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#1 gbrao

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Posted 09 March 2009 - 05:04 PM

Hi,
I've just started using grub4dos, thanks for this excellent tutorial. Just made a bootable USB drive with a lot of useful stuff.

I would like to now like to multiboot the OSs on my harddisk. I have two doubts :

1) Since Vista uses the MBR disk signature, please let me know if grubinst/bootlace overwrite the disk signature when installing grub4dos to the MBR. That is, after using grubinst, will the disk signature be preserved.

2) If grldr and menu.lst are on a partition that is hidden, will grub4dos still find them ?

Thanks.

PS : Thought this info could be included in the guide, that's why I'm posting here. Newbs like me might have the same doubts.

#2 was_jaclaz

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Posted 09 March 2009 - 05:54 PM

Actually not really "newbie" kind of questions :cheers:, real "newbies" tend to ask more things like:

I want to boot Vista, Ubuntu, Ghost, puppylinux Server 2003, BartPe, this and that. Any hints?

:cheers:


Hopefully two answers:
1) NO it is NOT overwritten, meaning YES, disk signature is preserved. (for the record ANY NT based OS uses Disk Signature, inclufding NT 3.51, 4.00, Win2k, XP and Serever 2003, besides Vista, Server 2008 and Windows 7)
2) YES, grub4dos grldr.mbr scans all partitions, including hidden ones, this is done in hard disk order, thus, (hd0,0) will be faster than, say, (hd12,18) :cheers: you must be aware of this if you have multiple instances of grldr/menu.lst.....

Something (a bit more advanced) that might interest you, on the topic of hiding/unhiding partitions and related:
http://www.boot-land...?showtopic=7138

As well, something that might interest you about where menu.lst is searched:
http://www.boot-land...?showtopic=6775

:cheers:

jaclaz

#3 gbrao

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Posted 10 March 2009 - 05:39 AM

Some more not-so-newbie questions :
1) When using grub4dos (MBR) does it matter if the menu.lst file is in Unix or DOS format ? Most of the menu.lst files I come across are in Unix format.
2) When using grub.exe ( DOS partition ) does it matter if the menu.lst file is in Unix or DOS format ?
3) In either case what about file/path names in menu.lst? That is, the forward-slash backward-slash etc. problem.

Asking this because when I was making my bootable USB drive with Parted Magic (grub4dos ver), I first started out with a DOS bootable FAT32 USB drive. After booting to DOS and running grub.exe, it just would not work. When I made the USB drive bootable with grub4dos, it worked OK.

#4 was_jaclaz

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Posted 10 March 2009 - 02:47 PM

1) NO
2) Should not, but untested, source of grub.exe and grldr is the same, however I personally always use "DOS" format with CR+LF
3) ONLY forward slash / for paths

The error you got was probably due to an alltogether different problem, which is the way "normal" MBR and bootsector may work (or fail to) with FAT32.

jaclaz

#5 gbrao

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Posted 16 March 2009 - 06:53 AM

Could the guide also please include this info :

Assume grub4dos MBR is installed to a removable device ( CD or USB thumb drive ). It is now possible to boot from this device on any computer.

From where will grldr ( and menu.lst ) be loaded ? The computer may have grldr and menu.lst files too ( on a hdd for eg. ).

Is it possible to select the grldr and menu.lst files on the removable device ? That's what we would want, right ?

#6 was_jaclaz

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Posted 16 March 2009 - 07:55 AM

Could the guide also please include this info :

Assume grub4dos MBR is installed to a removable device ( CD or USB thumb drive ). It is now possible to boot from this device on any computer.

From where will grldr ( and menu.lst ) be loaded ? The computer may have grldr and menu.lst files too ( on a hdd for eg. ).

Is it possible to select the grldr and menu.lst files on the removable device ? That's what we would want, right ?


Normally it will work.

When booting grub4dos grldr will first thing search for menu.lst on the currently root device (i.e. the one which it was booted from).

To make sure, you can change the filename of the menu.lst in the "embedded" .lst file in the copy of grldr on the CD or USB device, see here:
http://www.boot-land...?...=7231&st=25
http://www.boot-land...?showtopic=6775
http://www.boot-land...?...c=6775&st=5

Or use a "tag" file to "link" to a given volume:
http://www.boot-land...?showtopic=4799

Here is a more elaborate example:
http://www.boot-land...?showtopic=5409

Or use the uuid command to "link" as well to a given volume:
http://www.boot-land...?...=7231&st=27

jaclaz

#7 gbrao

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Posted 17 March 2009 - 04:55 AM

Sorry, it's me again. Using the guide to make a grub4dos boot CD with "mkisofs -R -b grldr -no-emul-boot -boot-load-size 4 -o grldr.iso iso_root".

1) While creating the ISO I get messages like : "Using AUTOR000.CMD;1 for iso_root/I386/SYSTEM32/AUTORUN0XPE.CMD (AUTORUN0PEWSH.CMD)
".
2) When I mount the ISO using Daemon Tools, file & directory names are in 8.3 uppercase format. Eg. directory "everything" is "EVERYTHI".

3) When I view the ISO using ISOBuster, in the left pane it is "EVERYTHI", while in the right pane it is "everything".

Is this OK ? Or is there some sort of restriction for file/directory names ?

Edit : Got the answer at http://www.itg.uiuc....ofs/mkisofs.htm .

#8 was_jaclaz

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Posted 17 March 2009 - 08:33 AM

That mkisofs command is for a "plain" grub4dos CD, you need additional settings for the "other" thing(s) you are putting on it (a PE of some kind), check the lines here:
http://www.911cd.net...o...18045&st=25

it should be allright to change
-boot-load-seg 0x1000
to
-boot-load-size 4

jaclaz

#9 gbrao

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Posted 19 March 2009 - 08:03 AM

Could the guide please clarify this : The guide and readme for grub4dos suggests that the grub4dos MBR could come from any of these - grldr.mbr, grldr 4 sectors, grldr, bootlace, grubinst. What is the difference ? Bit confused because the first 4 sectors of grldr and grldr.mbr are not identical.

When using a Windows ISO tool like UltraISO to create a grub4dos bootable CD, what should one specify as the boot file ?


#10 was_jaclaz

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Posted 19 March 2009 - 01:05 PM

Could the guide please clarify this : The guide and readme for grub4dos suggests that the grub4dos MBR could come from any of these - grldr.mbr, grldr 4 sectors, grldr, bootlace, grubinst. What is the difference ? Bit confused because the first 4 sectors of grldr and grldr.mbr are not identical.

When using a Windows ISO tool like UltraISO to create a grub4dos bootable CD, what should one specify as the boot file ?


Cannot really say where you got that info. :good:

However:

On bootable CD, use grldr (NOT grldr.mbr, NOT bootlace, NOT grubinst) as no-emulation bootsector.

To clarify:
  • grldr.mbr is EXCLUSIVELY a Hard Disk kind of MBR (on Hard Disk ONLY)
  • bootlace is EXCLUSIVELY the DOS or Linux install program for grld.mbr (on Hard Disk ONLY)
  • grubinstall is EXCLUSIVELY the DOS or Linux install program for grld.mbr (on Hard Disk ONLY)

The "4 sectors" are probably referred to the mkisofs command option "-boot-load-size 4" which means more or less:
"no matter how big is the boot file (grldr ^_^) when booting consider only the first 4 sectors as the actual no-emulation boot record.

This is sometimes needed as some BIOSes may find that the whole boot file (grldr ^_^), loaded with option "-boot-load-seg 0x1000" is not 2048 bytes long, as a normal CD no-emulation bootsector is.

jaclaz

#11 gbrao

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Posted 19 March 2009 - 02:00 PM

OK, thanks, I was confused.

Please let me know what 'boot file' I would use with a program like UltraISO.

With relatively modern PCs, the "-boot-load-seg 0x1000" method would be preferable to the "-boot-load-size 4" ?

#12 was_jaclaz

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Posted 19 March 2009 - 02:10 PM

I splitted the topic as it seemed to me getting "out of scope" of the original Guide sticky.

If you use mkisofs you use grldr as boot file.
If you use ANY other program, you use grldr as boot file.

Try yourself whether you have better results with any of the two:
"-boot-load-seg 0x1000" method would be preferable to the "-boot-load-size 4"
(of course this does not apply if use ANYTHING BUT mkisofs) :good:

As said:
http://grub4dos.sour..._bootable_CDROM

jaclaz

#13 gbrao

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Posted 21 March 2009 - 01:30 PM

I created a grub4dos bootable CD using UltraISO ( grldr as boot file ). I get an error "Warning! Invalid first FAT entry (=0x0) !". I transferred all the files from the CD to a grub4dos bootable USB thumb drive and it worked fine. So the error is due to the way I created the ISO or with my CD drive. I copied the messages from grub4dos during boot up :

get upper memory

hard drives : 1, int13: ...

getdisk_info(80) , ... (some error about 1 less sector )

.

.

bootdrive=EF, int13/4B01(EF),err=0,drive=EF, Is CD

cdromdrive=EF

starting cmain() ... Open/default ... [b]failure[/b].

No PXE stack.

.

End of menu init commands. Press any key to enter commandline ...

.

grub>root

  (hd111):file type is iso9660, using whole disk

grub>find

  (hd0,0) (hd0,1) ... (cd)(fd0)

grub>root (cd)

grub> find /menu.lst

Warning ! Invalid first FAT entry (=0x0)

Please let me know what's gone wrong.

#14 was_jaclaz

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Posted 21 March 2009 - 02:00 PM

Use mkisofs first.

I don't use (and don't want to use) Ultraiso, probably you used some incorrect option, who knows?

You should post questions/problems about a Commercial app on their Forum:
http://www.ezbsystem...n/ikonboard.cgi

Possibly this helps: :good:
http://www.ezbsystem...r...=2195;

jaclaz

#15 gbrao

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Posted 02 April 2009 - 04:57 AM

@ jaclaz,

Thanks for the clear explanation given in Post #6 here :
http://www.boot-land...showtopic=7587#

Could you please also explain to us noobs why in the guide, sometimes there is a "rootnoverify" after the "chainloader".

#16 was_jaclaz

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Posted 02 April 2009 - 09:47 AM

Could you please also explain to us noobs why in the guide, sometimes there is a "rootnoverify" after the "chainloader".


It's indifferent whether it comes before or after the chainloader command, since everything happens after a boot command is given (or the implied one if from a menu.lst entry).

Since rootnoverify does not attempt to access the device/partition/volume, it cannot be used to "explore" it and chainload directly a file (unless the target is a known bootsector/filesystem, in which case one should use the root command, or to say it better, the access to the filesystem is given BECAUSE you could use a root command instead of the rootnoverify one).

But even if you use the root command, as long as you don't use "relative paths" to chainload a file or do not chainload a file at all, you can put it after the chainloader command.

To clear the thing, all of these should work the same:

title A ms-dos floppy
map (hd0,0)/dosfloppy.img (fd0)
map --hook
chainloader (fd0) +1
root (fd0)


title A ms-dos floppy
map (hd0,0)/dosfloppy.img (fd0)
map --hook
root (fd0)
chainloader (fd0) +1


title A ms-dos floppy
map (hd0,0)/dosfloppy.img (fd0)
map --hook
chainloader (fd0) +1
rootnoverify (fd0)


title A ms-dos floppy
map (hd0,0)/dosfloppy.img (fd0)
map --hook
rootnoverify (fd0)
chainloader (fd0) +1


But these need a root before:

title A ms-dos floppy
map (hd0,0)/dosfloppy.img (fd0)
map --hook
root (fd0)
chainloader +1


title A ms-dos floppy
map (hd0,0)/dosfloppy.img (fd0)
map --hook
root (fd0)
chainloader /io.sys


while these do not:

title A ms-dos floppy
map (hd0,0)/dosfloppy.img (fd0)
map --hook
chainloader (fd0)/io.sys
root (fd0)


title A ms-dos floppy
map (hd0,0)/dosfloppy.img (fd0)
map --hook
chainloader (fd0)/io.sys
rootnoverify (fd0)



:good:

jaclaz

#17 gbrao

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Posted 02 April 2009 - 01:01 PM

Thanks, again. grub4dos is such a great product, pity the developers do not provide adequate documentation with proper examples. For noobs that is.

If is wasn't for you and diddy, we may have never been able to use it.

Definitely needs to be 'marketed' better too. Many people haven't even heard of it.

Pushing my luck ... could you please explain :

... (or the implied one if from a menu.lst entry).


If there are no more commands before the next title command, implies "boot" ?

#18 was_jaclaz

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Posted 02 April 2009 - 03:34 PM

If there are no more commands before the next title command, implies "boot" ?


Exactly! :good:

Definitely needs to be 'marketed' better too. Many people haven't even heard of it.


Yep, ^_^, this is a "general" problem with many Freeware/Open Source project, programmers know how to program but usually simply cannot explain what they do in a manner that is comprehensible by "outsiders" or are simply too shy to "talk aloud", "noobs" are too "noobs" to understand them or their "unspoken truths".

The developers of grub4dos being mostly from China of course doesn't help much, on the Chinese fora there are often interesting reports/ideas that simply don't cross the language barrier.

Luckily there are around a bunch of guys like diddy or yours truly, that try to "translate" to the rest of the world some info, possibly in an intermediate form, and again luckily, there are a lot of other members that try to explain these things to an even more "accessible" level, writing small tutorials and also trying to help other members by publishing their reports of success or giving suggestions, and also by suggesting some "peculiar" uses that evolve into new features added to the app and or additional info.

All in all it is working better than expected, the amount of people getting interested in grub4dos and it's features is growing exponentially, what would be needed would be maybe some more "support" by Linux distro developers, if only some more could follow the example of what Patrick Verner did for parted magic:
http://www.boot-land...?...ic=6042&hl=

and Victor Chew did for UBCD:
http://www.boot-land...?...ic=7312&hl=
(thanks mainly to the good work by Icecube ^_^ )
and implement in their distro's compatible features with grub4dos capablities, grub4dos would surely "take off".

But also you are contributing, by posing interesting questions, you give an occasion to explain points that an already "expert" user (if I am allowed to define myself so ^_^) would otherwise take for granted.

From time to time diddy checks suggestions in the "Guide" thread:
http://www.boot-land...?showtopic=5187
and usually adds the info on next revision of the Guide.

So, if you think that some of the aspects discussed here may be of use for other members, try putting the info together and post them on that thread, I am sure diddy will consider adding them into the guide or as an Appendix of some kind.

^_^

jaclaz

#19 gbrao

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Posted 03 April 2009 - 03:27 AM

Should have mentioned this too in my previous post : grub4dos, boot-land and we noobs are really lucky to have you as a mod.

The best that I've come across. Thanks.

#20 was_jaclaz

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Posted 03 April 2009 - 11:41 AM

Should have mentioned this too in my previous post : grub4dos, boot-land and we noobs are really lucky to have you as a mod.

The best that I've come across. Thanks.


Choose one reply ^_^:

Reply #1 ("I Was Born Modest; Not All Over, But In Spots" - Mark Twain)
I really don't deserve all these compliments...^_^

Reply #2 (“Welcome those big, sticky, complicated problems. In them are your most powerful opportunities.” - Ralph Marston)
We try harder. ^_^

Reply #3 ("If chance will have me king, why, chance may crown me" - William Shakespeare)
What! ^_^, I am an Admin, NOT a simple Mod!
:good:


:)

^_^

jaclaz




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