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

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15
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3answers
367 views

How to force Linux kernel to “freeze” (or nearly freeze) for a few hundred milliseconds

We are running a real-time process on a non real-time kernel (CentOS 6), and this is probably not going to change. We have a streaming video application that requires about 500 MB/s of PCIe traffic ...
0
votes
0answers
67 views

Best approach to adding a kernel driver

I have a task to complete. An LED must be controlled immediately after the kernel loads and into the launch of a Debian system. It also must be controlled in user land. I already have basic LED ...
2
votes
1answer
96 views

What does kernel-wedge do?

After looking at the package description and using kernel-wedge help, I'm not really sure what it does. Does it take a .deb kernel package and split it into smaller packages? Does it compile a ...
0
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0answers
54 views

How to recompile official OpenSUSE kernel & initrd?

But it is not okay. I want all of the suse patches applied, I want an official initrd to be generated, and I want to make rpms from all of them. So, I want to recompile the kernel just as the SuSE ...
2
votes
0answers
147 views

Explanation of the building process of the kernel on Ubuntu/Debian systems

I'm getting into Linux kernel programming and I have successfully built my own kernel several times now. However, I have done it using step by step guides found from the internet and I don't really ...
0
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0answers
91 views

Fedora 20 won't startup after shutdown during kernel update

I had a few bugs in my System(System Settings not opening and Firefox not starting) and I thought a kernel update(via yum) could do it some good. During that update, I suddenly got logged out as if ...
1
vote
1answer
211 views

Full UEFI System, Grub 2 self-compiled + Clover 2, Debian kFreeBSD installation?

I've a computer with full installation UEFI system, with 2 bootloaders (GRUB & Clover on ESP) clover is the primary bootloader that allows me to load OSX and grub2. I want to make a new install of ...
0
votes
2answers
86 views

Compilation error when building a custom kernel

I'm trying to build a custom kernel from a git repository on my Ubuntu virtual machine. I run the make command as follows : sudo apt-get install vim libncurses5-dev gcc make git exuberant-ctags mkdir ...
1
vote
1answer
78 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 ...
1
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0answers
96 views

Linux Oracle - Random crash CPU Stuck

I have several Linux oracle VMs running under hyper-V. Kernel version is 2.6.32-358.el6.x86_64. Sometimes, the VM stuck, we still can ping it, but we cannot ssh, or through the hyper-v console this ...
1
vote
0answers
62 views

How build wireless-compat-old in-kernel?

I'm running linux 2.6.24 with custom patches from Freescale, on an embedded board. I want to use a usb wlan modem that uses the Realtek rtl8191su chipset. Realtek provides a driver out of tree, ...
0
votes
1answer
267 views

ZFS support for linux kernel versions 3.16

Attempting to boot Funtoo with a debian-sources-3.16.2-3 kernel, in a system where the root file-system lives in a zpool, drops off to the rescue shell after failing to import the pool properly. Does ...
1
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0answers
38 views

extract Embedded initramfs

I have a kernel in which one initramfs is embedded. I want to extract it. I got the output x86 boot sector when I do file bzImage I have System.map file for this kernel image. Is there any way to ...
2
votes
1answer
54 views

How to find the source of a currently running kernel on my machine?

I have a Linux 3.14.0 kernel(CentOS 6.2) running on my machine, but the source isn't in /usr/src/. Is there any way to find out the source from which it was compiled? The source is most definitely ...
2
votes
0answers
110 views

Why will plymouth not update?

I admit I don't update my kernel very often. I used to everytime a stable release of sys-kernel/gentoo-sources came out so I'm very adept at doing it. This last weekend I attempted to update from ...
0
votes
1answer
191 views

Mount JFFS2 FS in openwrt

I'm trying to mount 1[MB] of flash as JFFS2 FS in openwrt environment, using 128[MB] NAND flash (4 bit ECC). I'm using the following sequence - flash_eraseall -j dev/mtd6 mount -t jffs2 -o noatime ...
1
vote
1answer
590 views

Kali Linux - “package has no installation candidate” (also thinkpad-acpi)

I was trying to install the thinkpad-acpi package unsuccesfully, since it had not found the directories needed at all. (no such file or directory response after running the cat ...
0
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0answers
389 views

yum install kernel-devel: “Nothing to do” [SOLVED]

I need the kernel-devel package to compile a program(How to check if USB WiFi-Adapter is not working or router is out of range?), but when I try to install it via yum, this is the only output: yum ...
0
votes
1answer
112 views

How to recover firmware on a embedded device with corrupted u-boot and kernel image? [closed]

My embedded device is not working after updating firmware. Thus I tried to update firmware using u-boot. I could successfully get u-boot console via serial connection, but updating firmware failed due ...
0
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0answers
25 views

third party linux auditing software

Linux has a audit system built-in in its kernel and a user space process called auditd reading the system calls intercepted by the kernel. Are there alternate solutions to the Linux Audit system ? I ...
1
vote
2answers
108 views

Linux 3.x init ramdisk embedded in bzImage?

Is the initial ramdisk embedded into the bzImage? How to load an rootfs.cpio as a ramdisk and switch the root?
1
vote
0answers
184 views

Linux 0.0.1 Kernel - Starting Kernel Programming

To start kernel programming, instead of reading the books, the online references suggested to download the linux 0.0.1 source and find bugs. I have downloaded it and I am going through the code with ...
3
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1answer
812 views

Real time processes scheduling in Linux

I have been learning some scheduling concepts. Currently my understanding so far is as below. There are real time processes and non real time processes. Non real time processes can have nice values ...
0
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0answers
24 views

Patching and Compiling my Kernel

So I have an issue with my USB 2.0 ports and I believe I have found a solution for it, which is in the below link. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1210858/comments/32 I have ...
0
votes
1answer
313 views

Debian stable: Only GNOME classic with custom 3.16

I compiled a custom 3.16.2 today, which works flawlessly except that GNOME only starts in classic mode. Maybe this is due to changes in the drm i915 driver, but how would I debug this? System is a ...
2
votes
1answer
87 views

strace works for some builtin commands

I'm trying to understand some kernel level concepts in Linux. I was checking on the difference between shell builtin commands and the other executable commands. This wonderful answer clearly tells ...
1
vote
1answer
33 views

rebuilding kernel without using apt-get

I am setting up my Macbook Air 6.2 with Debian Jessie. since I do not have any wireless, I need to set it up manually, but all documentation I find how to do it are using apt-get apt-get install ...
0
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0answers
137 views

USB Keyboard Hotplug Module not Working

The following module could be compiled and loaded without any error: #include <linux/module.h> #include <linux/kernel.h> #include <linux/usb.h> #include <linux/usb/input.h> ...
2
votes
0answers
37 views

Why does each process folder under /proc contain the same information?

Under /proc/<PID>/net pseudo-file system each process seems to have files with the same content. For example I use cat /proc/<PID>/net/ip_tables_names to list iptables tables under the ...
0
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0answers
40 views

how to limit dma address to specific range in linux kernel?

I want to limit the dma address the device can access to 0x0100_0000~0x03ff_ffff. But I don't know how to set the dma_mask and coherent_dma_mask. It's easy to set the "dma mask" for a range start ...
0
votes
0answers
79 views

Noob Kernel Image Question

I'm playing about with CM-FX6 , an iMX6 based SOC. The chip comes with the following: http://www.compulab.co.il/workspace/mediawiki/index.php5/CM-FX6:_Linux:_Kernel **images** uImage-cm-fx6 - ready ...
2
votes
0answers
39 views

Why is there no rootfs file system present on my system?

The linux kernel documentation claims: Rootfs is a special instance of ramfs (or tmpfs, if that's enabled), which is always present in 2.6 systems. You can't unmount rootfs … On all linux ...
1
vote
1answer
53 views

Booting into a kernel image

I have a recently-compiled Linux kernel image (vmlinuz file) and I want to boot into it. I am aware that this won't give me a familiar Linux system, but I am hoping to be able to at least run some ...
2
votes
1answer
1k views

How does bash execute an ELF file?

When I'm on my Linux Box I use bash as a shell. Now I wondered how bash handles the execution of an ELF file, that is when I type ./program and program is an ELF file. I grepped the bash-4.3.tar.gz, ...
0
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0answers
29 views

LVM2 Mirror Support Missing from Kernel after System Migration

I had a system that was running on a small netbook that had LVM2 set up to group two external USB hard drives into a volume group, and to use that volume group to create a mirrored logical volume. ...
3
votes
1answer
44 views

Real-time executive approach, can be run in desktop Linux?

With the real-time executive approach, a small real-time kernel coexists with the Linux kernel. This real-time core uses a simple real-time executive that runs the non-real-time Linux kernel as its ...
1
vote
1answer
306 views

How do I compile the linux kernel version 3.16.1 to run in Slackware 14.1?

Could someone teach me or give me some tutorial? How do I compile the linux kernel version 3.16.1 to run in Slackware 14.1.
6
votes
1answer
143 views

Linux kernel 3.10.0-123.4.2 processes [flush] aren't present

I am using CentOS 7 with "3.10.0-123.4.2.el7.x86_64" version, but I don't know why the kernel threads named flush aren't present in this kernel version. I tried to look in the kernel change log, but ...
0
votes
0answers
25 views

Generate what a GRUB2 kernel line would look like

In GRUB 0.97 we were able to see what the kernel line/options would look like by just viewing /boot/grub/grub.conf. Now the only way I know how to check the next boot kernel options/kernel version ...
1
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0answers
50 views

Kexec immediately after Kickstart install (where is cmdline?)

I used to be able to kexec into a new kernel immediately after a kickstart (anaconda) install via pxe. I was able to do this by figuring out the current kernel version, and grabbing cmdline options ...
2
votes
1answer
47 views

Installing a new OpenBSD kernel “safely”: why does `make install` go through these extra hoops?

After building a new OpenBSD kernel, the install target of the kernel Makefile does the following: rm -f /obsd ln /bsd /obsd cp bsd /nbsd mv /nbsd /bsd I understand that the first two lines remove ...
1
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0answers
60 views

“disagrees about version” message

I get a message "disagrees about version" on boot time, after compiling kernel and modules with KGDB. Why should this happen ? Is there any problem with KGDB ? This is the relevant log at boot: ...
0
votes
0answers
200 views

Resume from Suspend/Hibernate issues

I have a peculiar problem while trying to resume from both suspend and hibernate. I believe the problem to be within the kernel itself since I have tried different distros (Ubuntu, Suse, Mageia) on ...
0
votes
0answers
90 views

How to boot on a ramdisk?

I'm working on a linux embedded for a custom board with a ARM9 processor. My kernel version is : 2.6.33 I'm trying to boot on a ramdisk, kernel correctly mount the file system but failed to execute ...
1
vote
0answers
80 views

What does __ prefix before some kernel api's convey?

Why do some function calls in kernel specially have this prefix __ example: __init initialization(void) is __init a macro? What does this convey? Are these a special class of function calls inside ...
1
vote
3answers
467 views

How to install/make the kernel section 9 manpages which document its functions and data structures?

The kernel sources contain functions and data structures which are documented, for instance in panic.c: /** * panic - halt the system * @fmt: The text string to print * * Display a message, ...
9
votes
1answer
2k views

How pipes work in Linux

I've been reading up about how pipes are implemented in the Linux kernel and wanted to validate my understanding. If I'm incorrect, the answer with the correct explanation will be selected. Linux ...
1
vote
1answer
103 views

/proc/config.gz is of 0 bytes

I have an Android TV stck I compiled Linux for IT from https://github.com/Galland/rk3x_kernel_3.0.36 But when I booted that Image I found /proc/config.gz is of 0 bytes can some please explain how ...
3
votes
1answer
105 views

eCryptfs key in kernel image or initramfs

I have an embedded Linux system with unencrypted kernel image and initramfs in NAND flash. My RootFS is in SD card. I want to encrypted some files on SD Card as my SD card is easily accessible ...
0
votes
0answers
28 views

Module load map

How can I obtain a module load map? I've tried with the -m flag in insmod but it seems that since 2.6 there is no support for it. Thanks