Using a Serial Console

Although you might have set up a serial console in the EFI boot manager, Linux defaults to a VGA console. If no VGA device is present, console output is directed to a stub device (for example, not visible.) To specify a serial console, you must pass the console= parameter to the kernel. This can either be done as an extra parameter to the kernel or by means of the parameter append=line in elilo.conf. For example:

Manual Boot Option   ------------------  fs0:\> elilo linux "console=ttyS0" 
     ELILO boot: linux console=ttyS0 

     Automatic via elilo.conf
     ------------------------
     append="console=ttyS0" 

	IMPORTANT: Exactly one UART must be selected in the EFI Console-In/Out tables for a serial console to work. The UART selected in this table is ttyS0.

The format of the console parameter is as follows:

console=ttySn[,spb] 

n = Serial line 

where:

For a 115200 baud console, the following syntax is used:

console=ttyS0,115200n8

	NOTE: If you are using a Linux distribution that uses kernel revision 2.6.10 or later (Post RHEL4 or SLES9), this method of specifying a console will not work. For more information on serial ports with these kernels, see the Linux Cross Reference website: http://lxr.linux.no/source/Documentation/ia64/serial.txt