Changeset 158

Timestamp:

Apr 8, 2017, 12:27:59 AM (8 years ago)

Author:

Ben Rietbroek

Message:

Preserve SI when using 'LVM_GetDriveLetter' [v1.1.1-testing]

In several parts of the code, SI points to the IPT-entry of the
partition acted upon and is often assumed to be preserved across
helper functions.

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/special/lvm.asm (modified) (4 diffs)

trunk/bootcode/special/lvm.asm

@@ -225 +225 @@
 ; IN    : SI    - Pointer to IPT entry for partition
 ; OUT   : AL    - LVM drive-letter
-;       : SI    - Pointer to LVM entry in loaded LVM record
 ;       : CF=1  - No valid LVM sector found, AL not valid
 ; NOTE  : Besides the drive-letter, AL can be 0 (LVM hidden) or '*' (LVM auto)
 ;------------------------------------------------------------------------------
-LVM_GetDriveLetter      Proc Near   Uses bx cx dx di
+LVM_GetDriveLetter      Proc Near   Uses bx cx dx si di
 
 IFDEF   AUX_DEBUG
@@ -275 +274 @@
         ; Indicate no LVM drive-letter found
         xor     ax, ax
-        mov     si, ax
         stc
 
@@ -303 +301 @@
 ; IN    : SI    - Pointer to IPT entry for partition
 ;       : AL    - LVM drive-letter
-; OUT   : SI    - Pointer to LVM entry in loaded (and saved) LVM record
-;       : AL    - LVM drive-letter
-;       : CF=1  - No valid LVM sector found, AL not valid
+; OUT   : CF=1  - No valid LVM sector found, AL was not valid
 ; NOTE  : Besides the drive-letter, AL can be 0 (LVM hidden) or '*' (LVM auto)
 ;------------------------------------------------------------------------------
-LVM_SetDriveLetter      Proc Near   Uses bx cx dx di
+LVM_SetDriveLetter      Proc Near   Uses bx cx dx si di
 
         ; THIS IS A DUMMY FUNCTION RETURNING FAILURE
@@ -320 +316 @@
         ; Just indicate failure and return
         xor     ax, ax
-        mov     si, ax
         stc
         ret