MacBook Pro 2,2 Boot loader shows GRUB. What's that?

[DeadlineX]

Hi, folks!
I have MacBook Pro late 2006 (MACBOOK2,2) 15" 2,16 GHz. I had working Win7x64 installation on it unless I've tried to install Ubuntu into another partition, where Mac OS X 10.5 was located. Ubuntu installer killed my Win7 installation, though partition itself was not damaged. A message "Missing operating system" appears, when I try to select "Windows" icon in the Boot Manager.
Then I've tried to repair it with Linux gdisk utility, recreating the hybrid MBR. MBR was created, but gdisk assigned incorrect boundary for the very first EFI partition in the hybrid MBR, so now I see some new situation:
- Ubuntu is still running OK
- Win7 partition can be mounted within Linux OS
- a lot of lines appear when I select "Windows" drive icon in the Boot Manager, finished by "Press any key to command line mode". I press and "GRUB>" prompt appears. And this is definitely NOT the GRUB from Linux partition or EFI partition. It has different command set and (as I suspect) works in the CPU real mode, like DOS.
What is this GRUB? Any documentation? Any config file syntax? Whatever else? I can't find any info around the Net

The only thing I've discovered occasionally pressing Esc key, is that Boot menu appears (which was never seen before) with few items as
"Windows 7 / Vista / Server"
"Windows 7 / Vista / Server (no SLIC)"
"Debug (default)"
"Debug (legacy)"
"Windows NT / 2000 / XP"
"Loader help"
None of them work but "Loader help", which shows GRUB commands list, though it shows it so ugly, with lines truncated, so I can't see the right syntax. And there is no help on these commands (what they do, how to use them, etc.)
What is this loader? Is there any key combination to switch to this screen on normal power on?

I can provide screenshots if it's necessary.

Thank you.

 

[wicknix]

What is this GRUB?

It's a boot loader. Hopefully this will get you going in the right direction. GRUB bootloader - Full tutorial

 

[DeadlineX]

Hopefully this will get you going in the right direction.

Thank you for the prompt reply. The only what's unclear for me, is WHERE is it located? I mean the GRUB itself? Is it inside firmware? And where is expects to see its config file? Obviously, my HDD hybrid MBR is malformed now, but if I'll get it working, then where to seek? I never saw anything like GRUB.CFG related to this GRUB, on my HDD, when I looked at EFI GPT partition from Linux OS. The only, what I can see there, is /EFI/APPLE/xxxxx/ and firmware file inside. So, where is it?

 

[bobesch]

Thank you for the prompt reply. The only what's unclear for me, is WHERE is it located? I mean the GRUB itself? Is it inside firmware? And where is expects to see its config file? Obviously, my HDD hybrid MBR is malformed now, but if I'll get it working, then where to seek? I never saw anything like GRUB.CFG related to this GRUB, on my HDD, when I looked at EFI GPT partition from Linux OS. The only, what I can see there, is /EFI/APPLE/xxxxx/ and firmware file inside. So, where is it?

Ah, that's the main reason I stayed away from installing Linux on a second partition in addition to Windows or macOS, because Linux highjacks with grub the booting-process somehow.
I am looking for an answer to your question too, how to remove grub and return to the previous booting-manager, that came with either macOS or Windows ...

If there's no better solution I'd use a second harddrive for a recovery with bootable PartitionWizardFree 9. That recovery-harddrive needs to be swapped in to replace your current impaired internal drive first, which then will stay out of harms way.
Then follow the next steps either for a macOS/Win-DualBoot option or a Win-SingleBoot-Option without macOS
a) if you want to return to the macOS + Win dual boot option: start the usual macOS installation followed by the BootCamp-assistant procedure and install the same Windows-version, that is on your currently corrupted harddrive with the original Windows-partition.
b) if you want just Windows on your Mac, then preformat the new harddrive with MBR (MasterBootRecord) partition-table. You can use either the Ubuntu-live-CD with gparted for that (ust msdos partition-table) or the bootable PartitonWizardFree9. Then install your Windows-version onto that empty drive with MBR-partition table.
Once you've finished step-1 or step-2, you'll have fresh Windows-installatoin, either as single or as macOS/Win dual-boot option.
Now you'll have to clone your original Windows-partion to the Windows-partition of the new harddrive. It's important, that the size of the new Windows-partition matches the size of your data on the previously created windows-partition on the new drive.
For the cloning process, the Mac has to be booted from the PartitionMagicFree9-live CD (it's basicly a tiny bootable Linux with the virtualized PartitionMagicFree9-application) and your old original drive has to be connected via USB.
Once PartitionWizard is running choose to option to clone just your original windows-partition to the windows-partition of your new harddrive (not the migration of the whole system, because then you will probably copy the grub-bootmanager too)
Take care, not to mix up the cloning direction, because otherwise your original data get lost (to reassure, plug-in & out the USB-connection of your original drive and refresh the display within PartitionWizard to be sure, which disk is the original-drive and which will be the target for cloning).
I've used PW to migrate a Windows-install from on drive/BootCamp-Mac/WinPC to another drive/BootCamp-Mac/WinPC several times without any problems, but I don't know, if just cloning the windows partition will keep the new drive bootable too.
The second problem might be, that your Windows-activation will get lost after that procedure, at least if you run an Win10, that was upgraded from Win7/8.
Unless things gets mixed up accidentally and PartitionWizard was falsly configurated to override the original Windows, otherwise the original drive is not touched by that procedure.
If there is no more sophisticated way to remove 'grub' and reinstall the windows-booting function, the above mentioned procedure would be my way to try to get the problem sorted out.
Cheers and good luck!

PS: there are other bootloaders, that might replace grub and recover the dual-boot-functionality. Maybe someone here knows more about that. You may ask @Hughmac about an alternative bootloader (e.g. rEFInd) and if it's possible, to replace grub by it - he posted infos/pictures about that here: https://forums.macrumors.com/threads/the-linux-thread-for-early-intels.2305943/post-30134921
To be honest: if your original-Windows installation holds important data or a lot of effort of configuration/installation I'd take a second-drive too and use PartitionWizard for a full disk-clone (the migrate harddrive to SSD option) and try out things on the clone-drive first!

 

[bobesch]

It's a boot loader. Hopefully this will get you going in the right direction. GRUB bootloader - Full tutorial

That pages seem to deal more with Linux-centric troubleshooting ... or maybe I'm a bit short of sight and didn't find a topic about how to recover the previously replaced Windows-bootloader?

(Actually I encountered that grub-problem more than a decade ago too after DualBoot-installation side-by-side to WinXP. At that time I was even more a novice than I am now and after I had no clue, how to get back to a single Windows install I then reinstalled Windows from the scratch and never dared to try a DualBoot installation with Linux again, but only chose to try Linux within virtual machines ...)

Edit: found a link to https://www.supergrubdisk.org/ on that grub-tutorial page. Wow, that looks promising!

 

[DeadlineX]

Edit: found a link to https://www.supergrubdisk.org/ on that grub-tutorial page. Wow, that looks promising!

Screens look promising, but it doesn't work I need to use "safe mode" because of Radeon X1600, and what I get is shown on the screenshot attached.

If there's no better solution I'd use a second hard drive...

It's quite obvious solution, but I don't like the idea to reinstall Windows from scratch. And I need just this partitions scheme as I have now: Linux/Windows without MacOS. I need Windows just as "backup system" because it works extremely slowly with 3 GB RAM.

 

[DeadlineX]

I tried similar tool called Ventoy from https://www.ventoy.net/en/index.html It doesn't work for me at all. No matter what ISO I put there as well as what platform (x86 / x64). I even tried to put the same Ubuntu ISO, as I've already installed to HDD. Just black screen and nothing more... I tried to add plugins - no effect. And no diagnostics, so I even couldn't investigate the problem.
So, I'm starting to think about DVD drive reanimation... So sad story

 

[DeadlineX]

t's a boot loader. Hopefully this will get you going in the right direction. GRUB bootloader - Full tutorial

I just wonder, there is "command [FILE] among this boot loader commands. But it's not described in the tutorial above. I get message "Invalid executable format" when I try to use any executable path with this command. So, do you know what is the [FILE]?

 

[wicknix]

Wish i could say yes, i know, but i don't. I dislike grub. If it breaks, i have no idea how to fix it. It's like Vi/Vim and Emacs. Too complicated for my abused brain. I also don't like that it's the default for 99% of every Linux distro in existence even though multiple other boot loaders exist. I spend the majority of my Linux life on PowerPC's which mainly use yaboot, or at least have the option to choose yaboot instead of grub. Hopefully somebody well versed with grub will chime in as i haven't the slightest.

Cheers

 

[NewbiePPC]

Hi, maybe you can try boot-repair, sometimes when I has problems with grub that fixed. I know that isn't your problem but maybe you can start windows from grub.

You have to boot from ubuntu - debian live sesion, add the repository and install it. Its simple and it save me some hours before, wish it helps!

 

[bobesch]

It's quite obvious solution, but I don't like the idea to reinstall Windows from scratch. And I need just this partitions scheme as I have now: Linux/Windows without MacOS. I need Windows just as "backup system" because it works extremely slowly with 3 GB RAM.

Sometimes there's no sophisticated way to solve a problem and searching for such a thing is more time consuming, than starting from the scratch ...
Since you (and me too) have to tinker with a Linux/Windows-Combo in order to make everything work as wanted, you better need to try that with a fresh install of Linux and Windows7 on a new SSD. Once everything (especially the booting) works fine, you can just clone your precious Windows7-partition to the newly prepared Windows7-partition using PartionWizard or something else like that.