Advice on serial console configurations?

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Advice on serial console configurations?

Keith Wessel-3

Hi, all,


Hoping someone has more insight into serial console setup than me.


My current system has no on-board serial ports. I’ve been without Speakup since I moved to it. Not even headers for one. I’m looking for an excuse to by a new mother board.


In the meantime, I’ve got a SIIG PCI board in there that works fine. It’s driving my braille display with brltty just fine. Of course, it uses non-standard I/O addrs and IRQs. But brltty doesn’t care about that.


I recently got a docking station for my work Windows laptop that has a serial port, and this was my nudge to use the other port on my PCI serial card to set up a serial console that I can access from Windows. Keeps me from having to get my wife to read the screen to me every time my system won’t boot far enough for brltty.


When I add:


console=ttyS0,9600n8 console=tty0


to my kernel command-line, I get nothing in my terminal program on the laptop. I know the connection’s working because agetty gives me a login prompt and allows me to log in once the system is booting.


What does happen with the console parameters added to the kernel command-line different from without them is that the system boots very slowly. Takes more like 10 minutes instead of the usual 1 minute to get to a login prompt.


Is this because my serial ports are using non-standard I/O ports and IRQs? Or is Linux smart enough to not assume anything about those? Clearly something’s getting it right since the right parameters are getting set once the system has booted and brltty starts.


Can anyone think of any other explanations? Or is it time to buy a new mother board?