| 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 serial-console.txt), and for braille device (in Device Drivers -
|Then you need to specify a console=brl, option on the kernel command line, the
|where serial_options... are the same as described in serial-console.txt
|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 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/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 braille_console.sound=1 kernel
|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 serial-console.txt
|For now, only the VisioBraille device is supported.
|Samuel Thibault <email@example.com>