GRUB2 in Slackware? Discussion and Instruction.

cwizardone · 08-12-2023, 12:57 PM

I've asked that the very informative grub related posts be moved here. Whether that happens or not, we'll see.

Edit in: This thread title reminds me of the old Berkeley Farms radio commercials. Berkeley Farms sold milk and other dairy products. Found a web site, but don't know if they are actually still in business.
As you may know, Berkeley, California is the home of the University of California, and is located in the urban San Francisco Bay Area.
Each radio commercial ended with the voice of Mel Blanc saying, "Farms in Berkeley?! Mooooo..."
Seems kind of dumb today, but it brings back a lot of memories.

Jeebizz · 08-12-2023, 01:06 PM

Is it going to be GRUB or GRUB2 ?

Emerson · 08-12-2023, 01:19 PM

May I express my opinion? No? Thought so.
Anyhow, GRUB(2) is the most pointless and useless piece of software for a distro like Slackware (or Gentoo). There are tens of megabytes of junk installed to the hard drive doing what ..? All this may be great for Ubuntu with automated kernel upgrades, but we are not running Ubuntu here.
Nowadays we have EFI boot and every mobo has boot menu. Install as many EFI stub kernels as you want and don't waste your time with a bootloader which is more like an OS. You can even multiboot using this mobo menu, you can have a bootloader(s) there for another OS which cannot boot directly from EFI as Linux does.
Or for gods sake, if you just must have a bootloader then Syslinux is absolutely great for legacy boot, LiLo is to be considered, too.

cwizardone · 08-12-2023, 01:20 PM

Quote:

Originally Posted by Jeebizz

Is it going to be GRUB or GRUB2 ?

It would have to be GRUB2.
I'll change the title.

Jeebizz · 08-12-2023, 01:22 PM

Quote:

Originally Posted by cwizardone

It would have to be GRUB2.
I'll change the title.

Fair enough but I guess I should also have clarified - as Pat alluded to switching to GRUB; so I assumed just GRUB as perhaps GRUB2 is too bleeding edge still for Slackware? I don't know.

volkerdi · 08-12-2023, 01:23 PM

Quote:

Originally Posted by Jeebizz

Is it going to be GRUB or GRUB2 ?

Obviously GRUB2.

Jeebizz · 08-12-2023, 01:24 PM

I'm going to post Luckycyborg's mini tutorial here as I think it is a good addition:

Quote:

Originally Posted by LuckyCyborg

Here's a mini-tutorial.

1. Setup the /etc/mkinitrd.conf

This config file wasn't invented by me, but by our BDFL and it's part of Slackware. You even have an /etc/mkinitrd.conf.sample on your system! ;p

So, first you should execute this command:

Code:

/usr/share/mkinitrd/mkinitrd_command_generator.sh -c

It will output something like:

Code:

SOURCE_TREE="/boot/initrd-tree"
CLEAR_TREE="1"
OUTPUT_IMAGE="/boot/initrd.gz"
KERNEL_VERSION="6.1.45"
KEYMAP="us"
MODULE_LIST="usb-storage:uas:xhci-hcd:xhci-pci:ohci-pci:ehci-pci:uhci-hcd:ehci-hcd:hid:usbhid:i2c-hid:hid_generic:hid-asus:hid-cherry:hid-logitech:hid-logitech-dj:hid-logitech-hidpp:hid-lenovo:hid-microsoft:hid_multitouch:jbd2:mbcache:crc32c_intel:crc32c_generic:ext4"
LUKSDEV=""
ROOTDEV="/dev/sda3"
ROOTFS="ext4"
RESUMEDEV=""
RAID=""
LVM=""
UDEV="1"
WAIT="1"

After inspecting its output, you should do:

Code:

/usr/share/mkinitrd/mkinitrd_command_generator.sh -c > /etc/mkinitrd.conf

Further, you can tune the /etc/mkinitrd.conf as you like and please note that you should to this step once. After all, it's just a config file.

2. Generating the initrd

Assuming that you intend to use the generic kernel 6.1.45, you should do:

Code:

mkinitrd -c -k 6.1.45 -o /boot/initrd-6.1.45.img

And yes, the GRUB2 scripts likes the versioned initrds.

3. Installing GRUB2

IF you have a hardware with the legacy BIOS, you should execute this command:

Code:

grub-install --target=i386-pc --recheck /dev/sdX

IF you have a hardware using UEFI, you should mount /boot/efi and execute this command:

Code:

grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=Slackware --recheck

4. Updating the GRUB2 configuration

All you have to do is to execute this command:

Code:

grub-mkconfig -o /boot/grub/grub.cfg

For your convenience in future, you can create this /usr/sbin/update-grub script:

Code:

#!/bin/sh

set -e

exec grub-mkconfig -o /boot/grub/grub.cfg "$@"

And there is time to reboot and enjoy your GRUB2 setup with the generic kernel.

On the future, each time you upgrade the kernel, you should execute these 2 commands:

Code:

mkinitrd -c -k <KERNEL VERSION> -o /boot/initrd-<KERNEL VERSION>.img

grub-mkconfig -o /boot/grub/grub.cfg

That's all.

Jeebizz · 08-12-2023, 01:25 PM

Quote:

Originally Posted by volkerdi

Obviously GRUB2.

In the words of Zoidburg:

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cwizardone · 08-12-2023, 01:26 PM

Quote:

Originally Posted by Jeebizz

Fair enough but I guess I should also have clarified - as Pat alluded to switching to GRUB; so I assumed just GRUB as perhaps GRUB2 is too bleeding edge still for Slackware? I don't know.

GRUB2, https://www.gnu.org/software/grub/
Scroll down to "GRUB Legacy," click on it and you will get a brief history, etc.

volkerdi · 08-12-2023, 01:27 PM

Quote:

Originally Posted by Emerson

May I express my opinion? No? Thought so.
Anyhow, GRUB(2) is the most pointless and useless piece of software for a distro like Slackware (or Gentoo). There are tens of megabytes of junk installed to the hard drive doing what ..? All this may be great for Ubuntu with automated kernel upgrades, but we are not running Ubuntu here.
Nowadays we have EFI boot and every mobo has boot menu. Install as many EFI stub kernels as you want and don't waste your time with a bootloader which is more like an OS. You can even multiboot using this mobo menu, you can have a bootloader(s) there for another OS which cannot boot directly from EFI as Linux does.
Or for gods sake, if you just must have a bootloader then Syslinux is absolutely great for legacy boot, LiLo is to be considered, too.

I like GRUB2 just about as much as you do, but the fact is that at this point it is the only bootloader for Linux that actually works in all circumstances. And if that's the case, then supporting old, rotten bootloaders is a waste of limited resources.

I believe that even booting EFI stub you'll run into the same black screen issues that occur with elilo on some UEFI systems.

marav · 08-12-2023, 01:29 PM

Quote:

Originally Posted by Jeebizz

Fair enough but I guess I should also have clarified - as Pat alluded to switching to GRUB; so I assumed just GRUB as perhaps GRUB2 is too bleeding edge still for Slackware? I don't know.

Code:

GRUB 2 has replaced what was formerly known as GRUB
 (i.e. version 0.9x), which has, in turn, become GRUB Legacy. 
Enhancements to GRUB are still being made, but the current 
released versions are quite usable for normal operation.

GRUB Legacy is no longer being developed.

https://www.gnu.org/software/grub/

rizitis · 08-12-2023, 01:31 PM

Question: by running mkinitrd -c ...

Code:

mkinitrd -c     Clear  the  existing  initrd tree (by default in /boot/initrd‐tree/)
              first.  If this is not done, running mkinitrd  will  add  additional
              modules to the existing initrd.

what will happen if custom generic kernels exist in the system?

volkerdi · 08-12-2023, 01:41 PM

Quote:

Originally Posted by rizitis

Question: by running mkinitrd -c ...

Code:

mkinitrd -c     Clear  the  existing  initrd tree (by default in /boot/initrd‐tree/)
              first.  If this is not done, running mkinitrd  will  add  additional
              modules to the existing initrd.

what will happen if custom generic kernels exist in the system?

This makes a good point. I do not see any reason why GRUB2, once installed, ever needs to be futzed with again. Is this not one of the selling points of GRUB? Unlike LILO, the files referenced in the GRUB config file can be completely changed out without any requirement to reinstall or reconfigure GRUB. But in order for this to work, *the filenames must remain the same*.

Now, I know that LuckyCyborg loves versioned filenames as used elsewhere almost as much as he believes I love LILO, elilo, etc, but I don't think that's how we want to do this. I think that initrd.gz will be fine as an unversioned file as it's always been. The kernel file will be versioned (as always), but with an unversioned symlink pointing to it (and used in the GRUB config). Then when a new kernel (and symlink) is installed, and the initrd updated, everything should just work concerning GRUB. Versioning a Slackware initrd doesn't make a lot of sense anyway - it can support multiple different kernel versions with a single initrd. What's the filename version supposed to be then?

The scripts that come with GRUB2 as well as things like os-prober are probably not relevant for our purposes as we just want a simple starting configuration. Since we don't plan to mess with it later, you'll be able to change it (or not) without a future update plowing over the top of it.

Also, this method allows managing GRUB2 from a foreign operating system without having to reconfigure anything there after a Slackware kernel/initrd update.

mickski56 · 08-12-2023, 01:55 PM

Whats wrong with limine too new ?

volkerdi · 08-12-2023, 01:59 PM

Quote:

Originally Posted by mickski56

Whats wrong with limine too new ?

Having every functional bootloader included is not essential for our purpose here.