Specialized software that runs inside the kernel.

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19
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5answers
5k views

What is the difference between kernel drivers and kernel modules?

When I do a lspci -k on my Kubuntu with a 3.2.0-29-generic kernel I can see something like this: 01:00.0 VGA compatible controller: NVIDIA Corporation G86 [Quadro NVS 290] (rev a1) Subsystem: ...
17
votes
1answer
8k views

How to assign USB driver to device

This question is two-fold: First, how do you manually detach a driver from a USB device and attach a different one? For example, I have a device that when connected automatically uses the ...
13
votes
3answers
205 views
+100

How to find the driver (module) associated with a device on Linux?

On Linux, given: a device, for example /dev/sda, and its major and minor numbers, for example 8, 0, how can I know which module / driver is "driving" it? Can I dig into /sys or /proc to ...
8
votes
3answers
4k views

Mount printers at /dev/usb and still use CUPS

Due to a new version of CUPS, I suddenly lost the direct path to my printers that was previously available under /dev/usb/lpXXX. I used this to print directly from the command line. echo "test" > ...
6
votes
4answers
13k views

Determining cause of Linux kernel panic

I'm running an Ubuntu 12.04 derivative (amd64) and I've been having really strange issues recently. Out of the blue, seemingly, X will freeze completely for a while (1-3 minutes?) and then the system ...
6
votes
2answers
2k views

How do I debug a kernel module in which a NULL pointer appears?

I have a custom kernel module that I compiled from this patch that adds support for the logitech G19 keyboard among other G series devices. I compiled it just fine against Ubuntu's maverick kernel's ...
6
votes
1answer
297 views

How to disable keyboard?

Without unplugging my keyboard I'd like to disable it from the terminal; I was hoping that this could be done using rmmod but based on my currently loaded modules it doesn't look like it is possible. ...
6
votes
3answers
2k views

Linux Kernel logical address space organisation

According to "Write Great Code" in almost all OS run time memory is organized into following regions: OS | Stack | Heap | Text | Static | Storage/BSS [In increasing address fashion] User ...
6
votes
1answer
165 views

How's a module approved to be included into the linux kernel?

I'm now compiling the linux kernel 2.6, and finding there are more than 1,000 modules in total. How is a module approved to be included into the linux kernel?
6
votes
2answers
1k views

How to block loading kernel module only in single user boot when blacklist fails?

On a "Linux debian 2.6.32-5-amd64 #1 SMP" installation where loading a kernel module (mpt2sas) is desired to be delayed to be loaded after starting sshd and users can remotely login, the mpt2sas ...
6
votes
1answer
3k views

Webcam on Angström

I am running Angström on my BeagleBoard-xm. I want to use a webcam (I have Microsoft LifeCam Cinema and Logitech C310). I installed v4l-utils, libv4l-dev and kernel-module-uvcvideo with opkg. But the ...
6
votes
2answers
1k views

What does mkinitrd change when it adds kernel modules to the initrd?

When creating an initrd using mkinitrd (CentOS 5.5), the kernel modules it adds to the initrd get modified in the process. For example, the initrd's /lib/sata_via.ko is not binary identical to ...
6
votes
1answer
472 views

Grubby fatal error in Linux kernel installation

I have compiled Linux kernel 2.6.24.6 from source (without problem) and tried to install it. Specifically, after unpacking the Linux source code, I did make && make modules to compile. ...
5
votes
4answers
2k views

Best way to get into Kernel programming?

Not so much asking what books (although if you know of any guides/tutorials that'd be helpful) but what is the best way to start doing kernel programming and is there a particular distro that would be ...
5
votes
1answer
114 views

Linux: What is a tainted kernel?

Under certain conditions, the Linux kernel may become tainted. For example, loading a proprietary video driver into the kernel taints the kernel. This condition may be visible in system logs, kernel ...
5
votes
3answers
754 views

Disadvantages of linux kernel module?

I am trying to understand the disadvantages of using Linux kernel modules. I understand the benefits of using them: the ability to dynamically insert code into a running system without having to ...
5
votes
1answer
1k views

Custom kernel: fails to load firmware when module built-in

I'd like to have all my modules built-in, but this fails with iwlagn: iwlagn 0000:03:00.0: request for firmware file 'iwlwifi-6000-4.ucode' failed. iwlagn 0000:03:00.0: no suitable firmware found! ...
5
votes
2answers
771 views

What package could “linux-headers-3.7.5-1-ARCH” mean?

I'm debugging a closed-source software installer that seems to have some pre-conceived notions about my distribution. The installation aborts after not finding apt-get. The command it attempts to run ...
5
votes
2answers
309 views

Unclaim a device

So I am using Ubuntu and trying to use some hardware which I had some problems with before. The problem before was that the company who made my hardware sold their internal parts to another company ...
5
votes
1answer
303 views

Loading speedstep_centrino kernel module

Because of a noisy fan in my laptop, I need to change CPU frequency and for this task I need to load the appropriate kernel module. The CPU in my laptop Acer TravelMate 4002WLMi is: $ cat ...
4
votes
1answer
750 views

Booting without initrd

Is it possible to boot linux without a initrd.img ? I am planning to add default drivers as a part-of-kernel itself and avoid initrd completely. What are the modules that should be made ...
4
votes
1answer
2k views

Find out which modules are asociated with a usb device?

Please recommend way to figure out which driver is being used for a USB device. Sort of a usb equivalent of lcpci -k.
4
votes
2answers
523 views

Kernel Modules: .o vs .ko

It seems that files containing kernel modules are called .o, at least that's what I figure when looking at a tutorial like this one. However, on my debian squeeze box, these files seem to be called ...
4
votes
2answers
1k views

Can I detect if my custom made kernel was built with module support?

I have been provided with a vendor supplied minimal linux installation. From an answer to a previous question I discovered that it is possible to build a kernel with or without module support. I have ...
4
votes
1answer
10k views

How to solve “building the main Guest Additions module Failed”

I tried to install the VirtualBox Guest Additions module in a VM guest running CentOS but I get this error message when everything else was okay: building the main Guest Additions module Failed ...
4
votes
1answer
334 views

When should I keep debugging symbols in kernel modules?

When installing kernel modules, I have the option to strip out debugging symbols using INSTALL_MOD_STRIP=1. This saves significant disk space. Does it also save memory? Why should one keep the ...
4
votes
1answer
1k views

How to know whether the Linux driver for the real-time network device was built into the kernel?

From here: http://www.xenomai.org/index.php/RTnet:Installation_%26_Testing#Debugging_RTnet The Linux driver for the real-time network device was built into the kernel and blocks the hardware. ...
4
votes
2answers
317 views

How to debug an inserted kernel module?

I would like to debug a loaded kernel module I don't have the source code to; I suspect it's a virus. Is there a way to feed it into GDB for analysis?
4
votes
1answer
372 views

Automatically apply module patch and compile kernel when updated?

I've recently applied a one-line patch to drivers/bluetooth/btusb.c in order to enable compatibility with my Bluetooth device. However, whenever I get a kernel upgrade, the patch will be lost until ...
4
votes
1answer
415 views

What are EXT4 Security Labels?

During Gentoo installation of Gnome keyring, I am told to switch on EXT4 Security Labels, which is described in the kernel documentation by: Security labels support alternative access control ...
4
votes
1answer
318 views

FedUp, unable to upgrade to Fedora 20

I am upgrading my Fedora OS to the latest version 20 as the current one is nearing end of life. Fedora introduces a new upgrade method called FedUp that allows user to perform an upgrade over the ...
4
votes
2answers
97 views

How can I prevent iptables from counting bytes and packets on empty chains?

Background I occasionally have firewall rules that I need to use for maintenance windows, but don't want active (and therefore consuming CPU cycles or slowing the network interface) the rest of the ...
4
votes
1answer
2k views

ALSA/ASoC: How to correctly load devices/drivers?

I am using Buildroot to build an embedded Linux (2.6.39.2) system for the NXP LPC3250 microcontroller. Right now, I'm trying to get ALSA/ASoC up and running, but I'm having some issues with getting ...
4
votes
3answers
138 views

Why do I need to comment out the floppy in /etc/fstab in new-ish Debian versions?

I'm using a box with Debian that has gone through many updates (at least lenny, squeeze, wheezy). After a long time, I wanted to mount a floppy again which didn't work as it used to. I found a ...
3
votes
2answers
2k views

Adding a new System call to Linux 3.2.x with a loadable kernel module [closed]

I want to add a particular new system call in the linux kernel 3.2.x but as a loadable kernel module (as I don't want to recompile the kernel again and again) I read through many posts on internet ...
3
votes
2answers
103 views

Using multiple layer of kernel modules for interfacing a hardware device?

I am trying to get a conceptual understanding of the purposes the kernel modules can have. The motivation for this question was a realization that interface to an actual hardware goes through multiple ...
3
votes
2answers
1k views

Why does modinfo say “could not find module”, yet lsmod claims the module is loaded?

According to the man page of lsmod the command shows “what kernel modules are currently loaded”. I wrote a script that uses modinfo to show what kernel object (.ko) files are actually in use: ...
3
votes
2answers
1k views

How do I build the iptables kernel module for a loaded kernel?

I've built a kernel with loadable module support for various reasons, one of them the possibility to compile modules and load them without rebooting. This is supposed to be useful when I need a module ...
3
votes
1answer
537 views

Do I have to list modules in both `/etc/mkinitcpio.conf` and `/etc/rc.conf`?

I've added few modules into mkinitcpio.conf. Are they automatically loaded at kernel boot or with udev if I don't specify them in modules list in rc.conf?
3
votes
2answers
973 views

Problem at boot-time: “Loading user-defined modules [FAIL]”

After I updated my Kernel to version 3.0, i always get this line when my Arch-Linux system is booting up: Loading User-specified Modules [BUSY] [FAIL] I have no idea what could cause this to ...
3
votes
1answer
92 views

How to build a custom kernel with localmodconfig that support hardware of multiple machines?

When configuring a server to run a single task, like an appliance, there might rise the need to build a custom kernel. For example to save disk space. Ubuntu Core 13.10 amd64 root filesystem is a ...
3
votes
4answers
2k views

How to determine which module taints the kernel?

My kernel keeps panicking when connected to a certain wireless network. I'd like to send a bug report but my kernel is apparently tainted. From /var/log/messages: Apr 17 21:28:22 Eiger kernel: ...
3
votes
1answer
284 views

Changes to input_get_keycode function in linux kernel (input/input.c)

I'm working on building a kernel module for an input device, and I noticed that in the module source, there's a couple calls to input_get_keycode(data->input_dev, scancode, &keycode); When I ...
3
votes
2answers
106 views

How can I load a module at runtime?

I just compiled the qcserial module which is a driver module for a Gobi USB modem. Now I have a couple of questions. Now I have two files: drivers/usb/serial/qcserial.ko and ...
3
votes
2answers
3k views

Ubuntu make fails with No such file or directory /lib/modules/3.4.0/build

I am trying to build the CP210x driver for the 3.x.x kernel on ChrUbuntu. Build instructions: Ubuntu: make ( your cp210x driver ) cp cp210x.ko ...
3
votes
3answers
5k views

How to remove kernel module if it's still in use?

[rootSERVER ~]# rmmod -f cifs ERROR: Removing 'cifs': Resource temporarily unavailable [rootSERVER ~]# modprobe -r cifs FATAL: Module cifs is in use. [root@SERVER ~]# lsb_release -a LSB Version: ...
3
votes
1answer
377 views

Xenomai and Ubuntu

I have installed xenomai 2.4.8 in Ubuntu 11.04 with this command: apt-get install libxenomai-dev Now I want test a simple vxWorks program, but when I compile my program, I receive this message: ...
3
votes
1answer
879 views

Do I need pata_atiixp or ata_generic kernel modules on a SATA only system?

I don't have any IDE drives and my only SATA hard drive is running in AHCI mode, but my initrd image loads the pata_atiixp module. Is it safe to disable this module? And what about the ata_generic ...
3
votes
1answer
87 views

Finding a char device in /sys using a Bash script?

I have one of these and I am trying to write a Bash script for finding the device path in /sys. My approach goes something like this: start in /sys/modules/usbled since this is the name of the ...
3
votes
2answers
324 views

kernel module function call

I write a kernel module which has initialize and end function. I want one more function and want to call it from the user space process at any time i want. Is it applicable ? If so, how ? I am ...