After running make command, there will be one module:
- dummy-char.ko
After loading the module, there will be a /dev/dummy_char char device. There
is also a class created for this device, /sys/class/dummy_char_class/. One can
actually print info on the device using udevadm info command:
# insmod dummy-char.ko
# udevadm info /dev/dummy_char
P: /devices/virtual/dummy_char_class/dummy_char
N: dummy_char
E: DEVNAME=/dev/dummy_char
E: DEVPATH=/devices/virtual/dummy_char_class/dummy_char
E: MAJOR=241
E: MINOR=0
E: SUBSYSTEM=dummy_char_class
$ ls -l /sys/class/dummy_char_class/
total 0
lrwxrwxrwx 1 root root 0 oct. 12 16:05 dummy_char -> ../../devices/virtual/dummy_char_class/dummy_char
$ cat /sys/class/dummy_char_class/dummy_char/dev
241:0For testing purpose, one can use cat and read commands:
# cat /dev/dummy_char
# echo "blabla" > /dev/dummy_char
# rmmod dummy-char.ko
$ dmesg
[...]
[31444.392114] dummy_char major number = 241
[31444.392217] dummy char module loaded
[31452.575938] Someone tried to open me
[31452.575945] Nothing to read guy
[31452.575950] Someone closed me
[31483.210527] Someone tried to open me
[31483.210570] Can't accept any data guy
[31483.210578] Someone closed me
[31498.998185] dummy char module Unloaded