where is my serial device??? /dev/ttyS* is missing!

mrchaos · 03-10-2006, 09:22 PM

I have a serial port on my motherboard with whom I would like to communicate with a serial device. I have kernel 2.6.x and consequently my kernel utilizes udev. HOWEVER, when my computer boots up there is no /dev/ttyS* or /dev/tts/*... nothing! where the hell is my serial port and how can i fix this problem?

what scares me also is that my lspci output shows no trace of my serial bus:

Code:

root@ZAXCOMP:/# lspci
00:00.0 Host bridge: Intel Corporation 82875P/E7210 Memory Controller Hub (rev 02)
00:01.0 PCI bridge: Intel Corporation 82875P Processor to AGP Controller (rev 02)
00:1d.0 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #3 (rev 02)
00:1d.3 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #4 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev c2)
00:1f.0 ISA bridge: Intel Corporation 82801EB/ER (ICH5/ICH5R) LPC Interface Bridge (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801EB/ER (ICH5/ICH5R) IDE Controller (rev 02)
00:1f.2 IDE interface: Intel Corporation 82801EB (ICH5) SATA Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801EB/ER (ICH5/ICH5R) SMBus Controller (rev 02)
01:00.0 VGA compatible controller: ATI Technologies Inc Radeon R350 [Radeon 9800 Pro]
01:00.1 Display controller: ATI Technologies Inc Radeon R350 [Radeon 9800 Pro] (Secondary)
02:01.0 Ethernet controller: Atheros Communications, Inc. AR5212 802.11abg NIC (rev 01)
02:02.0 Multimedia audio controller: Creative Labs SB0400 Audigy2 Value
02:03.0 Multimedia video controller: Internext Compression Inc iTVC16 (CX23416) MPEG-2 Encoder (rev 01)
02:08.0 Ethernet controller: Intel Corporation 82562EZ 10/100 Ethernet Controller (rev 02)

My serial port is integrated into my motherboard

bigrigdriver · 03-11-2006, 10:55 AM

You can use the setserial command to get/set serial port parameters. In the man pages, get commands are listed first; then set commands.

Somewhere is /etc, there should also be a setserial script which you can edit to setup the serial device on boot.

Also, have you looked in /dev to see it ttyS0 is listed?

What output do you get from 'ls -l <device>'. For example, if I do 'ls -l /dev/modem', I get '/dev/modem -> /dev/ttyS0', meaning modem is linked to ttyS0.

mrchaos · 03-11-2006, 02:50 PM

it's not a modem that I'm using the serial port to connect with; it's my ipaq. ls -l /dev/ttyS* returns nothing, and that's where the problem begins. I can

Code:

cd /dev
mknod ttyS0 c 4 64

and this creates the device, but the device isn't actually linked to my serial port, it's just a virtual device linked to no physical hardware.

I tried using setserial to assign a specific IRQ range to my virtual /dev/ttyS0, but as you can see lspci lists no serial bus, so I was unable to determine which values to assign