10.1. Linux kernel version 2.5

Kernel version 2.5 is under active development, so this section may be out of date. Version 2.5 includes support for the console to a serial port attached to a USB dongle. The -dj patch to the version 2.5 kernel has a rewritten console layer; it is not known if the rewritten layer effects the user-space use of the serial console.

When configuring the kernel set the following configuration parameters:

Figure 10-1. Kernel configuration for serial console using make menuconfig

Character devices  --->
 [*] Virtual terminal
  [*]   Support for console on virtual terminal
 <*> Standard/generic (8250/16550 and compatible UARTs) serial support
  [*]   Support for console on serial port

This should set the following configuration parameters in /usr/src/linux/.config.

Figure 10-2. Kernel configuration for serial console using .config

CONFIG_VT=y
CONFIG_VT_CONSOLE=y
CONFIG_SERIAL=y
CONFIG_SERIAL_CONSOLE=y

If you also want to use a serial port attached to a USB bus, then in addition to the usual USB configuration, configure the kernel to load the USB console driver and one of the USB serial dongles (our example uses the generic serial dongle).

Figure 10-3. Kernel configuration for USB dongle serial console using make menuconfig

USB Serial Converter support --->
 <M> USB Serial Converter support
 [M] USB Serial Console device support
 [M] USB Generic Serial Driver

This should set the following configuration parameters in /usr/src/linux/.config

Figure 10-4. Kernel configuration for USB dongle serial console using .config

CONFIG_USB_SERIAL=m
CONFIG_USB_SERIAL_CONSOLE=m
CONFIG_USB_SERIAL_GENERIC=m

You should also configure the kernel without the magic SysRq key, as described in Section 9.9.

HOWTOs

10.1. Linux kernel version 2.5