字符设备驱动之/proc/devices和/dev的关系

/proc/devices/下的设备是驱动程序生成的，它可产生一个major供mknod作为参数。

/dev/下的设备是通过mknod加上去的，用户通过此设备名来访问驱动。

The following script, scull_load, is part of the scull distribution. The user of a driver that is distributed in the form of a module can invoke such a script from the system's rc.local file
or call it manually whenever the module is needed.
#!/bin/sh

module="scull"

device="scull"

mode="664"

# invoke insmod with all arguments we got

# and use a pathname, as newer modutils don't look in . by default

/sbin/insmod ./$module.ko $* || exit 1

# remove stale nodes

rm -f /dev/${device}[0-3]

major=$(awk "\\$2= =\"$module\" {print \\$1}" /proc/devices)

mknod /dev/${device}0 c $major 0

mknod /dev/${device}1 c $major 1

mknod /dev/${device}2 c $major 2

mknod /dev/${device}3 c $major 3

# give appropriate group/permissions, and change the group.

# Not all distributions have staff, some have "wheel" instead.

group="staff"

grep -q '^staff:' /etc/group || group="wheel"

chgrp $group /dev/${device}[0-3]

chmod $mode /dev/${device}[0-3]



请 问:linux环境下,/dev/目录下的内容与/proc/下文件devices中的内容有什么区别?我在目标板上做实验时发现,当我向板子上加载驱动 模块时,devices文件中有变化,而/dev下根本没有变化,/dev/下不也应该是设备接点吗,为什么为模块建立设备接点时,/dev/下却没有变 化呢?

请各位帮帮忙,谢谢!!!

/proc/devices/中的设备是通过insmod加载到内核的，它可产生一个major供mknod作为参数。

/dev/*.* 是通过mknod加上去的，格式:mknod device1 c/b major minor 如：mknod dr1 c 254 0，用户通过此设备名来访问你的驱动。