does udev make /dev/ttyS0 ?

dansawyer · 10-23-2005, 09:40 PM

I am having problems making /dev/ttyS0 during startup. The physical device exists and the bios monitor reports it operational.

Where in the boot process is /dev/ttyS0 made?

udev is active and appears to make several devices. However I cannot determine exactly what it is doing.

Is udev supposed to make /dev/ttyS0?

Thanks, Dan

foo_bar_foo · 10-23-2005, 10:58 PM

I'm no expert on this by a long shot bt udev is suposed to be using the info in your sysfs
you got sysfs mounted in /etc/fstab ?

Code:

sysfs          /sys         sysfs  defaults        0     0

this should result in the kernel making a directory
/sys/class/tty/ttyS0
it should hhave a file in it named dev with the major and minor device numbers

should be able to type
udevinfo -q path -n ttyS0
and get
/class/tty/ttyS0

perhaps we can go from here and diagnose further

dansawyer · 10-23-2005, 11:16 PM

Thank you - great help. On one system where it works the result is as expected. On the other that fails it is:

device not found in database

This yields the question "what database".

There are files in "/etc/makedev.d" and one of those calls for ttyS0 however that device is not being created.

What portion of the boot process should create that device?
Is there a log entry and which one?

Thanks, Dan