Changeset 149 for trunk/bootcode/regular/driveio.asm

Timestamp:

Apr 8, 2017, 12:27:52 AM (8 years ago)

Author:

Ben Rietbroek

Message:

Fixed bug for new LVM sector load method [v1.1.1-testing]

Getting the LVM_SPT was done before DL was loaded with the correct
BIOS disk number. Fixed.

CAUTION:
This is a testbuild !
AirBoot uses the BIOS to access disks and a small coding error can trash
partition tables or other vital disk structures. You are advised to make
backups of TRACK0 and EBRs before using this testbuild. More info at:
​https://rousseaux.github.io/netlabs.air-boot/pdf/AirBoot-v1.1.0-manual.pdf

File:

• trunk/bootcode/regular/driveio.asm (modified) (5 diffs)

trunk/bootcode/regular/driveio.asm

@@ -437 +437 @@
 ;# EFFECTS  : Modifies DAP structure and fills or clears sector buffer
 ;# ----------------------------------------------------------------------------
-;# IN       : None   - Location info is in [CurPartition_Location]
-;# ----------------------------------------------------------------------------
-;# OUT      : CF=1   - failure, no valid LVM sector was loaded
-;#          : SI     - Points to the sector buffer ([LVMSector])
+;# IN       : MEM   - Location info is in [CurPartition_Location]
+;# ----------------------------------------------------------------------------
+;# OUT      : CF=1  - failure, no valid LVM sector was loaded
+;#          : SI    - Points to the sector buffer ([LVMSector])
 ;##############################################################################
 DriveIO_LoadLVMSector   Proc Near  Uses ax bx cx dx di
@@ -463 +463 @@
         test    byte ptr [CFG_IgnoreLVM], 1     ; ZF=0 means ignore LVM
         jnz     DIOLLVMS_NoLVMSector            ; Quit if so
-
-        ; Calculate the entry in the DISKINFO array for this disk
-        call    DriveIO_CalcDiskInfoPointer
-
-        ; If the LVM_SPT is ZERO, no LVM info is present and we quit with CY
-        mov     di, [bx+LocDISKINFO_LVM_Secs]   ; Get LVM_SPT
-        test    di, di                          ; See if it is 0
-        jz      DIOLLVMS_NoLVMSector            ; Quit if so
 
         ; Load the location of the current partition being acted upon.
@@ -485 +477 @@
         mov     cx, wptr cs:[CurPartition_Location+6]   ; BIOS cyl & sec
 
+        ; Calculate the entry in the DISKINFO array for this disk,
+        ; and put the LVM_SPT in DI
+        push    bx
+        call    DriveIO_CalcDiskInfoPointer
+        mov     di, [bx+LocDISKINFO_LVM_Secs]
+        pop     bx
+
+        ; If the LVM_SPT is ZERO, no LVM info is present and we quit with CY
+        test    di, di                          ; See if it is 0
+        jz      DIOLLVMS_NoLVMSector            ; Quit if so
+
         ; Adjust the location to point to the LVM sector
         add     ax, di      ; Add the LVM sectors-per-track
@@ -495 +498 @@
         mov     di, ds                          ; Segment of that buffer
         call    DriveIO_ReadSectorLBA           ; Read the LVM sector
-        jc      DIOLLVMS_NoLVMSector            ; Quit on error
-
-        ; Check the validity of the LVM sector, quit with CY if invalid
-        call    LVM_ValidateSector              ; Check signature and CRC
-        jnc     DIOLLVMS_NoLVMSector            ; Quit if not valid
-
 
 IFDEF   AUX_DEBUG
         IF 1
-        DBG_TEXT_OUT_AUX    'CurPartition'
+        DBG_TEXT_OUT_AUX    'LVMSecLoaded'
         PUSHRF
             call    DEBUG_DumpRegisters
@@ -513 +510 @@
         ENDIF
 ENDIF
+
+        jc      DIOLLVMS_NoLVMSector            ; Quit on error
+
+        ; Check the validity of the LVM sector, quit with CY if invalid
+        call    LVM_ValidateSector              ; Check signature and CRC
+        jnc     DIOLLVMS_NoLVMSector            ; Quit if not valid
 
         ; We're done, indicate success and return