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How to redirect kernel messages to serial console

Started by tamamontu February 10, 2010
Hi, I am trying to redirect kernel message to serial console. 

I am trying to modify LCD device driver for cirrus EP9307 board. We are
using 2.6.8.1 kernel and reboot as bootloader. 

I have enabled support for serial console in kernel config using
menuconfig. The default console is set to tty0 which is lcd in our case.
How can i change this to ttys0(uart1).

On net there is some information about changing this using kernel
parameters. 

In our system reboot unzips the kernel image and loads it. 

----------------------------------------------------------------------------------------------------------------------------------
+
Ethernet eth0: MAC address 00:00:00:00:68:34
IP: 192.168.254.10
0/255.255.255.0, Gateway: 192.168.254.254
Default server: 192.168.254.254, DNS server IP: 192.168.254.254

RedBoot(tm) bootstrap and debug environment [ROMRAM]
Non-certified release, version v2_0 - built 10:15:31, Feb 5 2010

Platform: Cirrus Logic EDB9307 Board (ARM920T) Rev A
Copyright (C) 2000, 2001, 2002, Red Hat, Inc.

RAM: 0x00000000-0x04000000, 0x00041f68-0x03fbd000 available
FLASH: 0x60000000 - 0x62000000, 128 blocks of 0x00040000 bytes each.
== Executing boot script in 1.000 seconds - enter ^C to abort

RedBoot> fis load ramdisk.gz

RedBoot> fis load zImage

RedBoot> exec -r 0x800000 -s 0xC00000
Using base address 0x0008
0000 and length 0x0012f580

Uncompressing Linux.........................................
........................................... done, booting the kern
el.



Please press Enter to activate this console.

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cheers	   
					
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tamamontu <pkm_munot1@n_o_s_p_a_m.hotmail.com>
  wibbled on Wednesday 10 February 2010 05:15

> Hi, I am trying to redirect kernel message to serial console. > > I am trying to modify LCD device driver for cirrus EP9307 board. We are > using 2.6.8.1 kernel and reboot as bootloader. > > I have enabled support for serial console in kernel config using > menuconfig. The default console is set to tty0 which is lcd in our case. > How can i change this to ttys0(uart1). > > On net there is some information about changing this using kernel > parameters.
You'll need to append this to the boot loader line: console=ttyS0,9600 or variations on that (9600 is the baud rate and ttyS0 is the device name - this could be something else on your setup) More info here: http://www.vanemery.com/Linux/Serial/serial-console.html -- Tim Watts Managers, politicians and environmentalists: Nature's carbon buffer.
tamamontu <pkm_munot1@n_o_s_p_a_m.hotmail.com>
  wibbled on Wednesday 10 February 2010 05:15

> Hi, I am trying to redirect kernel message to serial console. > > I am trying to modify LCD device driver for cirrus EP9307 board. We are > using 2.6.8.1 kernel and reboot as bootloader. > > I have enabled support for serial console in kernel config using > menuconfig. The default console is set to tty0 which is lcd in our case. > How can i change this to ttys0(uart1). > > On net there is some information about changing this using kernel > parameters. > > In our system reboot unzips the kernel image and loads it.
I'll also add - make sure console over serial is enabled in your kernel build.