Serial console trouble: loader and login works, but no kernel messages

Danny Braniss danny at cs.huji.ac.il
Wed Aug 26 16:04:38 UTC 2009


> On Aug 23, 2009, at 14:18, Thomas Backman wrote:
> 
> > First off: Not subscribed to this list, please make sure to Cc me if  
> > you don't reply directly. :)
> >
> > Anyway, I finally got my null modem cable, and plugged in in between  
> > a machine running 8.0-BETA2 and one running WinXP using Hyperterminal.
> >
> > My settings:
> >
> > /boot/loader.conf:
> > boot_multicons="YES"
> > boot_serial="YES"
> > comconsole_speed="115200"
> > console="comconsole,vidconsole"
> >
> > /etc/ttys:
> > # Serial terminals
> > # The 'dialup' keyword identifies dialin lines to login, fingerd etc.
> > ttyu0   "/usr/libexec/getty std.115200" vt100   on secure
> >
> > /boot.config (which is read properly):
> > -Dh -S115200
> >
> > Anything wrong in the above?
> > Hyperterminal is set to 115200 bps, 8 bits, no parity, 1 stop bit,  
> > and no flow control (if that's the correct translation to English).
> >
> > On the serial console, I go from the screen with the FreeBSD logo,  
> > with single-user options etc. (which works fine), and then nothing,  
> > until a login tty pops up (which also works fine). The main, if not  
> > only, reason I want a serial console is to be able to use it for  
> > single user mode, DDB, and so on.
> > All kernel messages, and all rc messages are seen only on the  
> > graphics card; the serial console receives nothing but the "/ 
> > boot.config: -Dh ...", the logo screen, and then the login screen,  
> > during startup and *nothing* at all during shutdown. Also, I'm able  
> > to login and use the system both via the serial console and via the  
> > graphics card/keyboard... Is this supposed to be? I'm not  
> > complaining, I just got the impression it was one or the other.
> >
> > Any advice on how to get the kernel/rc messages etc. to the serial  
> > console (only or as well)?
> >
> > Regards,
> > Thomas
> OK, so to rule out any installation-related problems, I booted from a  
> bootonly install CD (a May ~5th snapshot of 8.0-CURRENT), with "boot - 
> h -S115200". Same thing: bootloader stuff on the serial console,  
> kernel messages on the local computer only - and very slowly, at that,  
> I'd say about one line a second. You could very easily see the  
> characters being written to the screen.
> 
> Am I the only one having these problems? It'd suck to buy a rather  
> expensive (probably because they're pretty rare these days, plus I had  
> to order from abroad) null modem cable and have it be completely  
> useless.
> 
> Regards,
> Thomas

you need to set
	hint.uart.0.flags="0x10"

danny




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