Console on 8250/16550 and compatible serial port
modulename: 8250_early.ko
configname: CONFIG_SERIAL_8250_CONSOLE
Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Serial drivers
└─>Console on 8250/16550 and compatible serial port
In linux kernel since version 2.6.20 (release Date: 2007-02-04)
If you say Y here, it will be possible to use a serial port as the
system console (the system console is the device which receives all
kernel messages and warnings and which allows logins in single user
mode). This could be useful if some terminal or printer is connected
to that serial port.
Even if you say Y here, the currently visible virtual console
(/dev/tty0) will still be used as the system console by default, but
you can alter that using a kernel command line option such as
"console=ttyS1". (Try "man bootparam" or see the documentation of
your boot loader (grub or lilo or loadlin) about how to pass options
to the kernel at boot time.)
If you don't have a VGA card installed and you say Y here, the
kernel will automatically use the first serial line, /dev/ttyS0, as
system console.
You can set that using a kernel command line option such as
"console=uart8250,io,0x3f8,9600n8"
"console=uart8250,mmio,0xff5e0000,115200n8".
and it will switch to normal serial console when the corresponding
port is ready.
"earlycon=uart8250,io,0x3f8,9600n8"
"earlycon=uart8250,mmio,0xff5e0000,115200n8".
it will not only setup early console.
If unsure, say N.
system console (the system console is the device which receives all
kernel messages and warnings and which allows logins in single user
mode). This could be useful if some terminal or printer is connected
to that serial port.
Even if you say Y here, the currently visible virtual console
(/dev/tty0) will still be used as the system console by default, but
you can alter that using a kernel command line option such as
"console=ttyS1". (Try "man bootparam" or see the documentation of
your boot loader (grub or lilo or loadlin) about how to pass options
to the kernel at boot time.)
If you don't have a VGA card installed and you say Y here, the
kernel will automatically use the first serial line, /dev/ttyS0, as
system console.
You can set that using a kernel command line option such as
"console=uart8250,io,0x3f8,9600n8"
"console=uart8250,mmio,0xff5e0000,115200n8".
and it will switch to normal serial console when the corresponding
port is ready.
"earlycon=uart8250,io,0x3f8,9600n8"
"earlycon=uart8250,mmio,0xff5e0000,115200n8".
it will not only setup early console.
If unsure, say N.