Since version 6.12 has become the new lts-current kernel I cannot boot my machine any longer.
If at boot-time I choose the older LTS kernel, version 6.6, all goes well… luckily.
The error that I get is:
/dev/root: Can't open blockdev
and then:
Kernel panic - not syncing; VFS; Unable to mount root fs on unknown-block(0,0)
I’ve also installed version 6.13 native, and I get the same error and the same kernel panic.
Something has changes in 6.12, but what?
Thanks for your help!
It sounds like there may be a missing driver for your root device. Can you tell us what it is? A log from a successful boot on the prior working kernel would be helpful.
I followed this guide to capture Kernel Boot Messages:
https://www.clearlinux.org/clear-linux-documentation/guides/kernel/kernel-boot-msg.html
but I now have 3325 lines to read: which text should I try to grep?
You’re looking for lines around and mentioning your boot block device, so something like ‘sd[abcd]’ for SATA drives, ‘nvme’ for M.2 or other native SSDs… But to start with, what are you booting from?
I am having a boot problem in VMware Workstation with latest kernel. Is there a way
to turn on these logs via setup of boot device, I can’t boot but need to see the boot messages.
I think I will be able to this with the boot drive by making to mods to the files in the guide, then
boot. Let me know if this is not the case.
Well, I’m booting a laptop from its 64 GB internal eMMC storage.
/dev/mmcblk0p1 is formatted in FAT
/dev/mmcblk0p2 is formatted in Ext4
francesco@stream~ $ sudo journalctl -b | grep mmcblk
févr. 13 23:18:51 stream kernel: mmcblk0: mmc0:0001 CJTD4R 58.2 GiB
févr. 13 23:18:51 stream kernel: mmcblk0: p1 p2
févr. 13 23:18:51 stream kernel: mmcblk0boot0: mmc0:0001 CJTD4R 4.00 MiB
févr. 13 23:18:51 stream kernel: mmcblk0boot1: mmc0:0001 CJTD4R 4.00 MiB
févr. 13 23:18:51 stream kernel: mmcblk0rpmb: mmc0:0001 CJTD4R 4.00 MiB, chardev (239:0)
févr. 13 23:18:51 stream kernel: mmcblk1: mmc1:59b4 GE4S5 239 GiB
févr. 13 23:18:51 stream kernel: mmcblk1: p1
févr. 13 23:18:51 stream kernel: EXT4-fs (mmcblk0p2): mounted filesystem 0924a0f1-3145-42d9-8ff4-9346562075f7 r/w with ordered data mode. Quota mode: disabled.
févr. 13 23:18:51 stream kernel: XFS (mmcblk1p1): Mounting V5 Filesystem 4db552d0-519a-49d2-9e45-44fa34cb4c91
févr. 13 23:18:51 stream kernel: XFS (mmcblk1p1): Ending clean mount
(As you see, the PC has also an xfs formatted drive; I’ve created a fstab file to mount it at boot).
Thanks. And in the failure case, if you can even take a photo of the screen showing other messages around the two you highlighted, that would help. If there’s nothing else, you can also remove “quiet” from and add “loglevel=8” to the kernel command line to increase the chances of seeing an error message specific to the failure.
Thanks a lot.
Here is a photo of the boot process interrupted by the kernel panic, with version 6.12:
I have upgraded to swud 43010 and kernel:
Linux xxxxxx 6.13.2-1541.native #1 SMP PREEMPT Sat Feb 8 01:35:51 PST 2025 x86_64 GNU/Linux
The server is working as expected. Hardware and other versions reported:
lshw -class cpu -short -sanitize; lshw -class display -sanitize ; lshw -class memory -short -sanitize ;
H/W path Device Class Description
=====================================================================
/0/37 processor AMD Ryzen 9 5950X 16-Core Processor
/0/1 processor CPU
/0/2 processor CPU
/0/3 processor CPU
/0/4 processor CPU
/0/5 processor CPU
/0/6 processor CPU
/0/7 processor CPU
/0/8 processor CPU
/0/9 processor CPU
/0/a processor CPU
/0/b processor CPU
/0/c processor CPU
/0/d processor CPU
/0/e processor CPU
/0/f processor CPU
/0/10 processor CPU
/0/11 processor CPU
/0/12 processor CPU
*-display
description: VGA compatible controller
product: DG2 [Arc A770]
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:0c:00.0
version: 08
width: 64 bits
clock: 33MHz
capabilities: pciexpress msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:43 memory:fb000000-fbffffff memory:d0000000-dfffffff memory:c0000-dffff
H/W path Device Class Description
=====================================================================
/0/0 memory 64KiB BIOS
/0/31 memory 32GiB System Memory
/0/31/0 memory 16GiB DIMM DDR4 Synchronous Unbuffered (Unregistered) 2400 MHz (0.4 ns)
/0/31/1 memory [empty]
/0/31/2 memory 16GiB DIMM DDR4 Synchronous Unbuffered (Unregistered) 2400 MHz (0.4 ns)
/0/31/3 memory [empty]
/0/34 memory 1MiB L1 cache
/0/35 memory 8MiB L2 cache
/0/36 memory 64MiB L3 cache
#
swupd info ; echo "gnome version"; gnome-shell --version
Distribution: Clear Linux OS
Installed version: 43010
Version URL: https://cdn.download.clearlinux.org/update
Content URL: https://cdn.download.clearlinux.org/update
gnome version
GNOME Shell 47.4
I’ve just found this:
which leads me to think about newly unsupported CPUs: could that be the case? Is there an announce somewhere? Thanks.
I doubt we’ve consciously removed any CPU support. Maybe @william.douglas can clarify.
We have not removed CPUs supported in 6.12.
Thanks. So the mystery remains…
Looks like I found the issue. MMC support was unintentionally made a module in 6.12. Fix for that is coming and I added some testing to avoid that from getting out in the future. Thanks!
This is what bit us:
https://lists.trustedfirmware.org/archives/list/op-tee@lists.trustedfirmware.org/thread/M35XZ7YGR7WRPZ2MZP273G4E5H3XILUE/
This code change automatically downgraded CONFIG_MMC_BLOCK from built-in to a module because CONFIG_RPMB was added as a module by default.
Wow, good catch!
Thanks a lot @william.douglas and @btwarden : maybe it would be useful to close to GitHub issue as well, to warn people not using the forum, what do you think?
Anyway, to feel safer I’ve now installed linux-ltsprev aside to linux-ltscurrent…