Everything about UNIX kernels: development, configuration, compilation, design, etc.

learn more… | top users | synonyms

1
vote
1answer
497 views

Enabling ethernet over USB support in Linux kernel

How to enable Ethernet over USB support in Linux kernel? Which driver (like CONFIG_USB_USBNET) is related to this support? Is EEM (Ethernet Emulation) regarding this support or not?
0
votes
3answers
6k views

Empty kernel directory but kernel-headers are installed

Host - Windows 7 Guest - CentOS I am trying to install kernel-headers using yum since during the installation of vmware-tools I get a message asking for the path to the kernel header files for the 3....
5
votes
3answers
12k views

Set default kernel in GRUB

How can I pick which kernel GRUB2 should load by default? I recently installed a the linux realtime kernel and now it loads by default. I'd like to load the regular one by default. So far I only ...
0
votes
0answers
35 views

How do I enable higher C-states on Xeon 1505m with Linux?

I am running a Lenovo ThinkPad P70 with a Xeon E3-1505M v5. Installed the 201604 Arch, most everything is running well, except power states. The kernel I'm using is 4.5.1-ARCH, but I've also tried 4.6 ...
0
votes
0answers
16 views

How do I compute the angle of the 2D 3 points ? [[ In kernel space]

I 'm looking at the touch driver 's Kennel. Sometimes a touch is bouncing County singah appear. Collected by recruiting three points 'm trying to calculate the angle between . But there is no such ...
0
votes
1answer
110 views

How to use the proper video driver on Scientific Linux 6 for Display Port screens?

I am working with (one of) my workstation(s) working under Scientific Linux 6, so, basically a quite old version of Red Hat Enterprise Linux. I would need to use 2 screens, but only have 2 DisplayPort ...
2
votes
0answers
49 views

How to support 64-bit times on a 32-bit Linux platform

I need to support 64-bit times on a 32-bit ARM embedded Linux system based on kernel version 4.1. I use clock_gettime() and clock_settime() to get/set the time, but they are limited to 32-bit seconds ...
0
votes
0answers
38 views

Kernel problem after upgrading to 4.5.1

I updated my kernel from 3.19 to 4.5.1 (which is the latest ubuntu-based upgrade), and when I rebooted, I saw an alert: Alert! /dev/disk/by-uuid/xxxxxxxxxxxxxxxxxxx does not exist! where x's are ...
0
votes
0answers
17 views

ALG IPSEC and RSTP

I have linux 3.18. my Linux is installet on a router. in this router I activate a NAT from the wan side. Does this Linux support ALG of IPSEC and RSTP ?
0
votes
0answers
21 views

Installing Wireless Adapter (GWU625 v1.1) On Modern Fedora OS

I am trying to install the driver to GWU625 v1.1. You can download it here for what it is worth. It is recommended for Fedora v10 but I want a to run an OS which is supported by the people who ...
0
votes
1answer
22 views

Are IPv6 link-local addresses assigned by the kernel or by a userspace program

When IPv6 is enabled for an interface, it will get a link-local address assigned automatically based on the MAC of the network interface. But who assigns this address? Is it done in the kernel, or by ...
0
votes
1answer
28 views

What is kernel Space and User space. [duplicate]

what is Kernel space ? i want to understand it and same with User space and what is the diff between them
0
votes
1answer
641 views

Linux distro with PREEMPT_RT patch

I want to know if there is any Linux distribution with PREEMPT_RT kernel patch? If not, is there any good tutorial on how to patch and compile a kernel with RT patch and how can I create kind of a ...
1
vote
1answer
39 views

How to block drivers built-into Kernel, i.e. drivers who are not a module

I configured and compiled Linux kernel with nouveau driver built-into kernel, i.e. with <*> as opposed to <M> when doing make menuconfig inside Linux kernel source directory. Now, I ...
3
votes
1answer
66 views

How to simulate GPU hardware failure?

I'm doing some research that has to do with GPGPU resilience with NVIDIA graphics cards and I've been looking for a way to, as accurately as possible, simulate hardware failure. I know about ...
2
votes
0answers
129 views

How to compile custom kernel for Raspberry Pi

I'm trying to run the Ubuntu 14 Raspberry Pi ARM image in QEMU, and for that I need the kernel that matches the version used in the image. If I mount the image and run file vmlinuz I see: vmlinuz: ...
0
votes
3answers
50 views

Filesystem kernel API

Assuming that all filesystems are specific, how tools like ls, touch, cat, etc interacting with them? I suppose that 'ls' doesn't know specifics about btrfs for example, but it reads directory entries ...
0
votes
2answers
61 views

How is redirection implemented?

Is redirection a concept of the shell, not of the OS kernel? How is redirection implemented in terms of system calls? Is redirection implemented similarly to pipe?
0
votes
2answers
41 views

Cleaning swap space while running

I have a theoretical question, What would happen if I clean up all the swap space while running, Would the operating system crash because of page faults that would happen in the kernel?
2
votes
2answers
165 views

Change Wireless adapter driver in Linux

I am using openSUSE Tumbleweed. I've bought a new PCI-E Wireless card, that supports 5G WiFi (Intel 5100 AGN). It doesn't show up in lspci and even if I take old adapter out it still cannot see my ...
0
votes
0answers
42 views

m2c : Command not found

I want to experiment on DCTCP protocol. For that I am trying to compile linux kernel version 3.2.18 and include a dctcp patch for that. I am following the directions given here. While I am compiling ...
0
votes
1answer
30 views

Uprobes Status on the present linux kernel

I know uprobes was introduced on kernel 3.5 has it survived or is it dropped, is it still available on kernel 4.x
0
votes
0answers
31 views

minimum time between two consecutive UDP packets

I am interested in developing a C application which sends UDP packets with minimum delay between two consecutive packets. Is it possible to "book" the UDP stack with the NIC hardware from user space ...
2
votes
0answers
66 views

Linux usb-drive write cache

Is there any way to change the way the Linux kernel handles external storage and the external storage cache? Every time I copy something to it, the copy process seen from userspace seems really fast. ...
0
votes
0answers
10 views

it terms of terminology is there an accepted difference between a kernel agent and a kernel module or a kernel driver?

In terms of terminology is there an accepted difference between the concept of a kernel agent, kernel module, or a kernel driver?
8
votes
1answer
2k views

Why does the linux kernel use linux-libre code to get rid of binary blobs?

I ask this question because I'm curious as to whether there is some sort of performance advantage offered from the binary blobs that are in the Linux kernel. Since many of these blobs have been ...
1
vote
0answers
61 views

Userspace Network Stack

I am writing a (very simple) userland IP network stack. For this purpose, I need to go "around" the OS network stack and obtain the raw Ethernet frames. The tap interface sounds like a way to go, but ...
22
votes
3answers
34k views

How to disable USB autosuspend on kernel 3.7.10 or above?

I've updated my HTPC from kernel 3.7.10 to 3.10.7 and it seems CONFIG_USB_SUSPEND is now gone from the kernel options and included in PM. The main problem I'm facing is that I have an external HDD ...
0
votes
0answers
145 views

dracut-initqueue: Could not boot, /dev/disk/by-uuid does not exist

I've just installed second linux kernel on my machine and after the boot, I'm getting following error: dracut-initqueue: Could not boot [Warning] /dev/disk/by-uuid/943eb4bb-be3f-4252-83e9-...
1
vote
0answers
21 views

How to verify NX usage in Linux kernel?

I'd like to verify that the current system is using NX bit protection somehow. I know that this can be done by checking the initial lines in the dmesg output. But that's a rolling buffer, so I'm not ...
1
vote
0answers
27 views

How to uninstall linux kernel?

I was building linux kernel from git master for ubuntu all day, I was not able to build packages, so I just ran sudo make module_install install. How to remove it? Makefile doesn't provide make ...
1
vote
2answers
1k views

How to manually compile Fedora 20 kernel

I am trying to recreate an environment for debugging purposes. I require Fedora 20 specific kernel version (in this case its 3.17.7-200.fc20.x86_64). I have manually compiled vanilla kernel (3.17.7) ...
1
vote
2answers
1k views

Linux Kernel - Wacom Tablet (CTL-490DW-S) - Lockout

I'm a bit of a beginner with Linux and after trying to fix this over the last few days I've finally given up and need your help. I'm trying to use my new Wacom (CTL-490DW-S (Intuos DRAW)) drawing ...
4
votes
2answers
3k views

When will Debian switch to Linux 4.x? ( and support the live kernel patching ? )

Wikipedia says that current Debian 8.2 Jessie is based on kernel 3.16.0, so I was wondering when a native version based on kernel 4.x would be released and if the live kernel patching will be there as ...
2
votes
1answer
142 views

How does a bootloader actually hand off to a kernel?

Assume I have a bootloader with a kernel and initrd line. For all intents and purposes, I now have 2 or 3 stages of "kernel" going on: firmware grub (or other bootloader) actual linux kernel The ...
1
vote
1answer
53 views

Wacom Tablet (integrated; X201T) disconnects sporadically

I have an X201 tablet with stylus and finger multitouch running Ubuntu 14.04.4 with the 4.2.0 kernel. For no apparent reason, it seems to have an affinity for not recognizing finger (henceforth ...
1
vote
0answers
71 views

How to know when I could reactivate HWP (Hardware PStates)

I have a x1 carbon 4gen, and my computer hangs during boot on "HWP enabled" message. For now the solution is to disable HWP (Hardware PStates) with the option intel_pstate=no_hwp on boot. There is a ...
5
votes
2answers
13k views

Partition table not recognized by Linux kernel

I experience relatively often that the partition table of a USB stick or SD card is suddenly no longer recognized by the kernel while (g)parted and fdisk still see it, as do other systems. I can even ...
0
votes
0answers
26 views

Kernel make install error for RTAI 3.8 on CentOS 6.5

Before posting I have read almost every similar post I could find on this and other websites but I haven't found an useful answer. I have to install a custom software that needs RTAI 3.8 on top of ...
0
votes
0answers
70 views

Kconfig (bool/def_bool/tristate)

In a Kconfig file, what are the differences between : bool def_bool tristate Thank you.
2
votes
2answers
116 views

How to get the absolute position (x, y coordinates) of a finger on a touchpad?

Main question: How to get the absolute finger position on the touchpad? I would like to get the absolute position (x, y coordinates) of a finger on a touchpad? I believe it is possible to extract it ...
2
votes
2answers
746 views

Wireless constantly reconnecting on Ideapad running Arch

I just bought a new laptop, a Lenovo IdeaPad U330 touch, and after some struggle (with the Secure Boot stupidity) I have managed to install Arch Linux. I have configured my system, installed all the ...
0
votes
1answer
30 views

is there a description for kernel messages?

I use dmesg to output kernel messages, but since I'm new to linux I have no idea what this informations mean. Is there a good tutorial or description so I can understand the messages. for example: ...
0
votes
0answers
29 views

Mouse button stops working intermittently

I have noticed that I'm not the only one with mouse button problems. This problem seems to affect multiple users on many different Linux versions regardless of Desktop versions (at least in Unity &...
0
votes
1answer
87 views

What step am I missing to get my 2.6 ARM kernel running in QEMU?

I am trying to cross-compile and boot a Linux 2.6 kernel for ARM using QEMU. I have basically followed the same instructions that are included in seemingly every single tutorial on the topic. ...
1
vote
0answers
33 views

How to trace the life cycle of kernel threads by following creation and switching?

How to trace the life cycle of kernel threads by following creation and switching ? kernel_thread() and schedule() are the 2 functions I know that but have no idea how to implement it..
0
votes
2answers
418 views

Why can't I find kernel headers on CentOS 7 when trying to install VirtualBox Guest Additions?

I have a minimal CentOS 7 installation as a VirtualBox 5.0.16 r105871 guest on a Windows 8.1 host. uname -r reports "3.10.0-327.10.1.el7.x86_64". When I try to run VBoxLinuxAdditions.run I get an ...
0
votes
0answers
11 views
0
votes
0answers
11 views

Raspbian Kernel Oops at fs/dcache.c

We have a Raspberry Pi 2 running Raspbian 8 Jessie. We are running a simple Python 3 based Flask server to read from GPIO pins and toggle a relay (Externally powered). This system is polled every ...
0
votes
0answers
18 views

Ubuntu upgrades blocked due to insufficient disk space for linux-image [duplicate]

I am running Ubuntu Server 14.04 LTS on a desktop at my home that I was intending to turn into a server, but I never really did much on it. I then decided to turn it into a send-only SMPT server, but ...