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

learn more… | top users | synonyms

3
votes
2answers
176 views

How is the kernel loaded?

I am trying to understand the Linux boot process, and after reading quite some amount of documentation there is one point that I still can't seem to understand. So the basicis is BIOS -> Grub MBR -> ...
14
votes
2answers
1k views

The UEFI & SecureBoot impact, how severe?

I'm planning to buy a new laptop in the coming days, and I'm quite impressed with new, cool Ultrabooks. As a long-time GNU/Linux user, I'll of course install a distro of my choice on it. Chances are ...
2
votes
1answer
329 views

How to run Different congestion control algorithms in FEDORA 17 ..?

Earlier versions of Fedora has different loadable kernel modules which includes diffrent congestion control algorithms etc at (/lib/modules/"kernel-name"/kernel/ipv4).These are present in the form of ...
24
votes
1answer
581 views

What would be the best way to work around this glibc problem?

I administer a Gentoo Hardened box that uses file capabilities to eliminate most of the need for setuid-root binaries (e.g. /bin/ping has CAP_NET_RAW, etc). Infact, the only binary I have left is ...
1
vote
1answer
470 views

No make target “uImage” with Buildroot 2013.05

After enabling Linux Kernel option and setting the Kernel binary format to uImage, I always get the following error: make[1]: * No rule to make target `uImage'. Stop. My buildroot configuration is ...
1
vote
1answer
77 views

Linux Operating system recovery after abnormal termination

How does the operating system (Linux) while rebooting checks whether abnormal termination happened during last shutdown and then does the file system consistent checks etc if required ?
0
votes
0answers
20 views

Preparing an initrd for qemu [duplicate]

I have compiled a bzImage but when I try to run it in qemu I get a kernel panic because I don't have an initrd file. So I create one by following the steps in this question but I cannot get it to ...
1
vote
2answers
1k views

Why TCP TIME-WAIT State is present at both ends after a connection termination?

I am reading how the TCP states work and especially the connection termination part. All of the books or online material I read, shows that for the termination procedure these states are followed ...
4
votes
2answers
2k views

Linux kernel is not finding the initrd correctly

I had compiled a linux kernel and I wanted to debug it in QEMU. I created a file to boot from by doing the commands $ qemu-img create -f raw disk.img 200M $ mkfs.ext2 -F disk.img # mkdir /mnt/rootfs ...
2
votes
5answers
201 views

How to know what to enable in the kernel?

I'm a gentoo user. When compiling the kernel there are a lot of options which one may enable depending on one's hardware. My question is how to know what to enable/disable, I'm aware of the hardware ...
0
votes
2answers
2k views

Installing qemu-img on ubuntu 11.04

I am developing a linux kernel and I am trying to to debug it in QEMU. I want to be able to run it in QEMU but it stops because I do not have a virtual hard drive to boot it(using the -hda command). I ...
0
votes
2answers
238 views

Writing a Linux file system for NFS

I want to write my own custom file system in Linux. Can I share it over standard NFS without making any changes to the local NFS server? If so what VFS APIs are required to be implemented by my file ...
1
vote
1answer
66 views

Multi kernel usage in Linux PC(UBUNTU)

I have 2.6.32-21-generic , 2.6.32-38-generic and 3.0.0-20-generic. My current kernel is:- $ uname -r 2.6.32-38-generic I want to use different kernel that is 2.6.32-21-generic. How can I do that?
0
votes
2answers
353 views

Compiling the Linux kernel in Eclipse

I have a Mac running Snow Leopard and I know that I cannot compile the Linux kernel. I have used a Linux VM (virtualbox) to compile the kernel but I was wondering if I could compile it on Eclipse ...
1
vote
1answer
982 views

Invoking memory compaction on linux 2.6.35 kernels and beyond

This LWN article about memory compaction indicates that memory compaction can be invoked in the linux kernel by Writing a node number to /proc/sys/vm/compact_node, causing compaction to happen on ...
1
vote
1answer
1k views

How can I disable IPv6 in custom built embedded setup

I have an embedded system built using buildroot. I have had a number of network issues, one of which is that my machine cannot see its gateway despite it being on the same subnet. I have tried using ...
1
vote
1answer
212 views

core dump help— linux

I'm trying to understand the core dump generation. Is the core dump generated separately for a user space application process crash and the kernel level crash? Is the ulimit -c for both kinds? Can you ...
0
votes
2answers
528 views

swap partition and its laws

I remember for choice of swap partition, we should use (swap > 2xRAM) at least.Of course it deprecated , because max of computer's ram is very high. kernel support it. My question: i remember each ...
0
votes
0answers
23 views

Best way of updating Openssl on Linux machine [duplicate]

I have a confusion to choose the best way for upgrading the OpenSSL on my Linux machine. 1*Through the yum Update.* # yum update I know this will update the entire packages. But If I want to ...
2
votes
2answers
235 views

How to edit grub2 to use kdump?

I was following http://fedoraproject.org/wiki/How_to_use_kdump_to_debug_kernel_crashes and in step 2 I need to add the line to grub.cfg, but grub.cfg is a shell I do not know how to edit it, most ...
4
votes
1answer
2k views

Is it possible to run any distro from RAM from within an .iso saved on an NTFS file system?

Running entirely from RAM been done on various distros such as Slax, DamnSmallLinux, and newer Ubuntu versions, and since I have 8GB it seems reasonable that I could run many distros entirely from RAM ...
2
votes
0answers
216 views

Update jiffies value after waking up from suspend

The global variable jiffies holds the number of ticks that have occurred since the system booted. On boot, the kernel initializes the variable to zero, and it is incremented by one during each timer ...
5
votes
3answers
1k views

Disadvantages of linux kernel module?

I am trying to understand the disadvantages of using Linux kernel modules. I understand the benefits of using them: the ability to dynamically insert code into a running system without having to ...
1
vote
0answers
308 views

Is there any ARM platform for which high resolution timers are available in mainline (unpatched) kernels?

I currently have some projects using a TS-7400 board, which has a Cirrus Logic EP9302 ARM9 processor. Some of my applications require a 1ms periodic timer, so after lots of struggling I found these ...
33
votes
7answers
5k views

Why does mount require root privileges?

Why does Linux require that a user be root/using sudo/specifically authorized per mount in order to mount something? It seems like the decision as to whether to allow a user to mount something should ...
1
vote
1answer
462 views

Change of real time priority made no visible effect

we were trying to get the best result with software PWM on raspberry pi with Raspbian. We made a python script which starts PWM on a GPIO pin, and observed the results with the oscilloscope. It ...
1
vote
0answers
171 views

How customize initrd via linuxrc

I have the need to use the same disk and so the same bootloader on devices with different motherboard. Each motherboard has it's own way of mapping devices so sometime the bootdisk is mapped ad hda ...
4
votes
1answer
128 views

User Mode Linux compile fails

I am trying to compile User Mode Linux on a 64 bit machine with defconfig and getting the following error. arch/x86/um/user-offsets.c:1: sorry, unimplemented: code model "large" not supported yet ...
1
vote
0answers
238 views

How to setup an audio/sound output monitor/listener? [closed]

I am working with an Arduino and am trying to get it to respond to sound when it is played on my computer. I'm communicating with it over a serial port. I need to know if there are any audio/sound ...
0
votes
1answer
44 views

USB_HID is not working

How do I get a usb keyboard to work? I have already selected and compiled the USB HID transport layer and I don't know what else to do.
2
votes
0answers
55 views

kgdb not returning control to gdb

I've compiled a kernel with kgdb support and I'm trying to debug it. I have two machines running, a debug machine (running the kgdb kernel) and the machine I'm using to debug it. They are connected ...
3
votes
0answers
233 views

My SMDK2416 (for s3c2416) kernel works on 64MRAM but crashed on 128M

I'm currently working on embedded arm linux with smdk2416(s3c2416) The kernel is working on the 64MRAM. Recently, I need to increase the RAM from 64M to 128MB with 64MB on bank0 and 64MB on bank1. ...
0
votes
1answer
2k views

make: *** No targets. Stop while building linux kernel module [closed]

I am just trying to learn how to driver modules for Linux Kernel. I followed Linux Device drivers 3rd edition book and started my work. I created a sample program and makefile. Please find my makefile ...
2
votes
1answer
485 views

USB3 Hard Drive Not Recognised by Linux

My external USB 3 hard drive is behaving very strangely: If I plug it into a USB 2 port, it works fine If I plug it into a USB 3 port, it doesn't work at all. It's not even mentioned in ...
3
votes
3answers
366 views

AES-NI on Dell Vostro 3360

I don't have AES-NI available on my Dell Vostro 3360 laptop. Why? Does this machine not support it? My /proc/cpuinfo: processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 58 ...
-1
votes
2answers
2k views

Where can I find a good tutorial for installing bcache? [closed]

Question is updated. Now bcache is part of the standard OS compilation. So it should be easy to install that now. I'll just order some SSD and some big HDD. Where can I found it? I found on the net ...
1
vote
1answer
230 views

Linux kernel 3.2 syscalls

Just trying to get the assembler instructions for <__execve> of the code below because i want to build the shell spawn opcode list: #include <stdio.h> int main() { char *happy[2]; ...
1
vote
1answer
229 views

How to compile linux kernel and debug with gcc and BOCHS?

I have download bochs 2.6 sourcecode and installed with gdb-stub configuration. I would like to debug linux-kernel 1.0 or 2.0 or 3.0 which sourcecode downloaded from http://www.kernel.org/ with gcc ...
1
vote
3answers
654 views

Linux Kernel: uid and gid vs /etc/passwd

How does the Linux kernel deal with UIDs and GIDs? When I want to add a user to a system, does the kernel require some type of "registration" for this user (syscall?)? Does the kernel even care about ...
4
votes
1answer
2k views

Kernel and QEMU : Unable to mount root fs error

I am trying to run a distro in the virtual disk image with a custom kernel,so that I can experiment and debug the kernel. I followed this to make a disk image and then install Debian to it. Now I ...
12
votes
5answers
833 views

Linux on a 286?

I don't own a 286 nor do I intend to run Linux on one. However since the 286 has protected mode, why is it frequently stated that Linux requires a 386 CPU or higher? From ...
2
votes
0answers
3k views

mounting udev on /dev failed: No such device

I am trying to compile Linux kernel 3.2.36 with its source code on the x86_64 architecture. I followed the following set of commands under my Linux source distribution directory: make defconfig ...
2
votes
1answer
865 views

Debugging Linux Kernel with QEMU

I was trying to study the debugging of kernel using QEMU. I tried initially and failed due to the fact that there was no virtual file system. The answers to this post suggests that there should be a ...
7
votes
3answers
4k views

Why is the theoretical RAM limit for RHEL 6 128 TB and how is this determined?

I'm studying for RHCSA and am confused by a statement I came across in some training material: There is no practical maximum RAM, as theoretically, you could run 128 TB of RAM on RHEL 6. But ...
1
vote
0answers
420 views

Where does the Linux kernel reside in memory ?

From some book I have, I have in my notes that the Linux kernel resides at 0xc00000000 on 32-bit systems, and is mapped into user space for performance reasons. Is this accurate ? How can I verify ...
1
vote
0answers
93 views

Android strace error: “strace: 2: Syntax error: ”&“ unexpected”

I was using built-in strace given in /system/xbin/ directory in the emulator and it was giving me wrong set of system calls such as msgget() and msgrecv() which are not supported by Android even. I ...
1
vote
1answer
168 views

Linux, Debugger program development

We are trying to implement the debugger program which will takes either PID or Program name as input and Invoke the gdb by using PID. Below is two small programs are written, Not able to figure out ...
0
votes
2answers
858 views

After removing linux Grub error

I have a dual boot Windows & Linux system. I removed the Linux partition, but after that I am not able to go in to Windows XP. It is not booting. It gives me a GRUB error.
1
vote
0answers
118 views

Creating a Virtual filesystem to boot linux

I am trying to boot the linux kernel (bzImage) in QEMU but have had issues. After asking on U&L I found out that my problem was that I was booting the kernel without a filesystem to boot from. So ...
2
votes
2answers
931 views

Automatic kernel configuration tool

Is there any developed automatic linux kernel configuration tool? I have found a method of make localmodconfig, but it is certainly very limited. I have searched the web but unfortunately have not ...