What is the relationship between framebuffer, VT, and tty?
I'm now studying what is the mechanism behind Ctrl+Alt+F1~F7.I found some infomation talk about framebuffer, VT, and tty. I know framebuffer is an anstraction to graphic card manipulation and tty(and...
View ArticleHow to enable etnaviv drivers without using Yocto build?
I have custom board with kernel 4.14 and vivante drivers 6.2.4p4.0 (Official Freescale's ones). I want to test my Qt application using the mesa drivers instead of the Freescale's. I've already...
View ArticleHow to run the script at login in LINUX only for root user [closed]
I have tried this script in location /etc/profile.d/#!/bin/bash mkdir -p /tmp/palash cd /home/palash echo end the script This script is executing for every user. I want to run this script under root...
View ArticleTask activation status in Linux Kernel
I have only one user program and i launch it on a particular core. I would want the kernel to know immediately whenever this user program is activated and starts running. Is there any way for the...
View ArticleAbout Linux PID0 Idle task per cpu core
I am working on CPU-IDLE in Linux. I have the question who spawns idle tasks per CPU core i.e. if there are 4 arm CPU cores, who spawns the per CPU idle task? Where the code for the same is located for...
View ArticleYocto generated linux modules do not contain all the drivers selected in config
I am trying to configure yocto linux kernel to enable some drivers using this SDK DOCUMENTATION FOR T1042D4RDB-64B. Until now, What I did is these steps;1) bitbake virtual/kernel -c cleansstate2)...
View ArticleExecute this script shell [duplicate]
This question already has an answer here:Expansion of variable inside single quotes in a command in Bash 7 answersI tryin to execute a script.sh but i get this...
View Articledifficulty to start/find resources for these questions about Kernal
So I'm new to Kernel, C, and linux. I saw this online coding challenge, where it asks the following:Question: What trace command could you use to do each of the following? Explain each part of the...
View ArticlePagefault due to read access to exsisting page
Read in professional Linux kernel architecture by wolfgangMauerer"In the event of a read access to an existing page (Case 1), the fault must be a permission fault detected by the hardware. Execution...
View ArticleWhy ksm in linux scans virtual memory instead of physical page
The question is about mm/ksm.c in Linux Kernel source code. In Linux Kernel, KSM scans for virtual memory per progress instead of physical pages directly. But I think scan for physical page can work...
View Articlemmstartup -a is not working in centos 7.3
[root@localhost ~]# /usr/lpp/mmfs/bin/mmstartup -N localhostTue Nov 19 17:22:35 IST 2019: mmstartup: Starting GPFS ...localhost: mmremote: startSubsys: The...
View ArticleIs it possible to reclaim Private_Clean pages?
I have a process that has to read a bunch of stuff from a mmap()ed file and then does memory intensive processing of some of this data (discarding the mmaped data as it gets processed). In my case, the...
View ArticleProbelm with using Threads in Linux kernel Module
I am developing Linux kernel module which is communicating with my user-space C application. In this module, I am creating a thread. this is a part of my module where I am facing the problem :static...
View ArticleHow is the address of the text section of a PIE executable determined in Linux?
First I tried to reverse engineer it a bit:printf ' #include <stdio.h> int main() { puts("hello world"); } '> main.c gcc -std=c99 -pie -fpie -ggdb3 -o pie main.c echo 2 | sudo tee...
View ArticleCPU1 failed to come online
Could someone explain why we get the message below in kernel in SMP environment?CPU1 failed to come onlineSource kernel_msm-4.9/kernel/arch/arm/kernel/smp.c:if (!cpu_online(cpu)) { pr_crit("CPU%u:...
View ArticlePatch Kernel-Module Makefile
I have a Linux-Kernel for NXP i.MX6. There are some capture kernel-modules in /driver/media/platform/mxc/captureOne of the files call mxc_v4l2_capture.c. I had to change this file for using it with my...
View ArticleNDP cache not updated on global scope addresses
On Kernel 4.19.0-6-amd64 I'm having an issue using the following IPv6 topology:I have 2 gateways, one "master", one "slave" and some hosts. Hosts default gateway point only to master ip (scope global),...
View Articleuser space address dereference in kernel
I have allocated user space address using compat_alloc_user_space api, but sometimes de-referencing this pointer or address would cause page fault in 4.X kernel, but de-referencing in 3.x kernel works...
View Articlestuck at percpu_ref_switch_to_atomic_sync waiting for !ref->confirm_switch
I am debugging this issue in the Linux kernel where I see one thread stuck waiting for per-cpu reference counter to switch to atomic mode. This is how the function looks like:void...
View ArticleTabs disappeared on terminal in Linux
I am facing a little problem in linux terminal. All the vi editors which I've opened on the terminal used to come as tab on the lower portion of the terminal because of which I was easily able to...
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