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Questions tagged [devices]

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).

5
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0answers
3k views

How do I find out the device node corresponding to my device in SuSE 8?

I'm forced to work with a bunch of point-of-sale systems running SuSE 8. They are my client's computers. We are stuck dealing with these old systems until they get to upgrade their whole fleet to SLE ...
4
votes
0answers
215 views

Modem's GPS data is piped to wrong device

I have a SIM7100E modem running on 4.8.0-26-generic which specifies the following devices: /dev/ttyUSB1 : NMEA port for GPS NMEA data output /dev/ttyUSB2 : AT port for AT commands Connecting to ...
3
votes
0answers
53 views

Debugging in android chrome as a non-root user

I am trying to debug a website displayed in Google Chrome on an Android device connected to my box via USB. To this end, there is the remote debugging protocol as implemented in the desktop versions ...
3
votes
0answers
312 views

Loading a kernel module at run time using “compatible” property of device node in device-tree

If I know the "compatible" property string of a device(from the device tree), can I use it at runtime to load the corresponding kernel driver module? I do not have access to the driver source. I am ...
3
votes
0answers
133 views

simultaneous mounts of devpts

I want to create multiple chroot environments, but I faced the issue with mounting devpts Here is STR: > mkdir -p {1,2}/{proc,sys,dev/pts} > mount -v -t sysfs sysfs 1/sys/ > mount -v -...
3
votes
0answers
396 views

/dev directory; characteristic device files: network_latency, network_throughput

I'm using some networking devices for car to car communication which runs on Linux 3.10.17 OS. With those devices I've to measure the overall network throughput and latency. Inside the /dev directory, ...
3
votes
0answers
60 views

Enumerate valid values for mknod

I have access to an embedded device which has a bunch of block/char files under /dev. However, this is not a satisfying description of the hardware, because since the firmware is shared with small ...
3
votes
0answers
673 views

Bluetooth keyboard not showing up in /dev/input

I've just installed an Apple Wireless keyboard on a Debian system. I used this guide and only console tools — no X on that machine yet. The keyboard works fine. Now I want to remap a right Cmd key ...
3
votes
0answers
88 views

Is there support for flattened device tree in Sparc 32 port of the Linux kernel?

We are trying to write a minimal bootloader for booting the linux kernel on a Sparc V8 processor simulator. From what I understand, the interface between the bootloader and kernel consists of a data ...
3
votes
0answers
143 views

Bad/strange USB device issue: failed to shutdown/restart

On a fresh Arch Linux installation with Intel i7 processor and an Nvidia graphics card, I noticed during boot log messages related to a usb device filled the screen before it reached the graphical ...
3
votes
0answers
3k views

Check if Keyboard and Mouse are plugged in

Is there a way to detect if a keyboard and a mouse is plugged in (and working) in Linux? This will be embedded in a PXE setup, so I only have Kernel + Modules and Busybox available. Bonus question: ...
3
votes
0answers
367 views

How to route one video device to multiple programs

I'd like to direct the output of a single capture card (Hauppauge PVR-150) to two programs: VLC (for streaming on LAN) and MythTV for scheduled recording. I think it's possible to do this with the ...
3
votes
0answers
858 views

How to know the event by looking at /dev/input/by-id

I want to access the keyboard device driver. I usually accesses it by looking at /dev/input/by-name but the event provided by it gets changed every time I log in. After searchin on the Net, I found ...
2
votes
0answers
108 views

systemd-nspawn: how to allow access to all devices?

I'm trying to create a rough equivalent of Docker's --privileged in a systemd container, but I've got no idea how to allow the container to access all of the devices available on the host (without ...
2
votes
0answers
31 views

how to fix the devices name ordering in guest vm (devices name ordering changed after reboot vm by virsh)

my devices xml define: first vm only has a root volume, <disk type='file' device='disk' snapshot='external'> <driver name='qemu' type='qcow2' cache='none'/> <source file='/dev/...
2
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0answers
36 views

Webcam and Desktop composite with v4l2loopback?

Is there anyway to do a composite video setup where the webcam is overlain onto the desktop and output as a video device (simulated webcam)?
2
votes
0answers
349 views

What is the difference between `/dev/input/event*` and `/dev/input/mouse*` according to mouses?

Suppose my mouse is associated to /dev/.../event1 and /dev/.../mouse1. I was reading the byte streams of those files, and I noticed that event1 gives much more information than mouse1, which ...
2
votes
0answers
366 views

Accessing I2C slave devices that are specified in Device Tree

I'm trying to communicate with a device over I2C from my BeagleBone Black, and I'm a bit curious as to the device tree's interpretation of I2C. I see that there are a couple of device nodes within ...
2
votes
0answers
521 views

/dev/random entropy on readonly file system

My hostapd works very well on my raspberry Pi3. But if I put root filesystem in readonly, it does not work. I have put some folders like /var/run and /tmp in a ramdisk filesystem. I have seen ...
2
votes
0answers
453 views

Why does md5sum give inconsistent results on device files?

Backing up some USB flash-drives on Lubuntu 16.04.3 LTS. Plug USB drive into laptop. Automounter does its stuff. I remount all partitions as read-only sudo mount -o remount,ro /dev/sdxn Copy USB ...
2
votes
0answers
827 views

Lenovo yoga 510 touchscreen not working

I just got a Lenovo Yoga 510. I've installed Fedora 25 (as dual boot with MSWindows). But the touchscreen isn't working in Wayland nor Xorg. xinput list only shows the trackpad, keyboard, powerbutton ...
2
votes
0answers
429 views

Ethernet to USB adapter is not initialized as ttyUSB or ttyACM device

When I plug a Ethernet-to-USB adapter to my Ubuntu 14.04 on the USB port. I can see the Ubuntu has an extra ethernet device. However, I want to see /dev/ttyACM* type of device. I'm wondering why the ...
2
votes
0answers
864 views

when running `udevadm test`: `no db file to read /run/udev/data/+gpio_sw:PA7: No such file or directory`

I am trying to write an udev rule that matches a GPIO Pin of my Orange Pi (the GPIOs use the gpio-sunxi kernel module). My ultimate goal is to let users who are member of a particular group access ...
2
votes
0answers
982 views

udev: Passing parameters via $attr{key} does not work. How to solve it?

I want to enumerate my USB-UART bridges with my own script. The script shall be called with some attributes and return a new devfs node name. I tested the script on console: ./rc3e.py -d get-devfs-...
2
votes
0answers
862 views

Why reading from and writing to framebuffer shows no effect ?

I read a very short description of how to make a Screenshot by making use of the file which represents the framebuffer /dev/fb0. in order to write the screen content: cat /dev/fb0 > file in ...
2
votes
0answers
782 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: Sysfs=/...
2
votes
0answers
596 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
0answers
376 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 ...
2
votes
0answers
737 views

Debian Wheezy USB2 ehci_hcd

I have a friend who decided to switch to Linux from Windows. I was helping her to get up and running as quickly as possible but we ran into a problem which I can't seem to solve. She uses Debian ...
2
votes
0answers
165 views

How to know when a device is ready

I have firewire mixing console and I wrote an udev rule which calls a script to set up the whole audio chain (alsa -> pulseaudio -> jackd -> firewire) as soon an the console is switched on. Now I ...
2
votes
0answers
321 views

Block Devices & Partitions

I partitioned a microSD card (mmcblk1) into two partitions mmcblk1p1 and mmcblk1p2. If use a dedicated card reader I am able to see the entire SD card and its partitions using various disk management ...
2
votes
0answers
301 views

Connected Android device - brings the network down?

I have dealt with sensitive development under Android, and have recently decided to switch to Linux now sit under (Mint 13 - KDE). But strangely, when the Android device is connected, my network goes ...
2
votes
0answers
67 views

Limiting write rate of a device

How does one go about limiting the write/read rate of a device, E.G., USB drive, SD card? Motivation behind this question is covered here (superuser.com).
1
vote
0answers
129 views

How to script AT command to modem?

Every time my USB modem (/dev/dlinkModem) gets unplugged it defaults to "radio disabled mode" (AT+CFUN:4). I can easily enough call AT+CFUN:1 through the minicom application console to enable radio ...
1
vote
0answers
117 views

When i plug in usb camera i get 2 devices

When I plug in the camera to Linux then I get 2 devices /dev/video0 and /dev/video1 Why is that happens and is that normal? Odd numbered devices do not work. /dev/v4l/by-path looks like that: ...
1
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0answers
25 views

Can I refer to current clipboard content as a file?

I'd like to select-and-copy some text to clipboard and then to send it via Bluetooth to my phone. But this requires to open a file to send. Well, I know about programs like xsel or xclip, but here it ...
1
vote
0answers
73 views

Is there any standard for naming RS-485 tty devices/device aliases in Linux?

I know, that there are some standards in tty naming. There is ttyUSBx for USB to serial converters, ttySx for RS-232, ttyAMAx on ARM devices, but I can't find anything about conventions in RS-485 ...
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vote
0answers
22 views

Scenario to use the sg driver

Is there any device commonly controlled by SCSI generic driver (sg) in Linux today? I am curious about that. Currently I just know the mtx tool which controls robots in tape libraries via sg driver.
1
vote
0answers
52 views

How can I xor two block devices together?

I'm looking for a way to create a virtual block device that when accessed returns the XOR of two block devices. I feel like dmsetup would be used here somewhere but I can't find anything related to ...
1
vote
0answers
25 views

Ethernet malfunction when booting with extra device on /dev

I have a customized Linux distro (created via buildroot) running on an embedded platform. The system consists in a processing module (Based on Samsung Exynos 4412 microprocessor) with a base board for ...
1
vote
0answers
35 views

Drive emulation at driver level

I would like to emulate a virtual SED at driver level. The goal is to develop/simulate the "firmware" of a drive, and map driver interface commands to an app which would handle interface specific ...
1
vote
0answers
154 views

Proxmox Guest: Network Device not linked

I've setup a new Ubuntu 18.04 virtual machine using Proxmox. On this new virtual machine I can't get a working Internet connection. The command lshw -C network shows: root@web:~# lshw -C network *-...
1
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0answers
953 views

How to get the specific serial port on usb-serial hub in Linux

I have a Linux machine with a connected USB hub (5 ports), and I also have a serial hub (8 serial ports) connected to this USB hub. It looks as follows: Linux -> usb hub -> usb-serial hub -> serial ...
1
vote
0answers
118 views

Identify device by its handler

I'm looking for a robust method for identifying a device's type (mouse, keyboard, joystick) by its input event handler. There are parameters which cannot be trusted, such as device name/vendor-id etc....
1
vote
0answers
51 views

How to mount a drive to a location that does not exist?

When I insert a drive, it automatically mounts to /media/homeuser/drivename. If I unmount it, I can always remount it by clicking the device again, and it remounts to the exact same spot. However, ...
1
vote
0answers
301 views

Remove extra non-working scanners

I tried to add a USB scanner to my system without any luck and now when I start XSane or Image Scan! for Linux I get a list of non-working scanners. How these can be removed? I've tried: # pacman -...
1
vote
0answers
537 views

Accessing a serial device from LXC guest

I have a Fedora 26 host running a privileged Ubuntu 16.04 guest in an LXC container. My goal is to connect to a serial device (/dev/ttyACM0) from the LXC guest. I created the guest OS with the ...
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0answers
816 views

How can I set device rw permissions permanently on ubuntu 16.04?

I am using an embedded device that is running ubuntu. Normally only root has read and write permissions for i2c devices. I'm using this command to add i2c r/w permissions for normal user (me): sudo ...
1
vote
0answers
1k views

How do I determine the cause of a SCSI device reset?

I found this in /var/log/messages: Jul 27 03:59:46 localhost kernel: sd 3:0:1:0: [sdd] SCSI device reset on scsi3:1 I don't see any other error logs to indicate why the reset occurred. How do I ...
1
vote
0answers
27 views

Creating a script that 'restarts' usb devices

I'm using my RasPi as a media center with the media stored on an external HDD. Now the problem is that the HDD crashes sometimes, usually one or a few times a week. When this happens the drive is '...