82 replies to this topic

[ireneuszp]

New version http://nufans.net/gr...-2009-04-30.zip
http://nufans.net/grub4dos/

[vmbray]

Hi, thanks a lot for your great work on grub4dos, it's a big help to me.

I wonder if there's any help for the 'missing mbr helper' I get on certain of my *crappy* motherboards. I've found that formatting with hp util and installing grub4dos works on them, but formatting with the more compatible make_usb_2 and installing grub4dos causes the error. Very interestingly, copying the mbr sector from the hp format to the make_usb_2 format will cause it to work, but breaks it for other mobo.

I could document this for you in detail if there's any point, don't know if there is any help for it or not but just thought I'd throw it out there. Thanks!

[tinybit]

Try the triple mbr please. There are 4 triple-mbr images in http://nufans.net/grub4dos/images/

They are mbrgrldr.img.gz, mbrgrldr_8gb.img.gz, mbrgrldrnobpb.img.gz and mbrgrldrnobpb_8gb.img.gz.

You should decompress them before write to the USB.

Use dd(for windows/linux) or similar tool to write an image on to your USB drive. Obviously this will erase all your files on the USB drive, so you must backup your files before you overwrite it with one of the MBRGRLDR*.IMG images.

You may try first with mbrgrldrnobpb.img, then with mbrgrldr.img. If both would result in a bootable USB drive, you may try again with mbrgrldrnobpb_8gb or mbrgrldr_8gb.

[vmbray]

Thank you, that is very interesting indeed. I'm having a bit of a challenge with this but it does seem to work. It looks like the partition table is different from my flash size (testing with 256mb) so I'm getting drive not formatted, format it now? from windows. However, I was able to get the grub4dos menu with your first image.

I'm writing zeros to the ufd now, then going to format in windows and note in beeblebrox the partition info, then restore your image, then tweak the partition table in beeblebrox so maybe I can see the files.

Is there any way to write just the mbr like what I'm used to in grub4dos? Thanks again, that is very hopeful.

*edit - tried the other images too and it seems like all will boot, and all cause windows to offer to format my usb drive - but I bet you knew that Tried in beeblebrox to edit the partition table but since I really don't know what I'm doing this isn't working out. Last thing I tried is the mbrgrldr_8gb.img and it boots on all three of my machines I've been testing - will try others at work tomorrow, very cool! *

[tinybit]

The images mentioned above can all be booted either as a floppy (fd0) or as a harddrive (hd0). I mean each image can successfully boot in both cases. So it fits for whatever machines, in theory.

I opened mbrgrldr_8gb.img with hexedit under Linux(you may do this under Windows). Change the partition length(at offset 1CA) from C0 E4 EE to 40 6C 07. Save as mbrgrldr_256mb.img. At last, run the following bootlace.com command for 4 times:

The first run:

bootlace.com --serial-number=0x23456789 mbrgrldr_256mb.img

The output message is:

Triple MBR cancelled. Original partition layout restored.

The second run:

bootlace.com --serial-number=0x23456789 mbrgrldr_256mb.img

The output message is:

Success. Triple MBR installed.

The third run:

bootlace.com --serial-number=0x23456789 mbrgrldr_256mb.img

The output message is:

Disk geometry calculated according to the partition table:

Sectors per track = 63, Number of heads = 255

Triple MBR cancelled. Original partition layout restored.

The fourth run:

bootlace.com --serial-number=0x23456789 mbrgrldr_256mb.img

The output message is:

Disk geometry calculated according to the partition table:

Sectors per track = 63, Number of heads = 255

Success. Triple MBR installed.

Now this mbrgrldr_256mb.img is ok for your use.

I uploaded the image(for the 256MB USB drives) to http://nufans.net/grub4dos/images/

If Windows asks you whether to format the USB drive, you may say "Yes, please!"

[vmbray]

tinybit, thank you for trying to help me, I'm not sure I'm getting it but I'm trying. The 256 image doesn't work for me, explorer tells me to 'insert a disk' apparently it's seeing it as a floppy or some such. When I format in disk mgmt it won't boot any more. Two things I'd like to figure out, one, will this work on my trouble machine which I thought I tried last night with success but now I just have done so much I'm confused (and not working see attached picture) and two, to build this from scratch so I can maybe understand how the partition table is supposed to look, I can't understand how it's laid out. I think it's due to the first partition being so small that it confuses me, but I can't adjust the table in beeblebrox and get windows to like it. That seems to be the cause of the trouble machine's unhappiness, since it sees hd0,1 as a non-MS partition.

I loaded up ubuntu in a vm to try to do this from scratch where I'm confused about how to fdisk - I see where you helped someone else but it still doesn't make sense.

1. could you give me a linux command to fdisk as an example?
2. do I just create one partition or two? where does the second one get created?

Sorry I'm such a pest and thanks again for trying to help!

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[vmbray]

I was able to use linux to fdisk. I'm a bit confused as to which sector exactly to start with but I did something like this:

fdisk -u /dev/sdb (-u to get into sector mode right?)
n to create
p for primary
partition number 1
first sector 95
last sector 2779??? that would give me 0 to 2779 = 2880 sectors of total disk used, which seems like it would make sense with the floppy emu part of this.

so that seemed okay since I was then able to use bootlace to install the mbr and it told me 'triple mbr installed'.

now I'm puzzling with the part using dd to get just the first 96 sectors, I'm getting huge output files which I'm sure is the syntax. As a side question it seems like here it would make more sense if I was trying to get the first 95 sectors, or 0 to 94 since that is the area before the partition and would not include the first sector of the new partition. Or maybe we want the first sector of the partition?

My stick is now looking for grldr and not finding it, and also I cannot format the partition in windows, offers to but then gives an error that it couldn't (it's fat 12).

I just wanted to give you an update of where I am so you don't waste time answering an earlier question, thanks again!

[was_jaclaz]

vmbray,
looky here:
http://www.boot-land...?...ic=7932&hl=

jaclaz