So to configure dropbear we need to do three things:Generate the key sets.Ensure the key sets persist across reboots.Ensure dropbear starts up automatically every time the system boots.
Source: Thin Clients: Tinycore
The author of this website provides nice, succinct information on thin clients and how to set them up. Today I installed Tiny Core on my thin client Futro S550, using the process:
Initially, use Ubuntu to boot from USB disk, run Gparted to edit the partition of the Compact Flash inside the thin client.(update: this is not necessary, the Partitioning during Tiny Core installation works fine to create a new partition table, or we can install the app Gparted in Tiny Core when booting from USB disk)
- Use Tiny Core to boot from another USB disk (I used the variant Core Plus, the bootable USB was created with Unetbootin from my Ubuntu laptop), then installed Tiny Core on the CF card of the thin client, with “Frugal” method. It was very fast and straightforward.
Then I installed Dropbear for SSH server. There was a slight change in the path of Dropbear, as it was long time the instruction on Parkytowers were written (the lines inside .filetool.lst should not have ‘/’ at the beginning):
echo usr/local/etc/dropbear/dropbear_rsa_host_key >>/opt/.filetool.lst
echo usr/local/etc/dropbear/dropbear_dss_host_key >>/opt/.filetool.lst
echo /url/local/etc/init.d/dropbear start >>/opt/bootlocal.sh
Note: for Tiny Core, since it normally load the whole operating system to RAM, for any change that we want to save it to the disk for future use, we need this procedure:
- put the new file into the file /opt/.filetool.lst
- run the command: filetool.sh -b
I specified /opt and /home to be with /dev/sda1, hence these two directories will not be loaded into RAM, instead they remain on the hard disk (here: CF card).
Things that I could not do yet: boot the thin client without a keyboard (normally that must be changed in the BIOS, however I didn’t find anything in the BIOS settings to skip the keyboard scan during boot).
Update: with thin client Futro S550 the booting process require a keyboard, however with thin client LT310 it is not necessary (indeed, it seems that there is no way to enter the BIOS setting for this LT310 during boot; OpenWRT would complain “BIOS corrupted”, however the thin client still functions well).
Update 2: later I figured the way to access BIOS settings of the thin client LT310, by pressing “Del” during boot.