[SOLVED] BIOS not seeing OS/boot loader

Questions about Grub, the liveCD and the installer
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Fuzzy
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[SOLVED] BIOS not seeing OS/boot loader

Post by Fuzzy »

Background (I wanted to test a couple things I haven't done before):

1. I installed a new drive.
2. Trying something new, I set the drive to gpt
3. I used gparted to copy a Windows partition, a Windows Boot partition, a SWAP partition, and my /home partition onto the new drive.
4. I then installed Cindy onto the / partition

Upon reboot, the BIOS doesn't see an OS/boot loader.

5. I booted from the Livecd again and (via gparted) checked the managed flags for my old drive and changed the new drive's flags to match.

Upon reboot the BIOS didn't see an OS/boot loader.

6. I booted from the Livecd again and used chroot to mount the installed filesystem.
7. I then ran grub-update.
8. It found and listed all the correct OS installations.

At reboot, the BIOS still doesn't see an OS/boot loader.

Perhaps I've entered too many variables into this new install. Is the gpt the problem, or is there something else I could do to get this current configuration running?

Thanks!
Fuzzy
Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 2 times in total.
Reason: Topic automatically closed 6 months after creation. New replies are no longer allowed.
gm10

Re: BIOS not seeing OS/boot loader

Post by gm10 »

This is all a bit abstract. Post output of

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inxi -Fxz
and of

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lsblk -f
please so we know what you are working with.
rene
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Re: BIOS not seeing OS/boot loader

Post by rene »

I take it the machine itself is BIOS-only or at least set to boot in Legacy mode. GRUB on an MBR-partitioned disk embeds itself between the MBR itself (i.e., the very first 512-byte sector) and the start of the first partition. Both historically with said start at sector 63 and certainly with it these days at sector 2048, 1MiB, it has enough room to do so. On a GPT-partitioned disk however it needs a more well-defined place to embed itself, seeing as how the GPT table itself takes up (more) of that formerly available space; needs a "bios_grub" partition, a "BIOS boot partition": https://en.wikipedia.org/wiki/BIOS_boot_partition.

The Arch Linux Wiki is possibly a fairly nice reference: https://wiki.archlinux.org/index.php/GR ... structions

Seeing as how you already installed things at this point, do be sure to note that sector 34-2047 advise: you can still insert that partition now, although you do of course need to make sure to reinstall grub so that it in fact also gets used.
Fuzzy
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Re: BIOS not seeing OS/boot loader

Post by Fuzzy »

Thanks for the links!

Yeah, as soon as I posted, I realized that I hadn't double-checked the "BIOS" to make sure UEFI was enabled. It wasn't. So, I enabled it.

Then, I created a new partition at the beginning of the drive, and flagged it as "bios_grub"

I then re-installed Cindy.

After installation, the EFI / grub64.efi file structure appeared on the "bios_grub" partition, but the system still won't see it as a bootable drive.

I might be close, and I might not be. I'm tempted to wait till tomorrow and just wipe everything and start from scratch again. I'm trying to learn a few things, so I'd like to stick this out if I can.

Thanks again for the help.
Fuzzy
gm10

Re: BIOS not seeing OS/boot loader

Post by gm10 »

The EFI partition needs to be flagged boot and esp, not bios_grub.
rene
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Re: BIOS not seeing OS/boot loader

Post by rene »

... and alternatively, then, keep UEFI disabled and do install grub on the bios_grub partition (which happens automatically if you in the installer just pick "/dev/sdz", for "z" the proper "z"). But UEFI is nicer.
Fuzzy
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Re: BIOS not seeing OS/boot loader

Post by Fuzzy »

Sigh. I appreciate the great help everyone has given, but I'm missing something obvious.

If I wipe everything and create a new gpt partition table, and I have UEFI disabled.
I'm confused by which flags need to be on which partitions.

On the flip side of that - if I wipe everything and create a new gpt partition table on a UEFI enabled system.
I'm confused by which flags need to be on which partitions.

I've read through the links provided, but get confused by the wording - they talk so much about MBR comparing it to GPT, that I start getting lost when they throw around various partition flags - I'm not always able to follow which partition table type they're talking about at that time.

As a result, I'm still unclear of where/if to use the bios_grub flag. I'm also still unclear what role UEFI has (if any) in determining which flags to set on which partitions. I think I've tried just about every combination now, and still haven't figured out what I'm missing.

Any additional info or links you might provide would be greatly appreciated.

Thanks,
Fuzzy
kukamuumuka

Re: BIOS not seeing OS/boot loader

Post by kukamuumuka »

Fuzzy wrote: Wed Sep 12, 2018 1:52 pm If I wipe everything and create a new gpt partition table, and I have UEFI disabled.
I'm confused by which flags need to be on which partitions.

On the flip side of that - if I wipe everything and create a new gpt partition table on a UEFI enabled system.
I'm confused by which flags need to be on which partitions.
If UEFI is disabled, you need a small bios_grub partition.
If UEFI is enabled, you need a Fat32 EFI (esp) partition, and install grub into that partition.
gm10

Re: BIOS not seeing OS/boot loader

Post by gm10 »

Fuzzy wrote: Wed Sep 12, 2018 1:52 pm On the flip side of that - if I wipe everything and create a new gpt partition table on a UEFI enabled system.
I'm confused by which flags need to be on which partitions.
Only this:
gm10 wrote: Tue Sep 11, 2018 4:17 pm The EFI partition needs to be flagged boot and esp
That partition needs to be formatted with a FAT file system.

And unless this is a learning exercise you could also just let the installer create these for you in automatic mode.
Fuzzy
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Re: BIOS not seeing OS/boot loader

Post by Fuzzy »

Thanks to both of you for the clarifications.

I started from scratch as indicated below, but still didn't have success. Cound it be my BIOS/UEFI?

The system is currently set to use UEFI.
I booted off a liveUSB.
I started the Cindy Installation.
I created a FAT32 100M partition at the beginning of my hard drive (drive is /dev/sda, and this partition is /dev/sda1). I flagged this fat32 partition as boot,esp.
I created a swap partition.
I created a /home partition and assigned it during installation.
I created a / partition and assigned it during installation.
When the "Install GRUB (to where)" option displayed, I selected to install GRUB to /dev/sda1.

The installation completed, but the system wouldn't see the hard drive as a valid boot device at reboot.

I booted back into the system using a liveUSB and looked at the partitions.

For some reason, the installation had automatically flagged the / partition as bios_grub. I removed the flag and rebooted, but still had no success.

Did I do something wrong?
Fuzzy
gm10

Re: BIOS not seeing OS/boot loader

Post by gm10 »

Fuzzy wrote: Wed Sep 12, 2018 4:53 pm For some reason, the installation had automatically flagged the / partition as bios_grub. I removed the flag and rebooted, but still had no success.
Are you sure that you had booted the USB in EFI mode? If this produces no error when you run this from the live USB then you did:

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ls -d /sys/firmware/efi/
If yes, then other possibility is that you need to disable secure boot and potentially TPM in the UEFI BIOS.
Fuzzy
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Re: BIOS not seeing OS/boot loader

Post by Fuzzy »

I believe my problem with UEFI is, indeed, something wrong with my computer. I tried to update the standard BIOS, and it updated fine...but it only has one simple "enable/disable" option for UEFI. When enabled, I have the additional options of selecting UEFI boot priorities, but again, the installation adds a flag of bios_grub when I have enabled UEFI. (I'll have to shut my computer off and change out hardware before my next tests, and I'll run the suggest ls -d command at that point...but I have a feeling it will verify that the system isn't actually booting using UEFI)

There's a seperate (older) UEFI update, but it fails with a generic error when I try to apply it. When I searched the web for the generic error, it appears that this is a common issue with my computer.

So, if all this holds true, I'll start over using non-UEFI and see how things go.

Thanks for the help - I'll update the thread as things go further. If any Moderators read this and feel it is better suited to a different forum area, I understand. I think it is pretty obvious that Cindy has nothing to do with my problems at this point.

Thanks again - I am learning a lot...I'm just hopeful that I eventually get to the reward of learning new stuff and get it to work!
Fuzzy
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Re: BIOS not seeing OS/boot loader

Post by Fuzzy »

So...the mystery is solved (I think).

It appears that the UEFI on my system is old. In fact, it was deemed as "experimental, for developing purposes only" as well as "unstable" and other such descriptors.

So, after weighing all factors, I decided to just go the BIOS/MBR route and avoid GPT for this machine. I'll wipe another machine to test out my new understanding of GPT you all provided me.

Thanks for all the info, links, and explanations - especially since it didn't end up pertaining to Cindy at all.

As a side note: I was a little skeptical of moving to Cindy because of Cinnamon (I had tried Cinnamon a few years ago and hated it). However, Cinnamon has come a LONG way (or, perhaps my views have changed), and I've really enjoyed what I've seen of Cinnamon/Cindy so far. I'm excited to get things going now. Thanks again to all of you.

Fuzzy
rene
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Re: [SOLVED] BIOS not seeing OS/boot loader

Post by rene »

BIOS/GPT probably works fine. If you don't need more than 4 partitions, little point, and only a bit more if you do, but if you want to use GPT you should be able to. You'll as said just need to create the small bios_grub partition to in fact hold grub.
Fuzzy
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Re: [SOLVED] BIOS not seeing OS/boot loader

Post by Fuzzy »

Thanks Rene,

The final determining factor in my GPT/MBR decision ended up being: Since I couldn't do what I wanted with UEFI/GPT, I decided to dual-boot this system with Win, so that drove me to the MBR side of things.

Fuzzy
rene
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Re: [SOLVED] BIOS not seeing OS/boot loader

Post by rene »

Fair enough. Although I'm myself also back to MBR on all BIOS-only systems I still have running, allow me to add even if only for posterity that although Windows can not boot from a GPT partition on a BIOS system, Windows 7 and up are otherwise fine with GPT; I'm not mistaken, actually Vista SP1 and up. This means that on a these days again relatively standard multiple-drive system -- fast and small SSD plus slow and large HDD -- you can have say the SSD be MBR and host the small Windows boot partition with all the rest of Windows on the GPT HDD. Or, geekpoint extravaganza, even have a hybrid MBR/GPT system on one disk where you abuse the compatibility MBR of a GPT-disk to be not just compatibility but to have a with a GPT partition entry coinciding MBR-entry for the Windows boot partition. Or...

Never mind. I once thought that stuff quite fascinating but indeed it in fact isn't. If MBR will do, it will do...
gm10

Re: [SOLVED] BIOS not seeing OS/boot loader

Post by gm10 »

I'll just add that if you had actually done what I asked you in the first reply to this thread, i.e. give us your system information, then we probably would have figured this out right away. ;) Glad to see you found a solution/workaround though.
Fuzzy
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Re: [SOLVED] BIOS not seeing OS/boot loader

Post by Fuzzy »

gm10....Your point is well-taken. There is a reason I didn't get back to you with the data, but it's too convoluted to go into, and it's all water under the bridge at this point anyway. I certainly appreciate your help and good nature.

Fuzzy
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Re: [SOLVED] BIOS not seeing OS/boot loader

Post by lsemmens »

I'm glad your issue is solved. From past experience, UEFI is more trouble than it is worth. I generally disable it if I am not dual booting with Windwoes.
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gm10

Re: [SOLVED] BIOS not seeing OS/boot loader

Post by gm10 »

lsemmens wrote: Fri Sep 14, 2018 3:58 am I'm glad your issue is solved. From past experience, UEFI is more trouble than it is worth. I generally disable it if I am not dual booting with Windwoes.
From my experience, I haven't used anything but UEFI/GPT in any device that had an UEFI. There are some fringe cases like 32bit UEFIs or apparently that early development version OP had here, but otherwise it's so much better than BIOS/MBR, I'd never go back.
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