Slackware and the grub boot loader.

stf92 · 07-02-2020, 08:27 AM

Quote:

Originally Posted by colorpurple21859

Do you have an initrd.gz?
If you only use the first slackware entry to boot and it works without the initrd.gz line, I wouldn't worrry about it.

Otherwise grub is versatile so there is several ways of doing this.
1. As per Richard Cranium post 11

2. Copy the slackware menu entries that you want to use to /etc/grub.d/40_custom and insert the initrd=/boot/initrd.gz between the vmlinuz line and the } line and run update-grub. Be aware that is file is static and won't change with a kernel version change.

3.Chainload slackware grub.cfg with this entry [...]

I don't have an initrd.gz in the Slackware partition. The initrd is generated by mkinitrd which I can't run because I can't boot Slackware yet. So, let's omit the initrd thing for the moment.

After running grub-mkconfig under debian and with the slackware 14.2 already installed, I booted and got this:

Code:

Kernel panic - not syncing: VFS: unable to mount root fs on unknown-block (0,0)

Here a new piece of information: this laptop uses eMMC instead of a hard disk. Though I have already successfully installed debian and linux arch on it, I think Slackware simply does not understand it, which is odd because the installer works fine, writing to the eMMC a lot of data.

In view of this, I'll start a separate thread under the title "Slackware and eMMC". Thanks for all the feedback.

BrunoLafleur · 07-02-2020, 10:02 AM

Quote:

Originally Posted by stf92

I don't have an initrd.gz in the Slackware partition. The initrd is generated by mkinitrd which I can't run because I can't boot Slackware yet. So, let's omit the initrd thing for the moment.

If you install the Slackware, there is a initrd.gz by default which comes with the default huge kerneL.

I don't think Slackware will boot without it.

enorbet · 07-02-2020, 10:11 AM

Quote:

Originally Posted by BrunoLafleur

If you install the Slackware, there is a initrd.gz by default which comes with the default huge kerneL.

I don't think Slackware will boot without it.

Is that actually accurate? It is my understanding that what makes the Huge kernel huge is almost everything is checked and therefore no initrd is needed. IIRC a sample initrd is included for the Generic kernel only with the expectation that each user will generate his own for his hardware and software specifics. FWIW the only reason I would ever employ initrd is for encrypted file systems. I have never used one in over 20 years.

cwizardone · 07-02-2020, 10:17 AM

Quote:

Originally Posted by BrunoLafleur

If you install the Slackware, there is a initrd.gz by default which comes with the default huge kerneL.

I don't think Slackware will boot without it.

As pointed out in post #18, the huge kernel does not need a initrd.gz to boot.

bassmadrigal · 07-02-2020, 10:25 AM

Quote:

Originally Posted by BrunoLafleur

If you install the Slackware, there is a initrd.gz by default which comes with the default huge kerneL.

I don't think Slackware will boot without it.

This is partially true. On -current and most likely 15.0+ releases, Slackware will include an initrd after installation, but it will be booting the generic kernel with that initrd. The huge kernel is still available (for now) if people want to switch to it. For 14.2 and earlier, it will install both the generic and huge and boot off the huge by default. The admin would be required to set up and initrd and switch to the generic kernel, which is recommended by Pat.

cwizardone · 07-02-2020, 10:37 AM

-current boots the huge kernel perfectly without a initrd.gz.
With "modern" hardware there is no perceived benefit to using the generic kernel and a initrd.gz.

colorpurple21859 · 07-02-2020, 11:30 AM

I think you will need initrd.gz with eMMC
at the grub menu highlight the slackware menu entry Press e for edit
add a new line after the linux line with this

initrd /boot/initrd.gz

boot and see what happens.
If that doesn't work and/or a initrd.gz doesn't exist, at he grub menu edit the linux line
change the root=/dev/mmcblk0p2 on the linux line to root=UUID=2d63e598-b1b4-4e32-a781-9fe9ceae2c11

Petri Kaukasoina · 07-02-2020, 11:34 AM

Quote:

Originally Posted by stf92

I don't have an initrd.gz in the Slackware partition.

Though I have already successfully installed debian and linux arch on it, I think Slackware simply does not understand it, which is odd because the installer works fine, writing to the eMMC a lot of data.

Quote:

Originally Posted by BrunoLafleur

If you install the Slackware, there is a initrd.gz by default which comes with the default huge kerneL.

I don't think Slackware will boot without it.

Quote:

Originally Posted by enorbet

Is that actually accurate? It is my understanding that what makes the Huge kernel huge is almost everything is checked and therefore no initrd is needed. IIRC a sample initrd is included for the Generic kernel only with the expectation that each user will generate his own for his hardware and software specifics. FWIW the only reason I would ever employ initrd is for encrypted file systems. I have never used one in over 20 years.

I don't know anything about eMMC. But the installer actually is an initrd and it contains lots of modules, see

Code:

bsdtar tvf slackware64-14.2/isolinux/initrd.img lib/modules/4.4.14

so if the installer can write to the eMMC but the installed system does not recognize it, it's possible that even the huge kernel may need an initrd for an installed system to boot, with some modules the installer's initrd.img has.

stf92 · 07-02-2020, 11:37 AM

Quote:

Originally Posted by colorpurple21859

I think you will need initrd.gz with eMMC
at the grub menu highlight the slackware menu entry Press e for edit
add a new line after the linux line with this

initrd /boot/initrd.gz

boot and see what happens.
If that doesn't work and/or a initrd.gz doesn't exist, at he grub menu edit the linux line
change the root=/dev/mmcblk0p2 on the linux line to root=UUID=2d63e598-b1b4-4e32-a781-9fe9ceae2c11

I looked at the /boot directory in the slackware partition and did not find any initrd.gz. What is UUID=2d63e598-b1b4-4e32-a781-9fe9ceae2c11?

Petri Kaukasoina · 07-02-2020, 11:52 AM

Quote:

Originally Posted by stf92

I think Slackware simply does not understand it, which is odd because the installer works fine, writing to the eMMC a lot of data.

While running the installer, what does "lsmod" print out (in another virtual console)?

colorpurple21859 · 07-02-2020, 12:09 PM

That is the blkid of the slackware partition, but just remembered that has to have an initrd to work, so scratch that one.

colorpurple21859 · 07-02-2020, 12:16 PM

open a terminal in debian as root, this is assuming "/dev/mmcblk0p2" this is the correct /dev for slackware partition.

Code:

mount /dev/mmcblk0p2 /mnt
mount --bind /dev /mnt/dev
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
mount -o bind /run /mnt/run
chroot /mnt
sh /usr/share/mkinitrd/mkinitrd_command_generator.sh

run the command genererated for mkinitrd

Code:

exit
update-grub

stf92 · 07-02-2020, 12:39 PM

Quote:

Originally Posted by Petri Kaukasoina

While running the installer, what does "lsmod" print out (in another virtual console)?

Well, among the lines printed out there is:

Code:

mmc_core 97537 4 mmc_block,sdhci,sdhci_acpi,sdhci_pci

Petri Kaukasoina · 07-02-2020, 12:49 PM

Quote:

Originally Posted by stf92

Well, among the lines printed out there is:

Code:

mmc_core 97537 4 mmc_block,sdhci,sdhci_acpi,sdhci_pci

So, the huge kernel needs at least those modules in initrd.

stf92 · 07-02-2020, 12:51 PM

Quote:

Originally Posted by colorpurple21859

open a terminal in debian as root, this is assuming "/dev/mmcblk0p2" this is the correct /dev for slackware partition.

Code:

mount /dev/mmcblk0p2 /mnt
mount --bind /dev /mnt/dev
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
mount -o bind /run /mnt/run
chroot /mnt
sh /usr/share/mkinitrd/mkinitrd_command_generator.sh

run the command genererated for mkinitrd

Code:

exit
update-grub

All sh did was to print the following:

Code:

Modules for kernel 4.19.0-8-amd64 aren't installed

Could it be because I installed 14.2 32-bit and this machine is 64-bit?