How to use mhwd-kernel in chroot?

Chrysostomus · 24 January 2017 15:54

I would like to install kernels with

 mhwd-kernel i <kernels>

in a chroot to a system with just base installed. I have been been using arch-chroot like this in my script:

 arch-chroot $MOUNTPOINT /bin/bash -c "mhwd-kernel -i"

However, mhwd-kernel returns this pacman error:

 error: no targets specified (use -h for help)

Mhwd itself recognizes the inputted kernels, because if it does not, it gives this error:

Error: Invalid argument.
Please choose one of the available kernels:
   * linux310
   * linux312
   * linux316
   * linux318
   * linux41
   * linux410
   * linux44
   * linux48
   * linux49
   * linux-rt-lts-manjaro
   * linux-rt-manjaro

So for some reason, mhwd-kernel does not pass any packages to pacman when ran in chroot.

Any ideas how to get around this?

kainonergon · 24 January 2017 17:46

Hi. I think the reason is that mhwd-kernel uses uname -r to detect what kernel is currently running. With chroot it gives kernel running on main system, that might not be installed on chrooted system. So pacman -Qqs "$current" gives empty list instead of valid list of installed packages.

Chrysostomus · 24 January 2017 18:11

Thanks! So I probably can't fix it with forking mhwd... Or maybe I could echo the right kernel name somewhere in /mnt before chrooting? Need to check where uname reads its values...

Hmm... https://bbs.archlinux.org/viewtopic.php?id=82334

Chrysostomus · 24 January 2017 18:52

Maybe I could install fakeuname (temporarily?) in /mnt, use it to run mhwd-kernel kernel and possibly remove it afterwards... I'll look into this.

artoo · 24 January 2017 18:54

Try manjaro-chroot, its part of manjaro-tools.

Chrysostomus · 24 January 2017 18:59

I tried, it seems that

 manjaro-chroot $MOUNTPOINT "mhwd-kernel -i"

Does the same as the arch-chroot thing I had. I switched the script to use it few hours ago, so I can drop arch-install-scripts dependency. It still has the same issue with mhwd-kernel though.

Chrysostomus · 24 January 2017 19:26

Okay, that fakeuname thingy works as intented, but it seems that it does not help with mhwd-kernel.

eugen-b · 24 January 2017 19:53

Is mhwd-chroot worth a try at least for a test case? It actually does the steps of manual chrooting.

Chrysostomus · 24 January 2017 21:30

Tried now. Does not work. The chroot is fine, its just that mhwd-kernel does not work in chroot

kainonergon · 25 January 2017 00:24

Maybe you can try to modify mhwd-kernel? Add a parameter that will override or force what kernel is currently running. Then you can set that parameter to kernel installed in chrooted system and it should work.

Chrysostomus · 25 January 2017 05:05

Good idea, but it will not work because uname already reports the running kernel in chroot. The issue must be something else.

Also, I just took a look at mhwd-kernel code. I can't find the part that would detect needed kernel modules based on hardware. It seems mhwd does this outside mhwd-kernel somehow, so using mhwd-kernel does not achieve what I want anyway.

kainonergon · 25 January 2017 08:30

Well, it seems that mhwd-kernel just determines what modules are installed for current kernel and then installs the same modules for new kernel.

Chrysostomus · 25 January 2017 08:33

Yeah. So it is probably something in the manjaro-live-utils that actually determines the modules.

Chrysostomus · 26 January 2017 05:27

Okay, I looked through live-cd stuff. I didn't see any point where it would detect and install say.. broadcom-wl. It just runs mhwd {non}free, based on how system was started. I'll take a look at if that command actually looks for wireless drivers.

eugen-b · 26 January 2017 08:35

I remember I use to get the boot message "Running mhwd-live cript..."

Chrysostomus · 26 January 2017 08:38

Yeah, I read the script. It just checks if you booted live media with free, nonfree or vesa drivers and runs mhwd command to install those drivers.

Chrysostomus · 26 January 2017 13:08

Found it, it seems that kernel modules are chosen by the same mhwd that installs graphics drivers:

github.com

manjaro/mhwd/blob/master/scripts/mhwd

#!/bin/bash

MHWDDEVICES=()

### Module Functions ###

MHWD_HEADING()
{
    echo '##' > "$1"
    echo '## Generated by mhwd - Manjaro Hardware Detection' >> "$1"
    echo '##' >> "$1"
    echo ' ' >> "$1"
    echo ' ' >> "$1"
}

MHWD_IS_DEVICE()
{
    local CCLASSID="$1"
    local CVENDORID="$2"
    local CDEVICEID="$3"

This file has been truncated. show original

So theoretically manjaro-architect should already install the right drivers unless user skips the graphics driver installation part.

system · 25 February 2017 13:09

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