE_INTERRUPT_40h*4+2], dx    ; Store old INT 13h segment
 .Int40hAlreadyInstalled:
-%endif ; COPY_13H_HANDLER_TO_40H
 
     mov     al, BIOS_DISK_INTERRUPT_13h         ; INT 13h interrupt vector offset