The E2710 is connected via Wifi to a special USB-A dongle to be inserted into the L5 (or any laptop) USB port. To the OS it behaves then like an USB keyboard and mouse.
The urxvt terminal app in the L5 must be switched to “German” with the L5 OSK then the E2710 behaves like a normal QWERTZ keyboard, and also the German keys for äöü… do fine.
The keys for ^ and ° are working too, even if they have to be pressed twice.
To be able to used Spanish tilded chars in the urxvt terminal app, I crafted a file ~purism/.Xdefaults-pureos which uses the key Alt_L as Mod1:
$ cat ~purism/.Xdefaults-pureos
!
! settings for urxvt for the external keyboard E2710
!
URxvt.keysym.A-a: á
URxvt.keysym.A-A: Á
URxvt.keysym.A-e: é
URxvt.keysym.A-E: É
...
The USB dongle and Wifi keyboard works also on FreeBSD, including the Touchpad; see /var/log/messages below.
Sep 3 16:45:33 c720-1400094 kernel: ugen0.5: <RAPOO Rapoo 2.4G Wireless Touchpad Keyboard> at usbus0
Sep 3 16:45:33 c720-1400094 kernel: ums1 on uhub0
Sep 3 16:45:33 c720-1400094 kernel: ums1: <RAPOO Rapoo 2.4G Wireless Touchpad Keyboard, class 0/0, rev 2.00/1.10, addr 4> on usbus0
Sep 3 16:45:33 c720-1400094 kernel: ums1: 5 buttons and [XYZT] coordinates ID=0
Sep 3 16:45:33 c720-1400094 kernel: ukbd0 on uhub0
Sep 3 16:45:33 c720-1400094 kernel: ukbd0: <RAPOO Rapoo 2.4G Wireless Touchpad Keyboard, class 0/0, rev 2.00/1.10, addr 4> on usbus0
Sep 3 16:45:33 c720-1400094 kernel: kbd2 at ukbd0
Sep 3 16:45:33 c720-1400094 kernel: ukbd1 on uhub0
Sep 3 16:45:33 c720-1400094 kernel: ukbd1: <RAPOO Rapoo 2.4G Wireless Touchpad Keyboard, class 0/0, rev 2.00/1.10, addr 4> on usbus0
Sep 3 16:45:33 c720-1400094 kernel: kbd3 at ukbd1