To: ~alpine/users@lists.alpinelinux.org
From: David Demelier <markand@malikania.fr>
Subject: Custom kernel 5.6.2 with luks: unable to mount root
Message-ID: <4ce428a9-eed0-ce97-4cef-87cae578ea36@malikania.fr>
Date: Fri, 3 Apr 2020 11:19:19 +0200
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Hey there,

I'm having few issues with the LTS kernel regarding the iwlwifi driver 
so I wanted to try the latest kernel version by hand.

I had an old kernel configuration that I upgraded to 5.6.2 using `make 
olddefconfig` and checked that every required drivers were still enabled.

I have the following kernel command line:

cryptdm=cryptroot cryptroot=/dev/nvme0n1p2 root=/dev/mapper/cryptroot 
rootfstype=ext4 ro

I also added "cryptsetup" in the features in mkinitfs.conf

But then, with the proper initramfs rebuilt with `mkinitfs 5.6.2` the 
kernel boots and immediately panic with the following error:

VFS: Cannot open root device "mapper/cryptroot" or unknown-block(0,0): 
error -6
Please append a correct "root=" boot option:

Then, a list of devices are listed (including /dev/nvme*)

What I don't understand is why the kernel does not understand that it is 
an encrypted volume and that is has to wait until initramfs ask a 
passphrase for it (the kernel never asks the passphrase, isn't it?).

Here's my kernel config FWIW: https://pastebin.com/mXisHP78

To my understanding, the linux-lts package does not come with any patch, 
so a vanilla kernel should work too. I don't know what could be wrong 
here in my case.

Any help is welcome.

-- 
David