Every time I update my Pi4, it runs needrestart which complains that I'm using an old kernel version and I should reboot, but rebooting doesn't change anything.
First, I have to precise that:
- I installed a full version on the SD Card (latest one in march 2020)
- I changed my cmdline.txt on the SDCard so as to boot on a hard disk
- The /boot partition is kept on the sd card...
- The image on the hard disk was previously used on RPi3B+. I updated it (dist-upgrade, full-upgrade) and it works quite well on the RPi4 except that needrestart says:
Pending kernel upgrade!
Running kernel version: 4.19.97-v7l+
Diagnostics: The currently running kernel version is not the expected kernel version 4.19.97-v8+.
Restarting the system to load the new kernel will not be handled automatically, so you should consider rebooting.
The /boot (on the SD card) and /lib/modules (on the hard disk) directories contain:
pi@raspberrypi ~ $ ls /lib/modules/
4.14.78+ 4.14.78-v7+ 4.19.97+ 4.19.97-v7+ 4.19.97-v7l+ 4.19.97-v8+
pi@raspberrypi ~ $ ls /boot
bcm2708-rpi-b.dtb bcm2710-rpi-3-b-plus.dtb fixup4.dat kernel7.img start4.elf
bcm2708-rpi-b-plus.dtb bcm2710-rpi-cm3.dtb fixup4db.dat kernel7l.img start4x.elf
bcm2708-rpi-cm.dtb bcm2711-rpi-4-b.dtb fixup4x.dat kernel8.img start_cd.elf
bcm2708-rpi-zero.dtb bootcode.bin fixup_cd.dat kernel.img start_db.elf
bcm2708-rpi-zero-w.dtb cmdline.txt fixup.dat LICENCE.broadcom start.elf
bcm2709-rpi-2-b.dtb config.txt fixup_db.dat overlays start_x.elf
bcm2710-rpi-2-b.dtb COPYING.linux fixup_x.dat start4cd.elf 'System Volume Information'
bcm2710-rpi-3-b.dtb fixup4cd.dat issue.txt start4db.elf
I ran for each img in /boot the command:
$ strings /boot/kernelXXX.img | grep -m 1 '^Linux version'
No output except for kernel8.img for which I got:
Linux version 4.19.97-v8+ (dom@buildbot) (gcc version 5.4.0 20160609 (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9)) #1294 SMP PREEMPT Thu Jan 30 13:27:08 GMT 2020
So I made a backup of kernel.img and copied kernel8.img to kernel.img, then reboot, but nothing changed...
Then I made a backup of kernel7l.img and (as the current version is 4.19.97-v7l+) copied kernel8.img to kernel7l.img, and reboot, but then no boot at all...
Back to the kernel7l.img and the initial problem remains...
I saw in another post that I can force it by using kernel=xxx in config.txt but that it is not the normal way it should work so I'd like to avoid doing this if it prevents me from changing to newer versions in the future. I'm also a little shy for using rpi-update with all the warnings around...
What should I do to move to the latest version of the kernel which is already installed on my Pi ???