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

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U-Boot Bootup error

I'm running a Debian Linux on a Cubietruck, running off a SD card. When I power on, I get the following error: Booting kernel from Legacy Image at 46000000 ... ...
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Is the PTTY inside the Kernel or Userspace?

I read, that drivers are a way to expand the Kernels abilities to communicate with hardware devices, since there are so many and will be even more the Kernel has to be expandable. In order to ...
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Keyboard merely plugged in greatly increases kernel boot time

Specs are here. I am using a K65 RGB. I am using the ckb-git package from the AUR to provide basic input functionality. With Keyboard and with driver: Startup finished in 3.100s (firmware) + ...
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New laptop - hub over-current condition

I bought a new laptop Lenovo B50-70 and I abe installed Linux Mint. In the syslog is long output og messages: .... hub 1-1:1.0: over-current condition on port 3 hub 2-0:1.0: over-current ...
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How did the Linux Kernel project track bugs in the Early Days?

We all know that Linus Torvalds created Git because of issues with Bitkeeper. What is not known (at least to me) is, how were issues/tickets/bugs tracked up until then? I tried but didn't get anything ...
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How to create an initrd image on OpenSuSE linux?

/usr/src/linux-3.2.1 # make install scripts/kconfig/conf --silentoldconfig Kconfig sh /usr/src/linux-3.2.1/arch/x86/boot/install.sh 3.2.1-12-desktop arch/x86/boot/bzImage \ System.map ...
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139 views

OOM Killer value always one less than set

I am trying to set the oom_adj value for the out of memory killer, and each time I do (regardless of the process) I get back exactly one less than I set (at least for positive integers. I haven't ...
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Which bus drivers to include when compiling freeBSD kernel?

I'm trying to compile a FreeBSD kernel and make it as light as possible. I'm struggling with the configurations on the bus, especially the SCSI Controllers part. there are many modules e.g: ahc, ahd , ...
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What is a Kernel Routine ?

In another answer I met a short overview of the sections of the man pages: commands for $-User system call, that means evoking a function from the Kernel library call, that means evoking a function ...
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2k views

Kernel booting stops right after “Uncompressing Linux…”

I'm trying to bring up an ARM-based board. I've got U-Boot working but can't seem to get the kernel to load. Most of the time it only goes as far as: Starting kernel ... Uncompressing Linux... A ...
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can't find “buildkernel” target in FreeBSD source files

I'm trying to compile a FreeBSD 9.3 Kernel. in the docs it states that the commands make buildkernel and make installkernel must be run, However I can't find these two targets anywhere in the make ...
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How to get the Adaptec 1200A to work under Linux at UDMA/100 (instead of 66)

A while ago, I got myself a used Adaptec 1200A controller card to keep my onboard slots free for easier connect/disconnect of drives and now I am wondering why this card will only operate at UDMA 66. ...
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How do you empty the buffers and cache on a Linux system?

Prior to doing some benchmarking work how would one free up the memory (RAM) that the Linux Kernel is consuming for its buffers and cache?
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Scaling issues of i7 3520M with intel_pstate module on Kernel 3.10.0

Few days ago I updated my openSUSE 12.3 system from Kernel 3.9.8-1.gf3348a8-desktop to 3.10.0-1.g3dcd746-desktop and since then, turbo mode of my i7 3520M is enabled by default and it does not ...
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ulimit & rlimit in Linux, are they the same thing?

I see people use the terms ulimit & rlimit interchangeably, can I say they are referring to the same thing?
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Where to download Linux Kernel source code of a specific version?

Is there a resource to download a specific kernel version source? For example, I want to get 2.6.36.2 sources to compare with this package and see what changes were introduced?
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Capturing key input from events device and mapping it (toggle TouchPad key is unmapped)

I have a Lenovo IdeaPad Yoga 13 with Ubuntu 13.10 Installed. The device has a "Toggle TouchPad" button on the keyboard (F5). The keyboard's F* buttons are reversed (so to get F5, I need to press Fn + ...
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2answers
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busybox initramfs loop mount

I'm trying to loop mount my root filesystem (a loop file) within a busybox initramfs. I try to run the command: mount /rootfs.raw /root ... which works on my Ubuntu laptop, however, I simply get ...
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Find out which kernel source files were used when kernel was compiled

I am compiling the Linux kernel for my specific hardware and I only select the drivers/options which I really need. This is in contrast to a typical distribution kernel, where they compile almost ...
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/dev/input/event0 is missing in embedded linux

I'm working on a project and we are trying to make a touch-screen work using Qt with Tslib. We already made some previous prototypes and we managed to make them fully functional. But when creating a ...
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1answer
103 views

Compiling kernel but doesn't build kernel modules

I am trying to compile a linux-sunxi kernel for my Banana pi. Using this link: http://sunxi.org/Linux_Kernel#Compilation Unfortunately I am getting the following message at the bottom when I am ...
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git: show which files have changed between kernel 3.18.6 and 3.18.7

I have checked out linux kernel git repository git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git I know how to use git log, git show and similar commands to see ...
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Benefiting of sched_autogroup_enabled on the desktop

I am running a 2.6.37 kernel with sched_autogroup_enabled set to 1. I am not certain that I am seeing the benefits of this patch since: I am launching my applications from the desktop; applications ...
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Pfsense source code to build firewall

Pfsense is an open source Firewall based on openBSD kernel. Where can I find the code and how to modify it to build my firewall?
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Ping IP works, nslookup fails. New Kernel

I am compiling my own 3.14 kernel. I fear I may have left out some important networking feature to get DNS working. I can't resolve domain names. I can ping my DNS server. I can resolve using that ...
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MMU-less kernel?

I would like to try compile mmu-less kernel. From what I found in configuration there is no option for such a thing. Is it possible to be done?
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473 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 ...
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Compiling a loadable kernel module(Debian/Ubuntu)

This question is a follow up of this one. I am trying to compile the ELF loader as an individual LKM and use it as a standalone application(replacing the original module within the base kernel sounds ...
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bnx2: Can't load firmware file “bnx2/bnx2-mips-09-6.2.1b.fw”

I just compile the kernel 3.10.19 from kernel.org Support for bnx2 is enable. On my server when I try to start the eth0 interface I got the following error : bnx2: Can't load firmware file ...
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Calling ioctl on same file descriptor from two different processes [migrated]

If I call ioctl (this is a custom kernel driver to read/write Altera registers), and another process calls ioctl on the same file descriptor while the first ioctl is still executing, does the first ...
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1answer
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Get kernel source: apt-get install vs apt-get source

I'm looking forward to download a Linux Kernel to get to know how to modify it and how to compile it. I am using Debian distribution and I'm interested in the Debian-modified Linux Kernel rather than ...
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How can I boot into Ubuntu with a linux kernel with an earlier version?

Part of the output of ls -ld /usr/src/linux-headers* on ubuntu 12.04 is: drwxr-xr-x 24 root root 4096 Jun 4 2013 /usr/src/linux-headers-3.2.0-45 drwxr-xr-x 7 root root 4096 Jun 4 2013 ...
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Can I limit the size of the linux file cache?

I am running 64-bit Xubuntu 14.04, linux version 3.8.0-25 with 8GB of RAM. I have a script (in MATLAB, for what it's worth) that loads a large number of data files (~23k) one at a time, for a total ...
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How do I completely remove a wireless interface (and re-add it)?

I'm trying to use a new usb wireless interface (atheros ar9271) and my onboard wireless (intel 6200) is interfering with it. The goal is for me to be able to turn the rf kill switch on (enabling ...
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Issue with network up/down in kernel [migrated]

I am trying to write a Linux kernel module that with the correct command, will bring down the the network interface (lets say wlan0) change its IP address to the one specified, then bring the ...
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2answers
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vmlinuz and initrd not found after building the kernel?

After configuring and building the kernel using make, why don't I have vmlinuz-<version>-default.img and initrd-<version>.img, but only got a huge vmlinux binary (~150MB)?
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How can I know which IRQ is responsible of high CPU usage

I've moved a server from one mainboard to another due a disk controller failure. Since then I've noticed that constantly a 25% of one of the cores goes always to IRQ however I haven't managed myself ...
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Why would the kernel drop packets?

I interrupted tcpdump with Ctrl+C and got this total summary: 579204 packets captured 579346 packets received by filter 142 packets dropped by kernel What are the "packets dropped by kernel"? Why ...
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Centos 7 boot up with custom kernel problem

I have installed centos 7 on virtualbox machine which has kernel-3.10.0-123.20.1.el7.x86_64. I am trying to build Linux kernel from kernel sources. I downloaded the kernel source files from: ...
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What does the 'i8042.nomux=1' kernel option do during booting of Ubuntu?

I have a laptop with a multi guesture touchpad. My touchpad never works in any Linux distro such as Ubuntu, Fedora, openSUSE, Linux Mint, Knoppix, Puppy, Slitaz and lots more. I have tried lots of ...
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SCTP support for Linux kernel 3.3.4-5.fc17.x86_64

I'm using Fedora 17 64-bit version, with Linux kernel version 3.3.4-5.fc17.x86_64. I installed lksctp using yum. sudo yum install lksctp-tools.x86_64 When I try to run sctp_status -H 127.0.0.1 ...
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Get static driver from kernel zImage

I have one kernel zImage inside that there is one static modules for touch panel So is it possible to get touch panel module from zImage because I have no kernel source Please guide me
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Generate major page faults

Is it possible to generate major page faults in the linux kernel at will? Can a program be written such that it is guaranteed to cause a major page fault on it's execution.
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Silent booting Linux from u-boot

For security reasons I have to boot Linux from u-boot with all output hidden (silently) until a password is entered. I've configured uBoot to do this correctly using the CONFIG_AUTOBOOT_KEYED macro ...
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setting (system-wide) CPU affinities for running processes on a Linux platform

I am conducting a kind of research in that I schedule multiple parallel applications (e.g., OpenMP/pthreaded applications) and execute the applications on specific (partitioned) cores on Linux-based ...
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Linux Networking Bootup script takes too long

I am working with a fork of a raspberry pi SoC. One of the modification is the use of AP6210 WiFi/Bluetooth chip. I am running Debian. During boot up, the following 3 startup scripts need to run in ...
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How to see kernel time variables without using adjtimex?

The man page for adjtimex says Anyone may print out the time variables, but only the superuser may change them. How do I see the value shown by adjtimex -p as the tick variable without using ...
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Recognizing GPT partition table created with different logical sector size

I have a 3TB drive which I have partitioned using GPT: $ sudo sgdisk -p /dev/sdg Disk /dev/sdg: 5860533168 sectors, 2.7 TiB Logical sector size: 512 bytes Disk identifier (GUID): ...
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How does the Linux kernel initialize console graphics?

Observation: I switch on a Linux box Boot loader displays its output on screen Boot starts with first output messages Screen goes blank, and never comes back on. Note: this is about the console, ...
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Kernel ATA Exception after resume from suspend to RAM

After resuming from suspend to RAM, my Arch Linux system freezes and becomes permanently unresponsive. However, I managed to pull the following kernel log: kernel: sas: Enter sas_scsi_recover_host ...