AnsweredAssumed Answered

Unable to list device node under /dev

Question asked by krish on Nov 30, 2011
Latest reply on Dec 1, 2011 by krish

Hello there,

 

I have been trying to list my device under /dev for but did not find any luck. I have written a small kernel loadable module ( LED_driver.ko)

After doing insmod i am able to find the module entry in sysfs.

 

root:/> version

kernel: Linux release 3.1.0-ADI-2012R1-pre, build #28 Wed Nov 30 18:44:08 IST 2011

toolchain: bfin-uclinux-gcc release gcc version 4.3.5 (ADI-2010R1-RC4) user-dist:

release 2010R1, build #1 Fri Nov 25 15:30:22 IST 2011

 

Loading the module

------------------

root:/> insmod /home/LED_driver.ko

LED driver is added with major number = 254

 

 

sysfs

------

root:/> ls /sys/module/LED_driver/

holders initstate refcnt sections uevent

 

procfs

------

root:/> cat /proc/devices

Character devices:

1 mem

4 /dev/vc/0

4 tty

5 /dev/tty

5 /dev/console

5 /dev/ptmx

7 vcs

10 misc

13 input

89 i2c

90 mtd

128 ptm

136 pts

204 ttyBF

254 LED_driver

Block devices: 1 ramdisk 259 blkext 31 mtdblock 43 nbd

root:/> ls /dev/
bfin-dma nbd8 tty21 tty5
bfin-otp nbd9 tty22 tty50
console network_latency tty23 tty51
cpu_dma_latency network_throughput tty24 tty52
full null tty25 tty53
i2c-0 ptmx tty26 tty54
kmsg pts tty27 tty55
mem ram0 tty28 tty56
mtd0 ram1 tty29 tty57
mtd0ro ram2 tty3 tty58
mtd1 ram3 tty30 tty59
mtd1ro ram4 tty31 tty6
mtd2 ram5 tty32 tty60
mtd2ro ram6 tty33 tty61
mtdblock0 ram7 tty34 tty62
mtdblock1 random tty35 tty63
mtdblock2 tty tty36 tty7

 

I have followed the below links

http://docs.blackfin.uclinux.org/doku.php?id=uclinux-dist:dev-management

http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:hotplug

http://docs.blackfin.uclinux.org/doku.php?id=uclinux-dist:mdev


root:/> echo /sbin/mdev > /proc/sys/kernel/hotplug
root:/> mdev -s

root:/> ls /dev/
bfin-dma nbd8 tty21 tty5
bfin-otp nbd9 tty22 tty50
console network_latency tty23 tty51
cpu_dma_latency network_throughput tty24 tty52
full null tty25 tty53
i2c-0 ptmx tty26 tty54
kmsg pts tty27 tty55
mem ram0 tty28 tty56
mtd0 ram1 tty29 tty57
mtd0ro ram2 tty3 tty58
mtd1 ram3 tty30 tty59
mtd1ro ram4 tty31 tty6
mtd2 ram5 tty32 tty60
mtd2ro ram6 tty33 tty61
mtdblock0 ram7 tty34 tty62
mtdblock1 random tty35 tty63
mtdblock2 tty tty36 tty7

 


Still not able see the device node under /dev

 

Any pointers?

 

Thanks in advance

Krish

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