When switching to a CONFIG_VT=n world, at least on x86 systems, /dev/console becomes /dev/ttyS0. This can cause some undesired effects. /dev/console's behavior is now tied to the physical /dev/ttyS0, which when disconnected can cause isatty() to fail when /dev/ttyS0 is disconnected, and users who upgrade to a theoretical vt-less kernel from their distribution who have a device such as a science instrument connected to their /dev/ttyS0 port will suddenly see it receive kernel log messages. When the new CONFIG_NULL_TTY_CONSOLE option is turned on, this will allow the ttynull device to be leveraged as the default console. Distributions that had CONFIG_VT turned on before will be able to leverage this option to where /dev/console is still backed by a psuedo device, avoiding these issues, without needing to enable the entire VT subsystem. n3rdopolis (2): ttynull: Add an option to allow ttynull to be used as a console device tty: Change order of ttynull to be loaded sooner. drivers/tty/Kconfig | 18 +++++++++++++++++- drivers/tty/Makefile | 3 ++- drivers/tty/ttynull.c | 16 +++++++++++++++- 3 files changed, 34 insertions(+), 3 deletions(-) -- 2.45.2
