Loading a custom driver automatically at boot time

Turbocapitalist · 08-29-2022, 06:48 AM

I have a hardware driver which I must build by hand from the vendor's Git repository. That part works fine, though I would prefer an official, generic APT package. The module loads manually no problem, but what do I change and where in order to have the module loaded at boot time?

Code:

$ sudo insmod /usr/lib/modules/5.18.0-4-amd64/kernel/drivers/vendor/vendor.ko

$ uname -a
Linux laptop 5.18.0-4-amd64 #1 SMP PREEMPT_DYNAMIC Debian 5.18.16-1 (2022-08-10) x86_64 GNU/Linux

$ lsb_release -rd
Description:	Devuan GNU/Linux 5 (daedalus/ceres)
Release:	5

And does it matter that the following don't match up?

Code:

$ uname -r -v
5.18.0-4-amd64 #1 SMP PREEMPT_DYNAMIC Debian 5.18.16-1 (2022-08-10)

PS. Some of the above is blocked by clownflare, specifically the utility which starts with "u".

Arnulf · 08-29-2022, 01:00 PM

If you won't call a spade a spade it will be nearly impossible to help you.

business_kid · 08-29-2022, 01:30 PM

why not build it into the initrd or specify it's loading in grub? It saves you farting about with insmod.

Turbocapitalist · 08-29-2022, 01:33 PM

Quote:

Originally Posted by business_kid

... or specify it's loading in grub?

Because I find GRUB2 terribly confusing, difficult, risky, and overly complex. I can see the GRUB2 route working if I can figure it out after a lot of experimental reboots. But I'd like to postpone that approach if possible.

I was hoping that there would simply be a file somewhere in /etc/ where I could list the module, perhaps with full path if necessary, and it would be loaded upon boot.

business_kid · 08-30-2022, 04:21 AM

Then the initrd is the way to go. Just rebuild the initrd, or add your module to /boot-initrd-tree and rebuild it without clearing the tree. Being honest, with uefi I use elilo.

What I found was that on the EFI partition, in the EFI directory, there's a directory for each boot option like this

Code:

tree /boot/efi
/boot/efi
└── EFI
    ├── Boot
    │** └── bootx64.efi
    ├── Microsoft
[SNIP VAST REAMS OF PURE M$ WASTE OF SPACE]    
    └── Slackware
        ├── elilo.conf
        ├── elilo.efi
        ├── initrd-5.15.27.gz
        └── vmlinuz-generic-5.15.27

The efi is the executable, the kernel & initrd are there, & elilo.conf. There'll be something similar for all the other boot options

EDIT: You don't appear to have boot options in elilo.

petelq · 08-30-2022, 04:47 AM

Put the module in /etc/modules-load.d.

Turbocapitalist · 08-30-2022, 07:26 AM

Quote:

Originally Posted by petelq

Put the module in /etc/modules-load.d.

Thanks. I tried putting the name in a .conf file there, both just the module.ko and the full path. Neither caused the module to load on boot. So I am missing something in the process.

I'll look at GRUB2 next when I can plan some reboots.

hazel · 08-30-2022, 08:10 AM

There used to be a modprobe file or a modprobe.d directory to put that kind of thing in. But I'm pretty sure it didn't use the .ko suffix in module names.

business_kid · 08-30-2022, 10:23 AM

Yeah, etc/modprobe.d/ is it, but / isn't even mounted ro yet.

The initrd is the place - if he has one.