11 replies to this topic

[Bukvod]

Hello all,
I have recently required the need to boot dos,windows xp and windows 7 off the same computer and would like to install grub4dos and boot everything from there.
I have tried only MS Dos 6.2.2 with this as my menu entry:

title 08 - MS-DOS  Direct Load io.sys

find --set-root --ignore-floppies /io.sys

chainloader /io.sys

But grub gives me the error 13 unsupported file (or something simular wording)
What do I need to do? install grub4dos then install dos? Any Help?

P.S. I hope this post is in the right area, sorry if not.

[Wonko the Sane]

But grub gives me the error 13 unsupported file (or something simular wording)

Direct chainloading of DOS 6.22 is NOT supported.
It will work for DOS 7.x/8.x, though.
Of course the DOS needs to reside on a FAT12 or FAT16 or FAT32 partition.
The most practical way is since you have triple booting with XP and 7 it is likely you are using NTFS formatted volumem, is to have DOS inside an image.

If you do have a volume formatted as FAT12 or FAT16 and you want to run DOS <=6.22, you need to have the volume have a bootsector invoking the DOS, then:

title 08 - MS-DOS 6.22  INdirect Load io.sys

find --set-root --ignore-floppies /io.sys

chainloader +1

Or in the case of a hard disk image (example):

find --set-root /mydos622.img

map /mydos622.img (hd1)

map (hd0) (hd1)

map (hd1) (hd0)

map --hook

root (hd0,0)

chainloader +1

Remember that DOS wants to be booted from first drive (drive 128 or 0x80 in DOS or (hd0) in grub4dos naming )

NEVER use a pre-made entry when experimenting, ALWAYS use command line, typing command line by line as you will have a much better feedback.

Read:
http://diddy.boot-la...iles/basics.htm
http://diddy.boot-la...s/files/cli.htm


Wonko

[Bukvod]

Direct chainloading of DOS 6.22 is NOT supported.
It will work for DOS 7.x/8.x, though.
Of course the DOS needs to reside on a FAT12 or FAT16 or FAT32 partition.
The most practical way is since you have triple booting with XP and 7 it is likely you are using NTFS formatted volumem, is to have DOS inside an image.

If you do have a volume formatted as FAT12 or FAT16 and you want to run DOS <=6.22, you need to have the volume have a bootsector invoking the DOS, then:

title 08 - MS-DOS 6.22  INdirect Load io.sys

find --set-root --ignore-floppies /io.sys

chainloader +1

Or in the case of a hard disk image (example):

find --set-root /mydos622.img

map /mydos622.img (hd0)

map (hd0) (hd1)

map --hook

root (hd0,0)

chainloader +1

Remember that DOS wants to be booted from first drive (drive 128 or 0x80 in DOS or (hd0) in grub4dos naming )

NEVER use a pre-made entry when experimenting, ALWAYS use command line, typing command line by line as you will have a much better feedback.

Read:
http://diddy.boot-la...iles/basics.htm
http://diddy.boot-la...s/files/cli.htm


Wonko

[Bukvod]

Thanks I will post my results

[Wonko the Sane]

Thanks I will post my results

WARNING!

Sorry I had a typo, should be:
Or in the case of a hard disk image (example):

find --set-root /mydos622.img

map /mydos622.img (hd1)

map --hook

map (hd0) (hd1)

map (hd1) (hd0)

map --hook

root (hd0,0)

chainloader +1

(also corrected in previous post)
or:

find --set-root /mydos622.img

map (hd0) (hd1)

map /mydos622.img (hd0)

map --hook

root (hd0,0)

chainloader +1

This applies to a system with a single drive (hd0), you map the image ot second drive and then exchange the drive order.


Wonko

[steve6375]

I prepared a bootable HDD image using QEMU Manager as follows:

1. Run QEMU Manager with HDD0 as a qcow empty 100MB disk image and FDD0 as a DOS 6.22 bootable floppy image
2. Run FDISK and Format /s to make a bootable FAT16 drive C: (Ptn 1 at sector 63 MSDOS 5.0 boot sector)
3. Check I can boot to the C: drive image under QEMU
4. Use RMPrepUSB File->Drive to convert the qcow HDD image to RAW and write it to the USB drive
5. Check USB drive boots under QEMU as C:
6. Install grub4dos and use chainloader /io.sys to boot it

RESULT: ALL OK

Now I have bootable C: drive with or without grub4dos


Now the strange bit:

1. Reformat the USB drive as a FAT16 disk 100MB using RMPrepUSB (MS-DOS boot partition)
2. Copy over IO.SYS from the working image so it is first on the drive root
3. Copy over other files ( first msdos.sys, then drvspace.bin, autoexec.bat, command.com)
4. Check it boots - DOES NOT BOOT - get Starting MS-DOS...

[Wonko the Sane]

1. Reformat the USB drive as a FAT16 disk 100MB using RMPrepUSB
2. Copy over IO.SYS from the working image so it is first on the drive root
3. Copy over other files ( first msdos.sys, then drvspace.bin, autoexec.bat, command.com)
4. Check it boots - DOES NOT BOOT - get Starting MS-DOS...

Hmmm.

Please:

• Re-do with a RAW (and NOT Qcow) image.
  
• Backup the MBR and PBR of the image.
  
• Use again RMPREPUSB
  
• Backup the MBR and PBR of the image.
  
• Compress all 4 files in a .zip and attach it.

Be aware that if you used the "LABEL" command, the LABEL is an entry in ROOT , see here:
http://www.msfn.org/...at-b-and-label/

Alternatively, try running bootpart to make sure that IO.SYS is first file:
http://www.winimage.com/bootpart.htm


Wonko

[0scar]

I can boot anything from boot.ini using bootpart.exe

Boot Partition 2.60 for WinNT/2K/XP ©1995-2005 G. Vollant (info@winimage.com)
WEB : http://www.winimage.com and http://www.winimage.com/bootpart.htm
Add partition in the Windows NT/2000/XP Multi-boot loader
Usage : When running under Windows NT/2000/XP/2003 server or MS-Dos
BOOTPART
List all partition, with number
BOOTPART <part_number> [LBA] <filename> [<name_of_system>]
where : part_number : a number of a partition (or A: for floppy)
LBA : force LBA addressing for loading partition bootsector
filename : the file name of the bootfile to create
name_of_system : the name to be added in the BOOT.INI
Create a boot file for the partition, and if name_of_system
is specified, register it in the BOOT.INI
You can also replace <part_number> by DOS622 or WIN95 to them.
BOOTPART LIST
List entry in BOOT.INI (you can remove them after with BOOTPART)
Under MS-Dos (MS-Dos 6.22 or the "MS-Dos 7.0" from Windows 95) only:
BOOTPART <part_type> BOOT:C:
where <part_type> is DOS622, WIN95, WINNT, VISTA: rewrite boot sector
of C: for boot under MS-Dos 6.22, Win95 or the NT Boot loader
BOOTPART REWRITEROOT:C:
Put the IO.SYS and MSDOS.SYS file from MS-Dos 6.22 at the beginning
of the boot sector

[steve6375]

With a FAT16 FS - The file order is IO.SYS, MSDOS.SYS, COMMAND.COM (no volume label entry). If I rename IO.SYS to IM.SYS then when it boots I just get 'Error!'. So I conclude that at least IO.SYS is being loaded. If I rename MSDOS.SYS to XMSDOS.SYS then I get 'Non-system disk or disk error' - so I conclude that MSDOS.SYS is also being loaded correctly. It just seems to hang after that for some reason...

[Wonko the Sane]

With a FAT16 FS - The file order is IO.SYS, MSDOS.SYS, COMMAND.COM (no volume label entry). If I rename IO.SYS to IM.SYS then when it boots I just get 'Error!'. So I conclude that at least IO.SYS is being loaded. If I rename MSDOS.SYS to XMSDOS.SYS then I get 'Non-system disk or disk error' - so I conclude that MSDOS.SYS is also being loaded correctly. It just seems to hang after that for some reason...

But it is working when you FDISK and format from a MS-DOS floppy, right?
So *something* is different when you use RMPREPUSB.
If you can provide the mentioned data I may compare them.
Or if you could detail how EXACTLY you used RMPREPUSB I could attempt to replicate the behaviour.
What happens using bootpart on the non-working setup?


Wonko

[steve6375]

RMPrepUSB is set to 100MB, MSDOS, FAT16 (no special options ticked) and click Prepare. Then I copy over IO.SYS, then MSDOS.SYS then COMMAND.COM.
The bootcode installed by RMPrepUSB is a later version that does not need IO.SYS to be the first entry. If you replace it with the old 6.22 boot code then you must change the root directory to remove the volume label entry. Either way it just says 'Starting MS-DOS...' and halts.


WORKING (made from HDD IMAGE under an emulator and copies to USB drive)
[Sector 63] 0MB
0000 EB 3C 90 4D 53 44 4F 53 - 35 2E 30 00 02 04 01 00 ë<MSDOS 5.0.....
0010 02 00 02 00 00 F8 C7 00 - 3F 00 10 00 3F 00 00 00 .....øÇ. ?..?...
0020 21 1B 03 00 80 00 29 02 - 13 2E 36 44 4F 53 36 32 !..€.). .6DOS62
0030 32 20 20 20 20 20 46 41 - 54 31 36 20 20 20 FA 33 2 FA T16 ú3
0040 C0 8E D0 BC 00 7C 16 07 - BB 78 00 36 C5 37 1E 56 ÀŽÐ¼.|. »x.6Å7V
0050 16 53 BF 3E 7C B9 0B 00 - FC F3 A4 06 1F C6 45 FE S¿>|¹.. üó¤.ÆEþ
0060 0F 8B 0E 18 7C 88 4D F9 - 89 47 02 C7 07 3E 7C FB ‹|ˆMù ‰G.Ç.>|û
0070 CD 13 72 79 33 C0 39 06 - 13 7C 74 08 8B 0E 13 7C Íry3À9. |t.‹|
0080 89 0E 20 7C A0 10 7C F7 - 26 16 7C 03 06 1C 7C 13 ‰ | |÷ &|..|
0090 16 1E 7C 03 06 0E 7C 83 - D2 00 A3 50 7C 89 16 52 |..|ƒ Ò.£P|‰R
00A0 7C A3 49 7C 89 16 4B 7C - B8 20 00 F7 26 11 7C 8B |£I|‰K| ¸ .÷&|‹
00B0 1E 0B 7C 03 C3 48 F7 F3 - 01 06 49 7C 83 16 4B 7C .|.ÃH÷ó ..I|ƒK|
00C0 00 BB 00 05 8B 16 52 7C - A1 50 7C E8 92 00 72 1D .»..‹R| ¡P|è’.r
00D0 B0 01 E8 AC 00 72 16 8B - FB B9 0B 00 BE E6 7D F3 °.è¬.r‹ û¹..¾Æ}ó
00E0 A6 75 0A 8D 7F 20 B9 0B - 00 F3 A6 74 18 BE 9E 7D ¦u. ¹. .ó¦t¾ž}
00F0 E8 5F 00 33 C0 CD 16 5E - 1F 8F 04 8F 44 02 CD 19 è_.3ÀÍ^ .D.Í
0100 58 58 58 EB E8 8B 47 1A - 48 48 8A 1E 0D 7C 32 FF XXXëè‹G HHŠ.|2ÿ
0110 F7 E3 03 06 49 7C 13 16 - 4B 7C BB 00 07 B9 03 00 ÷Ã..I| K|»..¹..
0120 50 52 51 E8 3A 00 72 D8 - B0 01 E8 54 00 59 5A 58 PRQè:.rø °.èT.YZX
0130 72 BB 05 01 00 83 D2 00 - 03 1E 0B 7C E2 E2 8A 2E r»...ƒÒ. ..|ââŠ.
0140 15 7C 8A 16 24 7C 8B 1E - 49 7C A1 4B 7C EA 00 00 |Š$|‹ I|¡K|ê..
0150 70 00 AC 0A C0 74 29 B4 - 0E BB 07 00 CD 10 EB F2 p.¬.Àt)´ »..ÍëÒ
0160 3B 16 18 7C 73 19 F7 36 - 18 7C FE C2 88 16 4F 7C ;|s÷6 |þâˆO|
0170 33 D2 F7 36 1A 7C 88 16 - 25 7C A3 4D 7C F8 C3 F9 3Ò÷6|ˆ %|£M|øÃù
0180 C3 B4 02 8B 16 4D 7C B1 - 06 D2 E6 0A 36 4F 7C 8B ô.‹M|± .ÒÆ.6O|‹
0190 CA 86 E9 8A 16 24 7C 8A - 36 25 7C CD 13 C3 0D 0A ê†éŠ$|Š 6%|ÍÃ..
01A0 4E 6F 6E 2D 53 79 73 74 - 65 6D 20 64 69 73 6B 20 Non-Syst em disk
01B0 6F 72 20 64 69 73 6B 20 - 65 72 72 6F 72 0D 0A 52 or disk error..R
01C0 65 70 6C 61 63 65 20 61 - 6E 64 20 70 72 65 73 73 eplace a nd press
01D0 20 61 6E 79 20 6B 65 79 - 20 77 68 65 6E 20 72 65 any key when re
01E0 61 64 79 0D 0A 00 49 4F - 20 20 20 20 20 20 53 59 ady...IO SY
01F0 53 4D 53 44 4F 53 20 20 - 20 53 59 53 00 00 55 AA SMSDOS SYS..Uª


RMPrepUSB formatted - Not Working


[Sector 63] 0MB
0000 EB 3C 90 4D 53 44 4F 53 - 35 2E 30 00 02 04 01 00 ë<MSDOS 5.0.....
0010 02 00 02 00 00 F8 00 01 - 3F 00 FF 00 3F 00 00 00 .....ø.. ?.ÿ.?...
0020 CD F0 02 00 80 00 29 46 - 94 BF 15 4E 4F 20 4E 41 ÍÐ..€.)F ”¿NO NA
0030 4D 45 20 20 20 20 46 41 - 54 31 36 20 20 20 33 C0 ME FA T16 3À
0040 8E D8 8E D0 BC 00 7C 8B - EC FC FB 88 56 24 8A 46 ŽøŽÐ¼.|‹ ìüûˆV$ŠF
0050 10 F7 66 16 03 46 0E 12 - D6 03 46 1C 13 56 1E 6A ÷f.F Ö.FVj
0060 54 07 1E BB 3A 05 BE 00 - 7E 8B 4E 11 06 E8 EB 00 T.»:.¾. ~‹N.èë.
0070 07 BF 00 02 83 EF 20 72 - F3 56 8D 74 F0 38 7C 0F .¿..ƒï r óVtÐ8|
0080 72 21 60 77 0A A0 17 04 - 24 0F 3A 44 0E 75 05 B9 r!`w. . $ u.¹
0090 0B 00 F3 A6 61 75 E3 FF - 71 20 39 5C 0C 75 DA 8F ..ó¦auÃÿ q 9\.uú
00A0 07 EB D7 5E E2 CE 5F 8B - E5 89 7F E0 52 50 C4 5C .ë×^âÎ_‹ ʼnÀRPÄ\
00B0 0A 86 F9 06 57 8A 5E 0D - 8D 45 FE F7 E3 03 46 FC .†ù.WŠ^. Eþ÷Ã.Fü
00C0 13 56 FE 0B FF 74 79 E8 - 91 00 4B E0 FA E3 4F 51 Vþ.ÿtyè ‘.KÀúÃOQ
00D0 8B C7 8A C4 25 F0 00 3B - C6 74 1C 8B F0 06 68 E0 ‹ÇŠÄ%Ð.; Æt‹Ð.hÀ
00E0 07 07 99 03 46 0E 13 D2 - 03 46 1C 13 56 1E B9 10 ..™.FÒ .FV¹
00F0 00 E8 67 00 E2 FB 07 B9 - FF 0F 23 F9 8B C7 03 F8 .èg.âû.¹ ÿ#ù‹Ç.ø
0100 03 F8 80 7E 3A 36 75 04 - 03 F8 8A E9 D1 EF 8B BD .ø€~:6u. .øŠéÑ
0110 00 7E 73 03 C1 EF 04 23 - F9 3B F9 59 75 97 5F 07 .~s.Áï.# ù;ùYu—_.
0120 8A 56 24 8A 6E 15 8D 76 - 0B 33 DB 26 81 3F 4D 5A ŠV$Šnv .3û&?MZ
0130 74 1E 5B 58 06 16 CB 5A - B4 00 CD 13 3B E6 75 2F t[X.ëZ ´.Í;Æu/
0140 BE C8 7D AC 84 C0 74 FC - B4 0E B3 07 CD 10 EB F3 ¾è}¬„Àtü ´³.Íëó
0150 66 FF 77 78 55 16 06 68 - 00 02 CB 60 06 16 16 52 fÿwxU.h ..ë`.R
0160 50 06 16 6A 01 6A 10 8B - F4 8A 56 24 52 52 52 B4 P.j.j‹ ôŠV$RRR´
0170 08 CD 13 C4 5C 04 72 BF - 83 E1 3F 89 4E 18 0F B6 .ÍÄ\.r¿ ƒÁ?‰N¶
0180 C6 40 89 46 1A F7 E1 97 - 8B 44 08 8B 54 0A 74 1A Æ@‰F÷Á— ‹D.‹T.t
0190 3B D7 73 16 F7 F7 92 F6 - F1 B1 02 86 EA D3 EA 86 ;×s÷÷’Ö Ñ±.†êóê†
01A0 E1 41 0A CA 86 F0 0A C0 - 74 08 B4 42 16 07 C6 46 ÁA.ê†Ð.À t.´B.ÆF
01B0 02 0E 40 8A 56 24 CD 13 - 72 BC 8D 64 10 83 44 10 .@ŠV$Í r¼dƒD
01C0 20 07 61 40 73 01 42 C3 - 45 72 72 6F 72 21 00 00 .a@s.BÃ Error!..
01D0 57 49 4E 42 4F 4F 54 20 - 53 59 53 04 70 00 00 06 WINBOOT SYS.p...
01E0 4D 53 44 4F 53 20 20 20 - 53 59 53 04 3A 05 C5 7D MSDOS SYS.:.Å}
01F0 49 4F 20 20 20 20 20 20 - 53 59 53 04 70 00 55 AA IO SYS.p.Uª

Modified RMPrepUSb - still hangs at Starting MS-DOS if IO.SYS is first in root folder, followed by MS-DOS etc.

[Sector 63] 0MB
0000 EB 3C 90 4D 53 44 4F 53 - 35 2E 30 00 02 04 01 00 ë<MSDOS 5.0.....
0010 02 00 02 00 00 F8 00 01 - 3F 00 FF 00 3F 00 00 00 .....ø.. ?.ÿ.?...
0020 CD F0 02 00 80 00 29 35 - B7 8F B4 4E 4F 20 4E 41 ÍÐ..€.)5 ·´NO NA
0030 4D 45 20 20 20 20 46 41 - 54 31 36 20 20 20 FA 33 ME FA T16 ú3
0040 C0 8E D0 BC 00 7C 16 07 - BB 78 00 36 C5 37 1E 56 ÀŽÐ¼.|. »x.6Å7V
0050 16 53 BF 3E 7C B9 0B 00 - FC F3 A4 06 1F C6 45 FE S¿>|¹.. üó¤.ÆEþ
0060 0F 8B 0E 18 7C 88 4D F9 - 89 47 02 C7 07 3E 7C FB ‹|ˆMù ‰G.Ç.>|û
0070 CD 13 72 79 33 C0 39 06 - 13 7C 74 08 8B 0E 13 7C Íry3À9. |t.‹|
0080 89 0E 20 7C A0 10 7C F7 - 26 16 7C 03 06 1C 7C 13 ‰ | |÷ &|..|
0090 16 1E 7C 03 06 0E 7C 83 - D2 00 A3 50 7C 89 16 52 |..|ƒ Ò.£P|‰R
00A0 7C A3 49 7C 89 16 4B 7C - B8 20 00 F7 26 11 7C 8B |£I|‰K| ¸ .÷&|‹
00B0 1E 0B 7C 03 C3 48 F7 F3 - 01 06 49 7C 83 16 4B 7C .|.ÃH÷ó ..I|ƒK|
00C0 00 BB 00 05 8B 16 52 7C - A1 50 7C E8 92 00 72 1D .»..‹R| ¡P|è’.r
00D0 B0 01 E8 AC 00 72 16 8B - FB B9 0B 00 BE E6 7D F3 °.è¬.r‹ û¹..¾Æ}ó
00E0 A6 75 0A 8D 7F 20 B9 0B - 00 F3 A6 74 18 BE 9E 7D ¦u. ¹. .ó¦t¾ž}
00F0 E8 5F 00 33 C0 CD 16 5E - 1F 8F 04 8F 44 02 CD 19 è_.3ÀÍ^ .D.Í
0100 58 58 58 EB E8 8B 47 1A - 48 48 8A 1E 0D 7C 32 FF XXXëè‹G HHŠ.|2ÿ
0110 F7 E3 03 06 49 7C 13 16 - 4B 7C BB 00 07 B9 03 00 ÷Ã..I| K|»..¹..
0120 50 52 51 E8 3A 00 72 D8 - B0 01 E8 54 00 59 5A 58 PRQè:.rø °.èT.YZX
0130 72 BB 05 01 00 83 D2 00 - 03 1E 0B 7C E2 E2 8A 2E r»...ƒÒ. ..|ââŠ.
0140 15 7C 8A 16 24 7C 8B 1E - 49 7C A1 4B 7C EA 00 00 |Š$|‹ I|¡K|ê..
0150 70 00 AC 0A C0 74 29 B4 - 0E BB 07 00 CD 10 EB F2 p.¬.Àt)´ »..ÍëÒ
0160 3B 16 18 7C 73 19 F7 36 - 18 7C FE C2 88 16 4F 7C ;|s÷6 |þâˆO|
0170 33 D2 F7 36 1A 7C 88 16 - 25 7C A3 4D 7C F8 C3 F9 3Ò÷6|ˆ %|£M|øÃù
0180 C3 B4 02 8B 16 4D 7C B1 - 06 D2 E6 0A 36 4F 7C 8B ô.‹M|± .ÒÆ.6O|‹
0190 CA 86 E9 8A 16 24 7C 8A - 36 25 7C CD 13 C3 0D 0A ê†éŠ$|Š 6%|ÍÃ..
01A0 4E 6F 6E 2D 53 79 73 74 - 65 6D 20 64 69 73 6B 20 Non-Syst em disk
01B0 6F 72 20 64 69 73 6B 20 - 65 72 72 6F 72 0D 0A 52 or disk error..R
01C0 65 70 6C 61 63 65 20 61 - 6E 64 20 70 72 65 73 73 eplace a nd press
01D0 20 61 6E 79 20 6B 65 79 - 20 77 68 65 6E 20 72 65 any key when re
01E0 61 64 79 0D 0A 00 49 4F - 20 20 20 20 20 20 53 59 ady...IO SY
01F0 53 4D 53 44 4F 53 20 20 - 20 53 59 53 00 00 55 AA SMSDOS SYS..Uª

[Wonko the Sane]

So, it's an issue with your "updated" code.

Why could you not zip the files and post them instead of a hex view?

What happens if you:

• fdisk/format the disk with DOS 6.22
  
• leave alone the root directory
  
• only replace the bootsector CODE (and NOT the BPB) in the PBR with your own modifications

What if you replace the whole bootsector (both code and BPB)?


Wonko


P.S.: Hold your horses:
There is an issue in the BPB:
WORKING (made from HDD IMAGE under an emulator and copies to USB drive)
Offset 0x16 C700 (Sectors per FAT:199)

RMPrepUSB formatted - Not Working
Offset 0x16 0001 (Sectors per FAT:256)

Modified RMPrepUSb - still hangs at Starting MS-DOS if IO.SYS is first in root folder, followed by MS-DOS etc.
Offset 0x16 0001 (Sectors per FAT:256)