Changeset 32 for trunk/BOOTCODE/AIR-BOOT.ASM

Timestamp:

Jan 13, 2013, 8:46:36 AM (13 years ago)

Author:

Ben Rietbroek

Message:

Fixed Win7 boot from FAT32 and HPFS zero-drive ussue [2011-11-20]

Fixes

o Fixed booting Windows 7 from FAT32

Booting Windows (NT/2K/XP/Vista/7) from FAT32 when the actual system
resides on an NTFS partition actually chainload the Windows
boot-loader in the FAT32 partition.
A bug in the handling of such a FAT32 partition with the Windows
boot-loader caused it not to find NTLDR is some cases.

o Fixed HPFS zero-drive issue

The BPB contains a field that indicates the boot-drive to the
OS2BOOT and OS2LDR programs. When creating an HPFS partition and
then restoring a system from archive (i.e. a zip-file) of course
does not set this field, since only files are restored.
This causes the boot process to halt with "...cannot operate..."
or even boot another HPFS partition. This field is now derived from
the LVM drive-letter if it contains an incorrect value.

o Corrected CRC calculations on AiR-BOOT configuration

V1.07 expanded the number of partitions from 30 to 45.
However, this was not done correctly and the configuration CRC was
still caclulated over 5 sectors. Initial v1.0.8 code corrected this
but this results in the v1.07 installer and setaboot programs
breaking on v1.0.8 code. So, for the time being the CRC caclucation
is reverted back to 5 sectors for the sake of v1.07 compatibility.
Save and restore of the configuration use 7 sectors of course.

o Corrected contact information

V1.07 shipped with the wrong contact information, causing issues
to be reported on sourceforge instead of netlabs.

Changes

o Renamed original README.TXT to README.MKW
o Added 1README.TXT
o Added COPYING (GNU License)

Note

This commit and all following commits upto and including the RC3
commit [2012-09-09] are delayed commits from a local repository.
Also, the RC (Release Candidate) naming of the corresponding commits
is a bit misleading. One would label a revision with RC when near to
a final release. Since many things have changed between RC1,RC2 & RC3,
these RC's should be interpreted as mile-stones.

WARNING!!

All commits upto and including the commit of [2012-05-13] contain
a severe bug!! Building from these sources and then disabling
the 'force LBA' feature while also using the drive-letter feature or
editing the label can destroy the MBR on all attached disks!!
DO NOT DISABLE 'FORCE LBA USAGE' WHEN BUILT FROM THE ABOVE COMMITS!!

File:

• trunk/BOOTCODE/AIR-BOOT.ASM (modified) (7 diffs)

trunk/BOOTCODE/AIR-BOOT.ASM

@@ -25 +25 @@
 ; - Fixed driveletter feature which was broken in v1.07.
 ; - Reworked MBR-code to provide two I13X signatures.
-; - Esc from SETUP would save to disk.
-;   It now retains the changes only for this boot and
-;   does not write them to disk.
+; - Fixes booting older eCS installations on HPFS
+; - Fixes booting Windows when installed in logical partition
+;   with loader on FAT32.
 ; - Corrected contact links.
-; -
+; NOTE:
+;   AB v1.07 had a bug with saving and loading the correct size of the
+;   configuration. Therefore the CRC over the config was also calculated
+;   wrongly.
+;   While AB v1.0.8 fixes this, it has to use the v1.07 way of CRC calculation.
+;   Otherwise SET(A)BOOT from the eCS v2.1 would break and reboot after phase1
+;   would show the boot-menu instead of automatically booting the system
+;   being installed. (SET(A)BOOT would see a corrupted AB config)
+;   This means that the CRC over the AB config is calculated over 5 sectors
+;   instead of 7, just like in v1.07.
+;   This will be corrected with a future release of eComStation.
+;   Note that after such a correction, an installation from a v2.1 eCS CD
+;   with a version of AiR-BOOT >v1.07 active will not automatically
+;   boot-through after phase1.
 ;
 ; v1.07
@@ -106 +119 @@
 ; If defined then include DEBUG.ASM and output debug-info to serial-port.
 ;
-AuxDebug                   equ      1
+;AuxDebug                   equ      1
 
 ; Com-port for debugging, 0 is disabled
@@ -216 +229 @@
                                              ; (relative to entry)
 
-; Rousseau: added (index in LVM-sector)
+; Rousseau: added (index in extpart LVM-sector)
 LocLVM_Secs                 equ         20h  ; Sectors per Track (OS/2 ext-geo)
 LocLVM_Heads                equ         1ch  ; Number of heads
-LocLVM_VolumeLetter2        equ         78   ; is BYTE (Letter C-Z or 0)             ; FOUT !! niet entry relative !
-LocLVM_Startable            equ         77   ; is startable (newly installed system) ; FOUT !! niet entry relative !
-LocLVM_OnBootMenu           equ         76   ; is on bootmenu                        ; FOUT !! niet entry relative !
+LocLVM_VolumeLetter2        equ         78   ; is BYTE (Letter C-Z or 0)
+LocLVM_Startable            equ         77   ; is startable (newly installed system)
+LocLVM_OnBootMenu           equ         76   ; is on bootmenu
 
 ; Truncated to 11 chars when  displayed in menu
@@ -625 +638 @@
 ; in this function. That's done around line 500.
 ; Putting this few bytes here creates just enough room.
-; The size of this function should grow.
 MBR_LoadConfig                Proc Near
-              ; Changed from conditional assembler to calculated
+              ; Changed from conditional assembler to calculated value
               ; Fixes issue: #2987 -- "air-boot doesn't remember drive letter"
-              mov     ax, (MBR_BackUpMBR - Configuration) / 2  ; sizeof(ab-configuration) to write
-            ; TASM does not evaluate expression above corrrectly.
-            ; Listing shows correct opcode but generated opcode has imm. word byteswapped.
-            ; Casting to byte also does not work (overflow).
-            ; So we swap back here -- must be removed in JWasm version !!
-               xchg    ah,al
+              ; Size of the ab-configuration in 512 byte sectors
+              mov     al, (MBR_BackUpMBR - Configuration) / 200h
               mov     ah,02h
-
               int     13h
       ret
@@ -934 +941 @@
                ; COM-PORT DEBUG
                ;
-               call     AuxIO_TeletypeNL
+;               call     AuxIO_TeletypeNL
                mov      si, offset PartitionTable
-               call     AuxIO_DumpSector
-               call     AuxIO_TeletypeNL
+;               call     AuxIO_DumpSector
+;               call     AuxIO_TeletypeNL
 
 
@@ -1130 +1137 @@
 IFDEF AuxDebug
 b_debug:
-   Include REGULAR\DEBUG.ASM     ; Various debugging routines,
+;   Include REGULAR\DEBUG.ASM     ; Various debugging routines,
                                  ; uses AUXIO and CONV
 size_debug = $-b_debug
@@ -1136 +1143 @@
 
 b_auxio:
-Include REGULAR\AUXIO.ASM        ; Com-port support for debugging
+;Include REGULAR\AUXIO.ASM        ; Com-port support for debugging
 size_auxio = $-b_auxio