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# Serial device configuration
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menu "Serial drivers"
depends on HAS_IOMEM
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# The new 8250/16550 serial drivers
config SERIAL_8250
tristate "8250/16550 and compatible serial support"
select SERIAL_CORE
---help---
This selects whether you want to include the driver for the standard
serial ports. The standard answer is Y. People who might say N
here are those that are setting up dedicated Ethernet WWW/FTP
servers, or users that have one of the various bus mice instead of a
serial mouse and don't intend to use their machine's standard serial
port for anything. (Note that the Cyclades and Stallion multi
serial port drivers do not need this driver built in for them to
work.)
To compile this driver as a module, choose M here: the
module will be called 8250.
[WARNING: Do not compile this driver as a module if you are using
non-standard serial ports, since the configuration information will
be lost when the driver is unloaded. This limitation may be lifted
in the future.]
BTW1: If you have a mouseman serial mouse which is not recognized by
the X window system, try running gpm first.
BTW2: If you intend to use a software modem (also called Winmodem)
under Linux, forget it. These modems are crippled and require
proprietary drivers which are only available under Windows.
Most people will say Y or M here, so that they can use serial mice,
modems and similar devices connecting to the standard serial ports.
config SERIAL_8250_CONSOLE
bool "Console on 8250/16550 and compatible serial port"
depends on SERIAL_8250=y
select SERIAL_CORE_CONSOLE
---help---
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.