When I run Software Updater, it tells me that there is "Not enough free disk space. The upgrade needs a total of 48.2 M free space on disk ‘/boot’. Please free at least an additional 3,424 k of disk space on ‘/boot’. Empty your trash and remove temporary packages of former installations using ‘sudo apt-get clean’. "
Running the suggested “sudo apt-get clean” produces no output and no change in the behavior of Software Updater. Another suggestion was to run “sudo apt autoremove --purge” – this also made no difference, although it did remove a handful of other packages.
Various ubuntu software sites suggest that the problem is that old kernels should be removed, but all the instructions there refer to “linux-image” packages that should be removed via Synaptic. My system has no “linux-image” packages listed by Synaptic.
When I run “uname -r” in a terminal window, I get “4.4.26-v7+” as the output. Running “ls -ls /boot” shows
16 -rwxr-xr-x 1 root root 14010 Oct 24 17:50 bcm2708-rpi-b.dtb
16 -rwxr-xr-x 1 root root 14273 Oct 24 17:50 bcm2708-rpi-b-plus.dtb
16 -rwxr-xr-x 1 root root 13964 Oct 24 17:50 bcm2708-rpi-cm.dtb
16 -rwxr-xr-x 1 root root 15356 Oct 24 17:50 bcm2709-rpi-2-b.dtb
16 -rwxr-xr-x 1 root root 15992 Oct 24 17:50 bcm2710-rpi-3-b.dtb
16 -rwxr-xr-x 1 root root 15350 Oct 24 17:50 bcm2710-rpi-cm3.dtb
24 -rwxr-xr-x 1 root root 17932 Oct 24 17:50 bootcode.bin
8 -rwxr-xr-x 1 root root 110 Apr 21 2016 cmdline.txt
40 -rwxr-xr-x 1 root root 36155 Oct 24 09:51 config.txt
24 -rwxr-xr-x 1 root root 18693 Mar 15 2016 COPYING.linux
8 -rwxr-xr-x 1 root root 2525 Oct 24 17:50 fixup_cd.dat
8 -rwxr-xr-x 1 root root 6621 Oct 24 17:50 fixup.dat
16 -rwxr-xr-x 1 root root 9744 Oct 24 17:50 fixup_db.dat
16 -rwxr-xr-x 1 root root 9744 Oct 24 17:50 fixup_x.dat
4136 -rwxr-xr-x 1 root root 4229336 Oct 24 17:50 kernel7.img
4032 -rwxr-xr-x 1 root root 4127640 Oct 24 17:50 kernel.img
8 -rwxr-xr-x 1 root root 1494 Mar 15 2016 LICENCE.broadcom
16 drwxr-xr-x 2 root root 16384 Oct 16 11:49 overlays
624 -rwxr-xr-x 1 root root 633508 Oct 24 17:50 start_cd.elf
4840 -rwxr-xr-x 1 root root 4949060 Oct 24 17:50 start_db.elf
2752 -rwxr-xr-x 1 root root 2816836 Oct 24 17:50 start.elf
3816 -rwxr-xr-x 1 root root 3899492 Oct 24 17:50 start_x.elf
Can any of these files be safely removed? Is there some Raspberry-specific naming of the kernels that I can use in Synaptic to find one to remove?
Thanks for your help.