[ydl-gen] YDL 4.1 and serial port control

[Bill Fink]

Hi Joshua,

On Fri, 25 May 2007, Richardson, Joshua A. wrote:

> Here's another question that has me a bit stumped.  We've been running
> 4.0 on our xserves for quite a while now, but during this build the need
> for a 64 OS has arisen, so that's why I was trying to put 5.0.1 on my
> xserve.  Since I wasn't getting anywhere with that, I went with 4.1.  I
> was able to install it, but only by using a cheap-o video card and
> keyboard, not over a serial port.  Now, even though I have the xserve
> set to boot to run level 3, it always seems to take control away from
> the serial port and tries to pass it to a video card during the boot up
> process.  I can ssh in fine and machine is working as expected, but I
> need to have serial console access.  Any ideas or suggestions on what
> I'm doing wrong?  

I set up a serial console on an XServe a long time ago (running
a 2.4.20 kernel), so some of the details may have changed.

If all you need is serial access once the Linux kernel has started
booting, all you should need is to add something like the following
to the appropriate boot entry in /etc/yaboot.conf and run "ybin -v":

	append="console=ttyS0,38400"

Of course change 38400 to match the baud rate of your serial port.
And you'll need an entry similar to the following in /etc/inittab:

	co:2345:respawn:/sbin/agetty ttyS0 38400 vt100

Finally, add "ttyS0" to /etc/securetty to allow root logins if desired.

The following may have to be adjusted for different XServe
configurations and/or more recent kernels, but it works for
me to also allow interaction with yaboot via the serial port.
Care should be taken when attempting this since you no longer
will get output to the normal video console/monitor.

I set the OpenFirmware parameters input-device and output-device
to scca:38400 (I also had to modify the ofboot.b yaboot script to
change the output from screen to scca).

						-Bill