Arch Linux

JJJollyjim

Member

Registered: 2013-07-28

Posts: 21

"Unable to find root device '' " when using kernel EFI loader

I am in the process of setting up Arch (dual boot with OSX) on a MacBook Pro Mid-2012 (model 9,2), using reEFInd as an EFI boot manager.

All is well when choosing GRUB from rEFInd, but I would like to switch to using the kernel EFI stub loader.

It is detected by rEFInd, but choosing it quickly shows:

[   0.031649] [Firmware Bug]: ioapic 2 has no mapping iommu, interrupt remappin
g will be disabled
:: running early hook [udev]
starting version 218
:: running hook [udev]
:: Triggering uevents...
ERROR: device '' not found. Skipping fsck.
ERROR: Unable to find root device ''.
You are being dropped to a recovery shell
    Type 'exit' to try and continue booting
sh: can't access tty; job control turned off
[rootfs /]#

I was receiving a similar message when booting with GRUB, until I realised that I had not yet run `grub-mkconfig` (I realise it is bad form to not post the actual error message, but I have no idea how to reproduce that problem now that I have fixed it!).

Is there a similar command I need to run to use the EFI stub loader? Or some other way to get my system booting via the stub loader?

Thanks in advance!

Last edited by JJJollyjim (2015-01-11 07:02:18)

olive

Member

From: Belgium

Registered: 2008-06-22

Posts: 1,490

Re: "Unable to find root device '' " when using kernel EFI loader

Most probably you don't have passed the correct root= option to the kernel so that the kernel cannot, as it says, find its root device. Read the wiki page about refind in order to know how to configure it (https://wiki.archlinux.org/index.php/REFInd). Refind as no fully automatic configuration like grub.

TheSaint

Member

From: my computer

Registered: 2007-08-19

Posts: 1,536

Re: "Unable to find root device '' " when using kernel EFI loader

I'd like to point this out.

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do it good first, it will be faster than do it twice the saint

Spider.007

Member

Registered: 2004-06-20

Posts: 1,176

Re: "Unable to find root device '' " when using kernel EFI loader

Hmm, interesting; I've never heard of the Kernel's EFI Stub Loader. From the message it seems you're simply not passing the root= argument; what does `cat /proc/cmdline` output?

TheSaint

Member

From: my computer

Registered: 2007-08-19

Posts: 1,536

Re: "Unable to find root device '' " when using kernel EFI loader

@ Spider.007
To see what's loading the kernel from BIOS is useful to find it out by

$ efibootmgr -v

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do it good first, it will be faster than do it twice the saint