Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) Linux Braille Console
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) =====================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) To get early boot messages on a braille device (before userspace screen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) readers can start), you first need to compile the support for the usual serial
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) console (see :ref:`Documentation/admin-guide/serial-console.rst <serial_console>`), and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) for braille device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) (in :menuselection:`Device Drivers --> Accessibility support --> Console on braille device`).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) Then you need to specify a ``console=brl``, option on the kernel command line, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) format is::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 	console=brl,serial_options...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) where ``serial_options...`` are the same as described in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) :ref:`Documentation/admin-guide/serial-console.rst <serial_console>`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) So for instance you can use ``console=brl,ttyS0`` if the braille device is connected to the first serial port, and ``console=brl,ttyS0,115200`` to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) override the baud rate to 115200, etc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) By default, the braille device will just show the last kernel message (console
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) mode).  To review previous messages, press the Insert key to switch to the VT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) review mode.  In review mode, the arrow keys permit to browse in the VT content,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) :kbd:`PAGE-UP`/:kbd:`PAGE-DOWN` keys go at the top/bottom of the screen, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) the :kbd:`HOME` key goes back
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) to the cursor, hence providing very basic screen reviewing facility.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) Sound feedback can be obtained by adding the ``braille_console.sound=1`` kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) For simplicity, only one braille console can be enabled, other uses of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) ``console=brl,...`` will be discarded.  Also note that it does not interfere with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) the console selection mechanism described in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) :ref:`Documentation/admin-guide/serial-console.rst <serial_console>`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) For now, only the VisioBraille device is supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) Samuel Thibault <samuel.thibault@ens-lyon.org>