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I have debian6.0 installed on my machine. It has four comports of which 2 cannot be found. From looking that the systems bios I can see that the ports address are:

1         3F8          4
2         2F8          3
3         3E8          10
4         2E8          11

Ports 1 and 2 are found by debian but 3 and 4 are not. From what I understand I can setup the ports with this information using setserial. I tried:

setserial /dev/ttyS2 port 0x03e8 irq 10 baud_base 115200

but I recieve:

/dev/ttyS2: No such file or directory

Is it safe to create a file in /dev named ttyS2? and try to run the same command again?


As per jordanm's request:

# cat /proc/devices
Character devices:
  1 mem
  2 pty
  3 ttyp
  4 /dev/vc/0
  4 tty
  4 ttyS
  5 /dev/tty
  5 /dev/console
  5 /dev/ptmx
  7 vcs
 10 misc
 13 input
 29 fb
128 ptm
136 pts
180 usb
189 usb_device
253 rtc
254 hidraw

Block devices:
259 blkext
  7 loop
  8 sd
 65 sd
 66 sd
 67 sd
 68 sd
 69 sd
 70 sd
 71 sd
128 sd
129 sd
130 sd
131 sd
132 sd
133 sd
134 sd
135 sd


so I made the device file with:

mknod -m 666 /dev/ttyS2 c 4 66

Than I tried to setup the com-port with:

setserial /dev/ttyS2 port 0x03e8 irq 10 autoconfig

but recieved:

/dev/ttyS2: No such device or address

There is in fact hardware for two additional serial ports.

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dev files must be made with mknod. Show the output of cat /proc/devices – jordanm Apr 12 '13 at 14:23
@jordanm I updated question with requested information – Richard Apr 12 '13 at 15:13
it's Baud rate, not Boud rate. – BatchyX Apr 12 '13 at 16:29
@BatchyX I know but thats how it is spelled in the bios.... :S – Richard Apr 12 '13 at 16:30
If the BIOS's ACPI tables are as botched as their spelling, i would suggest updating it. – BatchyX Apr 12 '13 at 16:43

in the grub bootloader I have parameter 8250.n_uarts = 4 to the boot line. After that I was able to setup serial ports using setserial

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