Linux Braille Console¶
To get early boot messages on a braille device (before userspace screen readers can start), you first need to compile the support for the usual serial console (see Documentation/admin-guide/serial-console.rst), and for braille device (in ).
Then you need to specify a
console=brl, option on the kernel command line, the
serial_options... are the same as described in
So for instance you can use
console=brl,ttyS0 if the braille device is connected to the first serial port, and
override the baud rate to 115200, etc.
By default, the braille device will just show the last kernel message (console mode). To review previous messages, press the Insert key to switch to the VT review mode. In review mode, the arrow keys permit to browse in the VT content, PAGE-UP/PAGE-DOWN keys go at the top/bottom of the screen, and the HOME key goes back to the cursor, hence providing very basic screen reviewing facility.
Sound feedback can be obtained by adding the
For simplicity, only one braille console can be enabled, other uses of
console=brl,... will be discarded. Also note that it does not interfere with
the console selection mechanism described in
For now, only the VisioBraille device is supported.
Samuel Thibault <firstname.lastname@example.org>