pi@raspberrypi:~ $ sudo BRANCH=next rpi-update
 *** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
 *** Performing self-update
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 12006  100 12006    0     0   4632      0  0:00:02  0:00:02 --:--:--  4633
 *** Relaunching after update
 *** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
 *** We're running for the first time
 *** Backing up files (this will take a few minutes)
 *** Backing up firmware
 *** Backing up modules 4.4.13+
 *** Downloading specific firmware revision (this will take a few minutes)
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   168    0   168    0     0     61      0 --:--:--  0:00:02 --:--:--    61
100 51.1M    0 51.1M    0     0   468k      0 --:--:--  0:01:51 --:--:--  569k
 *** Updating firmware
 *** Updating kernel modules
 *** depmod 4.4.15+
 *** depmod 4.4.15-v7+
 *** Updating VideoCore libraries
 *** Using HardFP libraries
 *** Updating SDK
 *** Running ldconfig
 *** Storing current firmware revision
 *** Deleting downloaded files
 *** Syncing changes to disk
 *** If no errors appeared, your firmware was successfully updated to 193f081a0ed502b62483aa707a79cf245db9b028
 *** A reboot is needed to activate the new firmware
pi@raspberrypi:~ $ sudo reboot
Connection to 192.168.1.105 closed by remote host.
Connection to 192.168.1.105 closed.
saint@saint-laptop:~$ ssh pi@192.168.1.105
pi@192.168.1.105's password:

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Sun Jul 31 23:58:37 2016 from 192.168.1.103
pi@raspberrypi:~ $ uname -a
Linux raspberrypi 4.4.15+ #898 Thu Jul 21 14:34:19 BST 2016 armv6l GNU/Linux