Tagged Questions

The kernel of operating systems popularly known as Linux, or sometimes GNU/Linux.

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2
votes
1answer
38 views

What could be done to make Embedded Linux boot faster?

My team is developing a software for a Embedded Linux solution. The problem we are facing is that it takes too much time for the system to be ready to start running our desired apps (that is, too much ...
1
vote
0answers
17 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 ...
1
vote
1answer
38 views

Does it take time for process to utilize CPU?

I have a single-core x86 machine where I execute the burnP6(from cpuburn package) for 1 second and then kill the program: while true; do /usr/bin/burnP6 & sleep 1; pkill burnP6; sleep 1; done ...
-1
votes
0answers
10 views

linux kernel module for sha512 [migrated]

I'm programming a linux kernel that computes sha1 of input text with 20 bytes output. But I can't find any function for sha512. please help me
0
votes
0answers
16 views

Linux Booting from NAND instead the uSD

I have some trouble with booting up my zImage. I'm using CORE9G25. So, usually I boot up using the uSD. And after uncompressing the linux and etc it's working. But, after I moved the uSD to the other ...
1
vote
0answers
19 views

process duplication [migrated]

how to create a process at kernel level? As the functions do_fork and copy_process are static we cannot use them, so is there any way we could use their functionalities or do I have to implement ...
0
votes
0answers
31 views

custom built kernel module problems

I have been struggling to find a solution for loading module ath9k into the kernel and I have met a dead end. The kernel is 3.17.1 taken from kernel.org and I am compiling it in Ubuntu Trusty (14.04) ...
2
votes
1answer
48 views

Will kdbus replace D-Bus?

According to this LWN article kdbus is supposed to replace D-Bus. Can this be confirmed somehow? I wonder if after all this will be an easy task as I would imagine that both have a distinct API? To ...
0
votes
1answer
44 views

grub will not boot new kernel

For some time back I installed Linux mint 17 on my desktop machine, which is a dell studio 540. During the installation process, I did not have any internet connection, because my wireless card needed ...
2
votes
3answers
56 views

cannot reconfigure virtualbox-dkms

I have installed vitualbox on Debian Jessie according to instructions on debian wiki. By running: apt-get install linux-headers-$(uname -r|sed 's,[^-]*-[^-]*-,,') virtualbox During installation ...
2
votes
0answers
31 views

How to determine the wordsize in Linux kernel programming? [closed]

In userspace code, the macro __WORDSIZE is used, included in <bits/wordsize.h>. However, when I do Linux kernel programming, the __WORDSIZE seems not available. If <bits/wordsize.h> is ...
4
votes
1answer
25 views
+50

Error compiling custom kernel with a new usb serial driver

I have tried compile a driver for my kernel 3.13.0-40-generic. I have also tried compile a custom kernel with this driver but both have failed. The name of the driver is vizzini for Linux ...
1
vote
0answers
14 views

ifup wlan0 causes kernel Oops

on my laptop, when I do ifup wlan0, sometimes I get following call trace in dmesg. Other times, the log looks perfectly normal, and there are no kernel Oops messages. In both cases (with errors and ...
1
vote
0answers
25 views

GFP mask of 0x200da on a 64-bit system?

Recently, an OOM showed a GFP mask of 0x200da on a 64-bit system. How is that possible? 0xa would suggest we are talking about Movable Highmem, see: ...
2
votes
2answers
169 views

Are Linux drivers part of the kernel or the rootfs

I have been working on a board with an embedded ARM processor. To get it to boot I have to add a bootloader, a linux kernel and a disk image containing the root file system. This disk image is ...
1
vote
1answer
39 views

running vanilla kernel with LTS distro

what can potentially go wrong when running a custom vanilla kernel (e.g 3.16.3) with an LTS distro (e.g Linux mint 17)
5
votes
1answer
41 views

What is ENOANO (No Anode) intended to be used for?

This question is merely for idle curiosity, but I suspect others will be curious as well. Searching through errno.h (of Linux 2.6) I found ENOANO "No Anode". There is no sign of a "No cathode" error. ...
2
votes
0answers
26 views

“can't write to batman adv kernel file” while using “batctl p mac-address”

I installed batman-adv and batctl on Ubuntu 14.04.1. When I issue the comand: batctl p 00:16:bf:01:68:46 I get this error: Error - can't write to batman adv kernel file ...
1
vote
2answers
53 views

Why does Linux store cpu temperatures on so many files?

I have a laptop(thinkpad) with 2 cpus. Currently I can read the cpu temperatures from the files below with cat(1): cat /sys/class/thermal/thermal_zone0/temp cat /sys/class/thermal/thermal_zone1/temp ...
3
votes
0answers
24 views

Why does a device show up as hidraw instead of hiddev?

I read the kernel documentation for hidraw and hiddev, and I understand the differences, but I am wondering how the kernel decides whether or not a device should show up as /dev/hidraw* or ...
2
votes
0answers
7 views

Why doesn't enabling the rtc interrupt show in the /proc/interrupts? [migrated]

I've written a simple app to enable rtc interrupts. #include <stdio.h> #include <fcntl.h> #include <linux/rtc.h> #include <sys/ioctl.h> int main() { int fd = ...
1
vote
0answers
16 views

Weird X11 behaviour after resume from suspend

I experience the following problem with xfig, but I don't believe that it is a xfig problem: In xfig, I draw a text and then I can move it around with the mouse (after going into move-mode). As I ...
3
votes
1answer
116 views

Boot delay due to non-existent SATA disk

My ASUS M4A87TD EVO board has two on-board disk controllers, one of them is a JMicron JMB361 with one old IDE disk connected. When I boot Arch Linux, it shows in the system journal like this: Nov 02 ...
5
votes
1answer
112 views

Calls to sync/fsync slow down after 30 minutes uptime

After 30 minutes of uptime using Ubuntu 14.04 with a hybrid SSD I see many processes blocking IO using iotop. This is during disk writes, for example if I open and close an empty file in gedit it can ...
2
votes
0answers
31 views

Where is located syscall_table in kernel x86_64? [migrated]

I'm trying to add new System Call to Linux Kernel(x86_64). Based on this article which explained how to add System Call to Kernel(x86). The article says I need to define my System Call name in a file ...
1
vote
0answers
32 views

open() sys call [closed]

Process A wants to open a file fd1 = open("/var/file1", O_RDONLY); In the process of opening file1 which table is referred first system wide file table or file descriptor table or in-core inode ...
3
votes
3answers
108 views

System calls supported in running Kernel

Is there a way to get the number of or list of system calls supported by currently running Linux Kernel? So I want to find a way to 'read' the syscall table of a running kernel.
2
votes
1answer
126 views

Delaying kernel upgrades on Arch Linux

On Arch Linux, whenever a kernel upgrade is applied (via pacman -Su), problems occur. For example, iptables can no longer be used: # iptables -L iptables v1.4.21: can't initialize iptables table ...
1
vote
2answers
85 views

Why should you not edit the .config kernel configuration file?

# Automatically generated file; DO NOT EDIT Is at the header of the kernel configuration file: /usr/src/linux/.config My question is why, why should you not edit this file? If I know exactly what I ...
2
votes
1answer
71 views

Tool to give only the built linux source code

Linux is large complex piece of software. A running kernel in the system would not be using all the code. I'm looking for a tool which can give me the source code needed for the .config I used to ...
0
votes
0answers
6 views

OpenSuse 11.1 Keyboard Issuses

Im having some repeat issues with my keyboard being unresponsive. Im using opensuse 11.1 with a 2.26.27* kernal and it seems to be getting worst. When the keyboard dies (although the mouse works) , ...
1
vote
1answer
86 views

Fedora 20 ACPI issues on black screen before log on

I installed Fedora 20 64-bit with the standard Gnome3 desktop environment and while booting a black screen is displayed with 4 messages in the following form: Failed to find handle for ACPI object ...
0
votes
0answers
20 views

rtnetlink No such file or directory error For Red algorithm

I tried the following command on my Ubuntu 14.04 Virtual Machine: tc qdisc add dev eth0 parent 1:1 handle 10: red limit 400000 min 30000 max 90000 avpkt 1000 burst 55 ecn adaptive ...
0
votes
0answers
33 views

System not responding and ttyS0 (ttyS0) main process (1627) killed by INT signal

The system is not responding(Unable to do SSH or Telnet, even scheduled cron job is not running) if it runs for more than 5 days. The scenario is "the ssh session is opened and console is opened from ...
1
vote
1answer
42 views

How to test new kernel releases ?

I am using ubuntu 14.04 with linux kernel 3.13.0-37-generic . I know that the latest stable release of the kernel is 3.17.01 and want to test it. Can I test it on my system without blowing away my ...
2
votes
1answer
71 views

Which Debian kernel should I install?

I've started installing Debian testing on amd64 and I've come to a screen asking me to install a kernel. It gives me a choice between linux-image-3.16-2-amd64, linux-image-amd64, and none. What is ...
0
votes
3answers
50 views

Linux Distro name API to get name of linux distro in a driver code?

I am writing a common code in a driver to get the distros name and host name. host name i am taking from struct utsname{nodename[]}, but how do I get the distro name?
0
votes
1answer
70 views

Role of the Intel P state driver

I searched high and low for what “Intel P state” is and what it does. I found out that it has to do with performance and power consumption. I learned that if you build it in the kernel, it'll becomes ...
0
votes
0answers
40 views

How to display printk messages filtered by level as they come?

I wrote a hello word module that performs a printk when it is loaded in level ALERT and another printk when it is released with level INFO: #include <linux/module.h> #include ...
1
vote
0answers
43 views

How to create the framebuffer file node?

I'm working with a limited embedded device - Linux environment - that uses a custom DirectFB implementation to draw a user interface in its video output. I would like to exchange this method by a raw ...
0
votes
0answers
37 views

Kernel version name is repeated twice

I'm compiling my own kernel on Ubuntu. I use make deb-pkg -j5 to compile and package the kernel. In the kernel Makefile, I have added "-mykernel" to the extraversion part of the version string. ...
8
votes
1answer
384 views

Why do user space apps need kernel headers?

I'm building busy-box and iptables for an embedded device and one of the dependencies for them are the kernel headers. I have searched the whole file system for *.ko files and found none. So i ...
-1
votes
1answer
49 views

Add codes to vmlinuz

When I use the vi editor to add some codes to /vmlinuz I see it in a bad format. It seems a binary file. I am going to improve security and add extra steps for checking password. How can I edit ...
2
votes
1answer
96 views

Display power management in console

When in console (i.e. not in Gnome or KDE) the display will automatically power down in case of inactivity. It seems to me to be set to something around 30 minutes. This power management is completely ...
0
votes
0answers
21 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 ...
0
votes
0answers
864 views

Nvidia driver not working on latest kernel (3.17) and Ubuntu 14.04

I'm pretty new to kernel hacking. However, I have built my own kernel before (3.16) and it works. Now I tried upgrading to the latest kernel (3.17-rc7). I configure the kernel using the config file ...
1
vote
1answer
38 views

Binding to not existing interface

I've just noticed the very weird situation I don't have a good explanation for. The machine (debian) has one interface with one IP address assigned: # ifconfig vmbr0 |grep inet inet ...
3
votes
1answer
65 views

Easy way initrd to chain loading another kernel with kexec

I have here a machine which won't boot 64-bit kernels (it has efi32 with a little bit of... uncommon firmware). Currently, my only way to boot my 64-bit linux system is: Booting a 32-bit distro ...
0
votes
0answers
18 views

DEBUG_RODATA option in the linux kernel

I am wondering what exactely the use of DEBUG_RODATA is in the linux kernel. The help says: CONFIG_DEBUG_RODATA: Mark the kernel read-only data as write-protected in the pagetables, in order to ...
3
votes
1answer
34 views

kernel: pass option to driver, when not compiled as module

I had the driver for my sound card compiled as module, i.e.: CONFIG_SND_HDA_INTEL=m and I did pass following options to the module (via /etc/modprobe.d/alsa-base.conf): options snd-hda-intel ...