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1answer
148 views

How to debug a device that changes from /dev/ttyUSB0 to /dev/ttyUSB1 at will?

I have a device plugged to a CentOS server that changes randomly from /dev/ttyUSB0 to /dev/ttyUSB1 and vice versa. The device I'm trying to connect is this one. How can I debug this?
1
vote
1answer
240 views

Difference between Device file and device drivers

I am beginner in device driver programming. I don't get the difference between device drivers and device files in Linux. Can anyone explain the difference?
0
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0answers
234 views

What are high level and low level device drivers

Recently I read that there are two types of drivers (at least for disk), one that are called high level drivers and another called low level device drivers. Can some one tell me what these are, and ...
1
vote
1answer
91 views

2 or more programs in same USB serial converter

Having a network of lets say 10 devices in RS-485, connected to the linux PC with a RS-485 to USB Converter. Already there is a C program interacting with the serial converter at /dev/ttyUSB0. My ...
1
vote
0answers
63 views

Which Unixes support cross-device filesystem links (in particular for rename)?

Just read the following on the FreeBSD man page for the rename syscall: ... [EXDEV] The link named by to and the file named by from are on different logical devices (file systems). Note that ...
1
vote
0answers
340 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 ...
4
votes
2answers
121 views

Can you identify transport via sysfs?

I'm writing a script, and I'm interested in being able to identify the transport class (fc - "fibre channel", scsi, iscsi, etc.) for a given block device. I can retrieve this information via ls -l ...
3
votes
2answers
155 views

Permissions to print directly to USB printer

I've a netbook with Linux. I've a usb/serial printer and I added the line chmod 666 /dev/tty* to rc.local and it prints straight after a reboot. When I close the lid of a netbook for a while and then ...
2
votes
0answers
84 views

How to rename devices for graphical output such as VGA0

On my Laptop the names of my graphical outputs change depending on what chip is activated in the BIOS. This leads to problems in some scripts where outputs such as VGA-0 or LVDS-0 are specified. So I ...
6
votes
3answers
3k views

what is stored in /dev/pts files and Can we open those?

I am curious to know that what is stored in /dev/pts/ files . Can we open those files ? According to my knowledge /dev/pts files are created for ssh or telnet session .
2
votes
1answer
765 views

Unable to use busybox implementation of hwclock

I have a buildroot generated kernel (3.6.11) and root file system running on an x86 device. It uses busybox and I am trying to set the BIOS hardware clock using hwclock. I get this error whenever I ...
0
votes
1answer
74 views

Random bug in Linux

Some time ago, I remember reading an article on randomization in computing, and how random you can actually get a system to be. The article came about, if I'm not mistaken, because of some seemingly ...
0
votes
2answers
108 views

ECC on a single block device

I have an SSD that I suspect failing silently now and then. I have run badblocks on it and it is clear that it is not bad sectors but might instead be some race condition in the electronics, in which ...
1
vote
0answers
246 views

udev Unable to Rename Network Device: Device or Resource Busy

I'm trying to use udev rules in order to give my network interfaces static, consistent names. However, it seems like there is some race condition happening preventing these rules from consistently ...
0
votes
2answers
132 views

IO utilization for /dev/null redirection?

I always use nohup to start my system. However, the output to nohup is so big that I'm thinking to redirect it to /dev/null. My concern is, will redirecting to /dev/null also incur some I/O operations ...
2
votes
1answer
130 views

GPS Device Attached to Linux Mint 15

I purchased a Silvercrest GPS device from Lidl recently, but the software that came with it is a tad "underpowered" to say the very least and has no Linux support. I'm attempting to get at the raw ...
1
vote
1answer
547 views

“Permission denied” when writing to /dev/stdout

Why cannot I write to /dev/stdout? I am logged in as the root user, what greater permission could I have? root@ubuntu:/# tcpdump -i 2 -w /dev/stdout tcpdump: /dev/stdout: Permission denied The ...
3
votes
1answer
306 views

Udev rule to match multiple node USB device

I have a 3G/GPS device that creates 5 tty nodes, although it's only one physical USB connection. Basically, a multi port usb-serial adapter. I'm trying to create some udev rules to make sure those ...
1
vote
1answer
587 views

Beaglebone Black Device Tree for LCD4 cape

The device tree for LCD4 cape is located at /lib/firmware/BB-BONE-LCD4-01-00A1.dts When I looked into it, the declaration of those GPIO buttons confuse me. There are five buttons according to ...
2
votes
1answer
427 views

ffmpeg webcam to device driver , output 8 bit grayscale

With the following command i'm trying to capture 10fps and send them the device driver. Now i want 8 bit gray raw frames (640x480= 307200 bytes per frame) to be send to the device driver. I can't ...
3
votes
2answers
1k views

/dev/hidraw: read permissions

What do I need to do to have read permissions on /dev/hidraw*? I'm seeing stuff about udev rules and saw this on the net, but the world of udev is like a foreign land to me, and if there's some sort ...
1
vote
0answers
92 views

Any good usb-serial (RS485) adapter to use with GNU/Linux?

I'm having problem with usb-serial (RS485) adapters. Firstly, I tried ch341 without success. The problem in this case is the linux driver, made by reverse engeneering (sadly without any help from the ...
4
votes
2answers
402 views

How to take sha-1, sha-256 or MD5 of CDs / DVDs?

I just tried burning both a Debian CD and a Debian DVD from their .iso files and I've got a weird behavior: the checksum of the CD is correct but the one of the DVD ain't. Here's what working: ...
2
votes
2answers
1k views

What is a device controller, and where does it fit in between the kernel and the device?

Can someone please explain the concept of a device controller (hard disc controller, NEC PD765 compatible controller etc.). Here are some definition of key terms which might be needed for the ...
1
vote
1answer
228 views

dd outputting: “function not implemented” when trying to write to /dev/sg11

I'm trying to use the following command: dd if=/dev/urandom of=/dev/sg11 bs=16K count=1 But when executing it, I get the following error: dd: writing `/dev/sg11': Function not implemented When I ...
1
vote
1answer
71 views

Need list of HDD devices excluding my os HDD

I want list out whole HDD device excluding my os running device attached to my system. I did lot's of googling and fired many more commands in command line of linux. but can't gating proper output. ...
3
votes
1answer
267 views

How to get the actual keyboard device given the output of /proc/bus/input/devices?

When I run: cat /proc/bus/input/devices ...I receive the following output: ... I: Bus=0003 Vendor=040b Product=2000 Version=0110 N: Name="Generic USB Keyboard" P: Phys=usb-0000:00:1d.0-1/input0 ...
1
vote
2answers
235 views

Meaning of “target” in virsh XML VM definitions.

I recently found that the target=hda tag in virsh was actually not translating into guest OS (guest OS's use /dev/sdX as the disk device names, in general, it seems). virt-install and /dev/hda vs. ...
1
vote
2answers
529 views

virt-install and /dev/hda vs. /dev/sda

It appears that my virt-install xml file (i.e. created when defining a VM) specifies targets "hda", "hdb", and so on as the devices for disks, however, the VM, once created, lists /dev/sda, /dev/sdb, ...
3
votes
1answer
297 views

Why are devd rules applied before devfs rules?

My problem I have the following lines in /etc/devd.conf which execute the usbhidaction for a /dev/uhid* device with the named vendor and product id. attach 100 { match "vendor" "0x046a"; ...
0
votes
2answers
610 views

Cheap 100% Debian compatible ultrabooks [closed]

I'm looking for relatively cheap ultrabooks with 100% Debian compatible features. I have several ultrabooks on my list but they contain some additional features which i don't need (additional ...
4
votes
1answer
533 views

Find out if a specific device is an USB mass storage

Context I'm automating SD card imaging from an existing dd factory image. The SD card is always connected through an external USB card reader and thus appears in the system as a SCSI block device ...
1
vote
0answers
342 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: ...
2
votes
1answer
927 views

“PS/2 Generic Mouse” gets lost. How to reload without reboot?

I am running Ubuntu 12.04LTS on a ThinkPad E420s. My Trackpoint is recognized as "PS/2 Generic Mouse". My problem is that it doesn't load/disappears after booting or after suspension. I can't move ...
5
votes
2answers
231 views

Can I query which processes (if any) are currently accessing the microphone?

I'm running Debian (technically Raspbian), trying to get a Star-Trek style voice-command system. I've got it mostly up and running, but in the interests of privacy and all that jazz, I don't want my ...
2
votes
1answer
58 views

Assigning static device path

I have 4 flash cards plugged in, sequentially named by system: /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 I want to assign static pathes to them, so every time the system boots up their pathes will ...
-1
votes
1answer
187 views

what type of device drivers are available in linux [closed]

The different types of device drivers used in linux are character device and block device. Is there another classification?
2
votes
2answers
168 views

Detecting the device of a crypto mount

I have an external eSATA-hdd on an OpenSUSE 12.2 system. The external hdd has an LVM on a dm-crypt partition. I mount it by powering it up and then doing rescan-scsi-bus.sh cryptsetup -v luksOpen ...
1
vote
1answer
1k views

pvcreate error on partition

I can't create this partition, I'm getting this error shown below: Device /dev/mapper/vg_paperino-lv_rootp1 not found (or ignored by filtering) Below are the steps that I'm doing on CentOS: ...
6
votes
1answer
4k views

using devtmpfs for /dev

I have noticed the following option in the kernel: CONFIG_DEVTMPFS Device Drivers -> Generic Driver Options -> Maintain devtmpfs to mount at /dev And I see that it is enabled by default in ...
3
votes
2answers
806 views

Can I stop Linux from listening to a USB input device as a keyboard, but still capture events with a program?

I have a USB barcode scanner at /dev/input/event0 (/dev/input/by-id/usb-Metrologic_Metrologic_Scanner-event-kbd), and scanning a barcode causes it to send keypress events. I'm capturing these ...
1
vote
1answer
200 views

Creating a terminal device for interprocess communication

I'd like to know how to create a terminal device to simulate a piece of hardware connected through a serial port. Basically, tty device with a certain baud rate that can be read from and written to ...
1
vote
1answer
405 views

Installing a platform driver

I have recently acquired a device driver for an integrated watchdog timer on a x86 board on which I am running a minimal Linux system. The kernel is 3.6.11 and it has been built using buildroot. My ...
4
votes
4answers
809 views

Special File that causes I/O error

I want to automatically test if a piece of software reacts as expected if an essential SQLite DB file fails to be read (causing an I/O error). Exactly that happened some days ago at a client. We ...
3
votes
2answers
265 views

Why doesn't `head -c 2 /dev/hwrng` work?

I have an Atmel 97SC3201 in my computer and set the following in the kernel: CONFIG_HW_RANDOM_TPM CONFIG_TCG_TPM CONFIG_TCG_ATMEL /dev has tpm0 and hwrng, but running this command returns the ...
5
votes
3answers
3k views

RHEL: Creating stable names for network interfaces

We have a RHEL 5.5 box with 8 interfaces. And the eth interface naming is flip flopping. Sometimes eth0 comes up on physical port 7th, and sometimes on another physical port. We want the naming to ...
1
vote
2answers
144 views

/dev/console points to tty0?

I've been trying to understand the /dev/console device, but there are a few things I'm not clear on: What is the purpose of this device? From what I can gather it's just a place for the kernel to ...
4
votes
1answer
828 views

Explain EV in /proc/bus/input/devices data

Can anybody explain to me what the EV value in /proc/bus/input/devices is? The keyboard always has value 120013. Why?
2
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0answers
72 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 ...
3
votes
2answers
2k views

Creating eth0 with consistent network device naming

From my understanding, Arch Linux uses Consistent Network Device Naming where the network devices are no longer named eth0, eth1, etc. I use the proprietary MATLAB software which requires a device ...