devices refers to questions about the Unix/Linux device special files, normally these are under /dev. Do not use this tag for physical devices (for that use e.g. usb or pci).

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What happens if I run fsck on /dev/sda instead of /dev/sda1?

When I have run fsck in the past I have always run it on what I thought was a filesystem partition, ie. fsck -yf /dev/sdaN, where N is the partition number on disk A. A friend of mine recently ran ...
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0answers
14 views

How/where are linux device capabilities / bitfields set?

I have a device that has this output in /proc/bus/input/devices: I: Bus=0003 Vendor=05b8 Product=3280 Version=0111 N: Name="PixArt USB Optical Mouse" P: Phys=usb-0000:00:1a.0-1.1/input0 S: ...
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0answers
19 views

How can I mount the Logitech C270 in the zynq-7000 (with Linaro linux)?

I am doing camera control programming for a university project using zynq 7000. I want to mount the camera module that's for the Logitech C270 (like this ...
9
votes
2answers
466 views

Are there alternatives to using `udev`?

While I understand the greatness of udev and appreciate the developers' effort, I was simply wondering if there is an alternative to it. For instance, I might imagine there should be a way to make ...
1
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1answer
23 views

create several /dev/xconsole files

I am using /dev/xconsole to send system logs from rsyslog. That works great, because I am don't have to store the logs on disk. I would like to have another similar file , i.e /dev/xconsole1 where I ...
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0answers
11 views

How do you determine the capabilities of a WebCam?

I have a collection of WebCam's lying around. Some of them are new, some go back a decade (gotta love not having to "upgrade" devices in Linux :). Somehow I've developed the impression that ...
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0answers
19 views

Is the device tree compiler tied to the kernel version?

I have a situation in which same device trees are used with different kernels. Can the device trees be build only once and used with all kernels? The reason I ask this is because I found the device ...
3
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1answer
87 views

cannot create special file /dev/pts/0

When using midnight commander in console, I cannot "toggle" the window (using CTRL-o Not an xterm or Linux console; the panels cannot be toggled however, my $TERM is set to linux. After some ...
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0answers
14 views

character device file (rtai_shm) disappears under runlevel=5 in fedora9 (exists when runlevel=3)

I am trying to run Realtime (RTAI) on my Linux Fedora 9 machine. For that, it is needed to have a character device file, named rtai_shm, in /dev, that takes care of shared memory. I have made this ...
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0answers
8 views

unitek nec upd720200 not detected

I've decided to buy an USB3.0 controller on PCI for my debian machine. I did a short research and it appeared that NEC chips will be fine. I've bought Unitek NEC UPD720200 and I does not work: I ...
0
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1answer
31 views

Determine driver for network interface [duplicate]

I wanted to see which driver was associated with some of the network interfaces listed by ip link. My first thought was to find the network interfaces in /dev and look at the device major and minor ...
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1answer
37 views

USB 3G dongle internet keeps failing on Fedora 20 laptop

I use a 3G dongle for internet in my summerhouse, it has worked fine all summer, but since yesterday it has been losing connection, or something and I have to unplug it and insert it again for the ...
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3answers
23 views

Looking at the content of a character device's file [duplicate]

Why is it possible to look at the contents of a block device's file like /dev/sda using cat or a hex editor? Why can I not do the same for a character device like /dev/pts/3?
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1answer
47 views

How do I send RTSP video to a program that reads from a character device?

I have an IP-CAM that streams video over RTSP and I want to detect bar codes from it with zbarcam (from Ubuntu's zbar-tools package). According zbarcam's manual, it expects to be given a video4linux ...
3
votes
3answers
186 views

equivalent of `grep -a /dev/sda1` on Darwin?

I want to run something like % sudo grep -i -a 'some-string' <drive device> On Linux, <drive device> would be something like /dev/sda1. How can I find the equivalent on Darwin? (In ...
3
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2answers
75 views

Transfering content of block devices

For the purpose of backups, I'd like to transfer (several) whole disk partitions over an ssh link. So the source is a block special device, and the target should be a regular file. Common tools seem ...
4
votes
1answer
77 views

look up the device from its tty file?

Here is from my Ubuntu $ ls /dev/*tty* /dev/tty /dev/tty17 /dev/tty26 /dev/tty35 /dev/tty44 /dev/tty53 /dev/tty62 /dev/ttyS12 /dev/ttyS21 /dev/ttyS30 /dev/tty0 /dev/tty18 /dev/tty27 ...
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0answers
107 views

/dev/sda not appearing after secure erase

I decided to wipe my SSD with a secure erase before installing Arch Linux, since the Arch wiki said that it would improve performance. I followed the instructions listed on the wiki, but now when I ...
2
votes
1answer
20 views

PCI header in my laptop looks different from free-electrons' PCI header

I'm trying to develope a pci driver but I can not compile it because my pci header is quite different from books and references. My distribution is 3.15.7-1-ARCH. ...
2
votes
1answer
54 views

How can I set device rw permissions permanetnly on raspbian?

Im using Raspbian (distribution made for Raspberry Pi based on Debian). I have some scripts that use i2c. Normally only root has read and write permissions for i2c. Im using this command to add i2c ...
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0answers
14 views

Cross driver communication through sysfs or /dev/ [duplicate]

I have two drivers I'm developing. One needs information from the other. Is there anything wrong with one driver reading from the sys attribute / or read/write through /dev/drivername of the driver it ...
4
votes
1answer
118 views

Does Posix require any devices?

Does Posix require any devices? For example, /dev/urandom, /dev/zero or /dev/null? I suspect not because of non-*nix OSes, but wanted to ask for completeness.
4
votes
2answers
93 views

How to programatically detect when a device raises an interrupt?

How to programatically detect when a device raises an interrupt? This can be when a device is connected or disconnected. And also this case: for example: when a finger is held over a fingerprint ...
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0answers
24 views

Hotplug Device Driver Priority

Is it possible to have more than one driver for one purpose (eg. USB) included in the Linux kernel? If so, then how does the kernel decide which one to load?
1
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1answer
442 views

Prevent USB storage from using different device on reset

I have a hard drive in a USB enclosure that I am doing some data recovery on. The drive is in extremely bad shape and frequently resets on reads. The device registers as /dev/sdb. Sometimes, probably ...
2
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0answers
125 views

How to get device filename from lsusb output or by device path

Related question: USB connect/disconnect notification When the device is plugged/unplugged, I get instant notification, that's great. But to make it (almost) perfect, I also want to get device ...
2
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3answers
147 views

How to know if /dev/hda2 is Primary partition or Extended partition

If all four primary partitions exist on an IDE drive, they are numbered as follows: /dev/hda1 /dev/hda2 /dev/hda3 /dev/hda4 We have also the partitions on a disk with one primary partition and ...
1
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1answer
29 views

console (driver) not opening using any of the editor

In my initramfs, I have; [root@xilinx Peta_Microzed_15_05]# ls initramfs/dev/ console [root@xilinx Peta_Microzed_15_05]# nano initramfs/dev/console [root@xilinx Peta_Microzed_15_05]# The above ...
1
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1answer
229 views

Why isn't sda1 showing up in dev and how can I fix that?

I have an embedded Linux device and I was trying to copy some files to it. I plugged in a USB stick, the dmesg shows that it was recognized, but for some reason /dev/sda1 never showed up. I'm trying ...
2
votes
1answer
90 views

Can renaming a network device cause race conditions?

Arch uses predictable network interface names. MATLAB licenses are linked to the MAC address of eth0, so I need to rename one of my devices eth0. In a machines with only one NIC I can just turn off ...
0
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0answers
44 views

Best Practices for Configuring/Reading Sensor Devices

I have a gadget with a number of environmental sensors attached via an I2C bus, and would like to be able configure and read these sensors via an unprivileged application. Unfortunately, there ...
0
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1answer
67 views

Two Linux Mint 16 systems Skyping--one can see both parties on webcam, the other can see neither

I installed Linux Mint 16 32-bit edition on my netbook and a friend's laptop. When we Skype, I can see her live image, and I can see my own live image, so everything looks and sounds right on my end. ...
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0answers
25 views

information about txop in ath9k wlan driver

I'm trying to implement the rate control algorithm into ath9k wireless LAN driver. I need to find if the transmission of first packet in the TXOP has failed or succeeded (ack received or not). I ...
3
votes
2answers
86 views

what is the difference between Device driver and kernel module

i know that driver is a software that can communicate with the hardware in order to control the device that attached to the computer.whereas kernel module is a small piece of code that can inserted ...
9
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2answers
2k views

How can I find available network interfaces?

This is in regard to linux, but if anyone knows of a general *nix method that would be good. I booted a system yesterday with an ethernet cable plugged in. "NetworkManager" is not installed, so once ...
2
votes
2answers
97 views

Check if a drive has been Zeroed with xxd and uniq?

I'm looking for a way to check if the entire binary contents of a USB device are purely 0s. I'm trying this command: sudo xxd /dev/sdb | uniq but it has no output and just runs forever. I've ...
7
votes
1answer
103 views

How to find which serial port is in use?

The Question: I plugged in a device (i.e. GSM modem) through a serial port (a.k.a. RS-232), and I need to see with which file in /dev/ filesystem this device was tied up, to be able to communicate ...
0
votes
2answers
380 views

Can I change devices permissions with chmod?

Before read: I don't want to use any udev rule. I need to change (programmatically) the permissions of some device. But first in order to underestand what I have to do (in code) I want to make the ...
2
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0answers
79 views

Debian - cannot find cdrom

Having a jessie/sid debian box on kernel 3.13 (had same issue on kernel 3.10) First thing I notices was that k3b didn't find any optical drives. Then: The optical drives (dvd-writers) are found in ...
3
votes
1answer
111 views

How to get address of connected USB modem?

I just connected my N81 telephone as USB modem to Linux Mint 14. All works fine, just wondering how to find a full path to this device, something like /dev/tty*.
1
vote
1answer
61 views

Why does RTC device have 254,0 instead of 10,135 as Major,Minor numbers?

Why isn't /dev/rtc the well known "c 10 135" device that it's on x86, but a magic undocumented "c 254 0" device? Devices.txt lists this major number as LOCAL/EXPERIMENTAL USE. I'm working on a ...
2
votes
1answer
336 views

Is it possible to simulate/force/fake an USB device unplug and replug on Linux?

So I've got a strange problem that I've been running onto. I've got a bitcoin usb miner, Bitfury, and I'm using CGMiner to mine. When I start the application, as root, the USB device is not detected ...
0
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0answers
114 views

Editing a device tree to disable driver loading

Below is a section of device tree. ps7_ethernet_0: ps7-ethernet@e000b000 { #address-cells = <1>; #size-cells = <0>; ...
2
votes
1answer
78 views

What are the two values in < > in a device tree .dts file ?

Following is the code snippet in a device tree file: flash@0 { compatible = "n25q128"; reg = <0x0>; spi-max-frequency = <50000000>; ...
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4answers
2k views

Why does “cat ttyUSB0” not produce output?

I connected an infrared receiver to a USB port ... (the last line of dmesg tells device file) $ dmesg [10496.596063] usb 7-2: new full-speed USB device number 2 using uhci_hcd [10496.751112] usb 7-2: ...
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0answers
87 views

Why is my embedded Linux unable to detect the sd device?

I have this ARM9 SAM9G25 embedded System, running a Linux 2.6.39 Kernel and a Busybox. I put the Images (of the bootloaders, and the linux+initramfs) on a SD so that in the end the system is booting ...
5
votes
1answer
1k views

Difference between /dev and /sys/class?

What is the difference between the device representation in /dev between the one in /sys/class? Is one prefered over the other? Is there something one offers and the other doesn't?
3
votes
1answer
787 views

Is there a way to change device names in /dev directory?

I wrote this rule for testing purpose: SUBSYSTEMS=="usb", ATTRS{manufacturer}=="Kingston", ATTRS{serial}=="001CC0EC34A2BB318709004B", ATTRS{idVendor}=="0951", ATTRS{idProduct}=="1642", ...
3
votes
2answers
2k views

Unable to find root device / sda partitions missing

I have installed Archlinux, and after that GRUB. I manually entered menu entries for both my Windows and Arch installation. GRUB has no problems booting, and can successfully load in Windows. It ...
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2answers
88 views

What is a device tree and a device tree blob?

What exactly is a device tree, and a device tree blob? Where can I get its source code for a particular linux version? I found such name while running linux on xilinx chips (having ARM 9), for ...