Changeset 228 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/EBIOS

Timestamp:

Jan 29, 2012, 1:49:15 PM (13 years ago)

Author:

aitotat@…

google:author:

aitotat@gmail.com

Message:

Changes to XTIDE Universal BIOS:

• Drive size can now be limited for EBIOS functions.

File:

• trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/EBIOS/AH48h_GetExtendedDriveParameters.asm (modified) (2 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/EBIOS/AH48h_GetExtendedDriveParameters.asm

@@ -22 +22 @@
 ;--------------------------------------------------------------------
 AH48h_HandlerForGetExtendedDriveParameters:
+    call    AccessDPT_GetPointerToDRVPARAMStoCSBX
+    push    bx
     call    AccessDPT_GetLbaSectorCountToBXDXAX
+    pop     di          ; CS:DI now points to DRVPARAMS
 
     ; Point DS:SI to Extended Drive Information Table to fill
@@ -42 +45 @@
     mov     WORD [si+EDRIVE_INFO.wFlags], FLG_DMA_BOUNDARY_ERRORS_HANDLED_BY_BIOS
 
-    mov     [di+EDRIVE_INFO.qwTotalSectors], ax
+    ; Limit LBA if necessary
+    test    BYTE [cs:di+DRVPARAMS.wFlags], FLG_DRVPARAMS_USERLBA
+    jz      SHORT .StoreTotalSectorsFromBXDXAX
+    test    bx, bx
+    jnz     SHORT .LimitTotalSectors
+    cmp     dx, [cs:di+DRVPARAMS.dwMaximumLBA+2]
+    jb      SHORT .StoreTotalSectorsFromBXDXAX      ; Real size less than max
+    ja      SHORT .LimitTotalSectors
+    cmp     ax, [cs:di+DRVPARAMS.dwMaximumLBA]
+    jbe     SHORT .StoreTotalSectorsFromBXDXAX      ; Real size less than max
+
+.LimitTotalSectors:
+    xor     bx, bx
+    mov     ax, [cs:di+DRVPARAMS.dwMaximumLBA]
+    mov     dx, [cs:di+DRVPARAMS.dwMaximumLBA+2]
+
+.StoreTotalSectorsFromBXDXAX:
+    mov     [si+EDRIVE_INFO.qwTotalSectors], ax
     xor     ax, ax                                  ; Return with success
-    mov     [di+EDRIVE_INFO.qwTotalSectors+2], dx
-    mov     [di+EDRIVE_INFO.qwTotalSectors+4], bx
-    mov     [di+EDRIVE_INFO.qwTotalSectors+6], ax
-    mov     WORD [di+EDRIVE_INFO.wSectorSize], 512
+    mov     [si+EDRIVE_INFO.qwTotalSectors+2], dx
+    mov     [si+EDRIVE_INFO.qwTotalSectors+4], bx
+    mov     [si+EDRIVE_INFO.qwTotalSectors+6], ax
+    mov     WORD [si+EDRIVE_INFO.wSectorSize], 512
 
 .ReturnWithError: