I have added the file /etc/initramfs-tools/etc/motd so that it would be available in /etc of the initramfs environment. However, it does not turn up. This is my second try where I gave the file all permissions available (I've also used 600):
root@cow:~# ls -l /etc/initramfs-tools/etc/
total 8
drwx------ 2 root root 4096 Sep 19 00:57 dropbear
-rwxrwxrwx 1 root root 117 Sep 29 15:32 motd
After that I sudo update-initramfs -u, boot into the initramfs environment and log in through SSH via Dropbear, and the file is still not there:
~ # ls -l /etc
total 20
-rw------- 1 root 0 4077 Sep 29 13:44 boottime.kmap.gz
drwx------ 2 root 0 0 Sep 29 13:44 dropbear
-rw-r--r-- 1 root 0 1991 Sep 29 13:44 ld.so.cache
-rw-r--r-- 1 root 0 34 Sep 18 17:24 ld.so.conf
drwxr-xr-x 2 root 0 0 Sep 18 17:25 ld.so.conf.d
drwx------ 2 root 0 0 Sep 29 13:44 lvm
drwx------ 2 root 0 0 Sep 29 13:44 mdadm
drwx------ 2 root 0 0 Sep 29 13:44 modprobe.d
-rw------- 1 root 0 15 Sep 29 13:44 nsswitch.conf
-rw------- 1 root 0 30 Sep 29 13:44 passwd
drwx------ 2 root 0 0 Sep 29 13:44 udev
How should I add it? Why didn't the above way work?