# access via minicom

## luca

Hi All,

I have a GenToo PC without a monitor, once in a while it stops somewhere in its boot process. Now I would like to make access via minicom (serial), to see what is happening.

But minicom requires some options, like 'Bps/Par/Bits (bit rate)..... Any suggestions what this one should be ?

Thanks in advance

Luca

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## NeddySeagoon

luca,

Your headless box will need a kernel comppiled to support a serial console.

The serial port settings can be passed as kernel parameters. Its all documented here 

```
/usr/src/linux/Documentation/serial-console.txt
```

Set minicom to whatever you define on the headless box.

9600,n,1 was a popular serial terminal defualt.

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## jeanluca

I cannot find the option to turn on Serial support ? Any suggestions where that is ?

Thnx

Luca

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## luispa

 *luca wrote:*   

> 
> 
> I have a GenToo PC without a monitor, once in a while it stops somewhere in its boot process. Now I would like to make access via minicom (serial), to see what is happening.
> 
> But minicom requires some options, like 'Bps/Par/Bits (bit rate)..... Any suggestions what this one should be

 

What do you want:

- Access from this "Gentoo PC" to other equipment using its serial port (i.e. COMx) using minicom

or

- Enable the serial port of this "Gentoo PC" as the output device for the console messages, because you don't have a Monitor, so other equipment can connect to it.

luis

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## karl_rister

The kernel options that you are looking for are located down this path:

Device Drivers->Character Devices->Serial Drivers

The options that you want to enable are these:

8250/16550 and compatible serial support

Console on 8250/16550 and compatible serial port

Once you have the kernel built with those options and it is installed and booting you have a few more things to do.  Assuming that you have Grub, the following will allow you to control it from the serial port and then see kernel output as the system boot.

Add these lines to your grub.conf file:

serial --unit=0 --speed=115200

terminal --timeout=10 serial console

This tells grub to work on the serial port at a 115200 baud (as suggested earlier 9600 is a common one but that is very slow, 115200 is much more bearable).  It also tells grub to print a message for 10 seconds before actually hitting the menu, this gives you the chance to override the serial setting and use grub from the normal console as it cannot work on both at the same time.

You then need to add the following to each kernel line that you want to be able to use in order to see kernel boot output:

console=tty0 console=ttyS0,115200

So a line would look something like:

kernel /vmlinuz root=/dev/something console=tty0 console=ttyS0,115200

The last thing that you may want to enable is login on the serial port.  This requires a getty running on the serial port which is setup in /etc/inittab.  On my Gentoo system I see the following in that file:

# SERIAL CONSOLES

#s0:12345:respawn:/sbin/agetty 9600 ttyS0 vt100

#s1:12345:respawn:/sbin/agetty 9600 ttyS1 vt100

You should uncomment the line starting with s0 and change the 9600 to 115200.  If you want to be able to login in as root on the serial console make sure that ttyS0 is in /etc/securetty.

If you have need to use a different serial port (this all assumes com0) then use ttyS* where * is the com number.

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## jeanluca

Sorry for my very late reply, too bussy with other stuff....

But now I've applied your suggestions, and it works, very nice!!

But there are actually 2 questions left. 

When I boot, it waits for me to hit a key:

    Press any key to continue

    Press any key to continue

...........

(10 times, than it continuous booting) its not a big problem, but why does it do that ?

And second, I don't see the boot messages, is there any change I can get those too ? so when there are problems during boot it would be nice to see those, right ?!

Thanks a lot

Luca

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