Changeset 78 for trunk/bootcode/regular/partscan.asm

Timestamp:

Apr 8, 2017, 12:26:16 AM (8 years ago)

Author:

Ben Rietbroek

Message:

More hard-coded '80h' corrections [v1.1.1-testing]

Code in 'partmain.asm' around line 1350 needs some more attention.
Possibly the whole 'boot-flag' stuff is not needed with modern BIOSses.
Updating them is disabled for now, which should only affect very old
BIOSses that don't leave this checking to the MBR code.

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/partscan.asm (modified) (2 diffs)

trunk/bootcode/regular/partscan.asm

@@ -305 +305 @@
         ; Clearing the boot-flags on other disks would prevent booting them
         ; from the BIOS. (TRAC ticket #6)
-        cmp     dl, 080h                            ; See if this is boot-disk
+        cmp     dl, [BIOS_BootDisk]                 ; See if this is boot-disk
         jne     PSSP_Skip_Clear_BootFlag            ; Nope, skip clear flag
         and     byte ptr [si+LocBRPT_Flags], 7Fh    ; Reset the Active-Flag
@@ -313 +313 @@
         jb      PSSP_ScanLoop
         ; If we are on first HDD and in primary partition table -> mark primary
-        cmp     bptr [CurPartition_Location+4], 80h ; Drive
+        mov     al, [BIOS_BootDisk]
+        cmp     bptr [CurPartition_Location+4], al  ; Drive
         jne     PSSP_NoMarkPrimary
         cmp     wptr [CurPartition_Location+0], 0
         jne     PSSP_NoMarkPrimary
-        cmp     wptr [CurPartition_Location+2], 0 ; Absolute Location
+        cmp     wptr [CurPartition_Location+2], 0   ; Absolute Location
         jne     PSSP_NoMarkPrimary
         call    PART_MarkFirstGoodPrimary