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

learn more… | top users | synonyms

10
votes
3answers
1k views

What defines the maximum size for a command single argument?

I was under the impression that the maximum length of a single argument was not the problem here so much as the total size of the overall argument array plus the size of the environment, which is ...
4
votes
1answer
406 views

What is the “kernel build”, and where do I get it?

I am trying to compile OpenOnload from Solarflare for my nic on a server that I'm building. It is saying something about not having a kernel build. root@server:/usr/src/openonload-201310-u2# ...
1
vote
1answer
65 views

Linux Web Kiosk [duplicate]

Hi I'm having a idea of develop a light weight Linux kernel which will boot and open a web browser in full screen and request data from pre define URL. Can any one give me some guides on this please. ...
1
vote
1answer
39 views

Different Kernel in /boot and the kernel built tree [closed]

I discovered after a binary comparision that my old kernel in /boot was different from the kernel that I had built and kept backed up in the kernel source tree. A while ago I also had a few ...
2
votes
1answer
372 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 ...
8
votes
2answers
916 views

How exactly does printk work internally?

I know printf needs help from the OS to do its job. I also know printf does not work in the Linux source code as there is no library. And so we have printk for debugging. How does printk work ...
-1
votes
1answer
39 views

Linking option while installing Linux [closed]

I have installed Linux kernel from source. The way I do this is that I first do make menuconfig and then make inside the root directory of the source code. As a result of this I get a an ...
3
votes
2answers
359 views

How does a bootloader and kernel interact after the kernel is loaded in memory?

I'm a little bit confused about the role of bootloader and its interaction with kernel, especially when talking wrt ARM Llnux. Once the Kernel is loaded into RAM, is there any job left for the ...
0
votes
1answer
336 views

Starting Bootlog daemon: bootlogd

Whenever I run linux on many ARM based systems, I see a message like this: Starting Bootlog daemon: bootlogd. As can be seen from the log messages below, it takes some finite time, close to 0.5 ...
1
vote
0answers
123 views

Looking for a list of modules that are used during boot sequence

I'd like to use deferred init calls. This function allows to load modules in userland, that should actually be loaded during the boot sequence. Just for testing I'd like to modularize as many entries ...
2
votes
1answer
68 views

How does the kernel know which file descriptor to write data to after fork() in a concurrent server?

Basic concurrent client/server architecture: There's a main loop listening for requests on a port (for example 3000), after accepting the connection the server spawns a child process that ends up ...
6
votes
2answers
3k views

BSD Kernel Vs. Linux kernel? [closed]

I wanted to know in technical terms; what is the difference between BSD Kernel and Linux Kernel. In Linux, we can download the source kernel then patch it and make and make modules it. Even we have ...
12
votes
3answers
2k views

Why there are many BSD systems but only one Linux kernel?

Why there are many BSD systems but only one Linux kernel? I wonder why BSD was forked many times, but no such thing with Linux.
23
votes
4answers
1k views

What are the responsibilities of each Pseudo-Terminal (PTY) component (software, master side, slave side)?

I am trying to figure out how a tty works1 (the work-flow and responsibilities of each elements). I have read several interesting articles about it, but there are still some blurry areas. This is ...
3
votes
2answers
211 views

Using multiple layer of kernel modules for interfacing a hardware device?

I am trying to get a conceptual understanding of the purposes the kernel modules can have. The motivation for this question was a realization that interface to an actual hardware goes through multiple ...
4
votes
1answer
99 views

How to relate a kernel config setting to the source files?

Here is an example that will explain better: I have a selected the audio driver from the picture and i would like to browse through its source. How do i get to the path of the source files from ...
3
votes
1answer
1k views

How to get ondemand governor on fedora

In Ubuntu 13.10 on my (Dual Core i5 Lenovo G570) laptop, I recently discovered the wonders of indicator-cpufreq, so I can extend my battery life dramatically by setting it to 'ondemand' or 'powersave' ...
1
vote
0answers
244 views

How do I fix this boot-up error (attempt to read or write outside of partition)? [closed]

I just installed a version of ubuntu linux that I got from here, http://www.bauer-power.net/2013/06/bauer-puntu-1304-is-alive-download-it.html using vmware workstation. I have installed it before ...
1
vote
2answers
1k views

“select” vs “depends” in kernel Kconfig

What are the differences in dependencies between select and depends on in the kernels Kconfig files? config FB_CIRRUS tristate "Cirrus Logic support" depends on FB && (ZORRO || PCI) select ...
0
votes
1answer
118 views

How can I replace the default kernel with an earlier kernel?

I am working on petalinux, Linux for xilinx FPGAs. The source code is here This Linux is having 3.x kernel, and I have been asked to change the kernel to some earlier release version. What are the ...
1
vote
1answer
3k views

How to get back from “testing” to “stable” - Kernel downgrade

currently I am having lot's of fun with apt-get - and the bad thing is, it was my own fault. I had enabled the testing packages in /etc/apt/sources.list to install a certain package. And I told my ...
1
vote
2answers
1k views

running kernel on QEMU

I face this message: Failed to execute /initKernel panic - not syncing: no init found. Try passing init=option to kernel. I am using this command line: qemu-system-x86_64 -hda disk.img -kernel ...
4
votes
3answers
1k views

What distribution still supports the 2.6.x kernel?

I'm trying to use a Khepera III robot. The documentation says I need a Linux OS with kernel 2.6.x. An Ubuntu 8 image was provided at the website. When I created a virtual machine with that image, I ...
1
vote
1answer
99 views

Why my cpu spend so much time on system? [closed]

top - 08:58:42 up 20 days, 8:23, 1 user, load average: 67.17, 58.94, 62.75 Tasks: 630 total, 40 running, 524 sleeping, 0 stopped, 66 zombie Cpu(s): 57.3%us, 41.6%sy, 0.0%ni, 0.0%id, 0.0%wa, ...
3
votes
3answers
2k views

Self-built kernel: failed to mount /dev: No such device

I am trying to install a Linux kernel (3.8.1) from source in a Fedora distribution. The kernel is a vanilla one. I follow the kernel's build instructions closely that is: make menuconfig make sudo ...
1
vote
2answers
92 views

CentOS 6 with Linux-Libre kernel?

I understand that CentOS ships with nonfree blobs in it's kernel. It seems that a "nonfree blob" free kernel exists, a.k.a. Linux-Libre. Is it possible to somehow get CentOS to use Linux-Libre ...
3
votes
3answers
160 views

Is it mandatory to have a file system and MMU in Linux? [closed]

Suppose I do not need a filesystem and I have only applications where data reloading may not be required - so MMU may be redundant. Can I remove these two items from Linux, and boot the OS ...
8
votes
3answers
867 views

Is there a file for each socket?

"Everything is a file" in the UNIX World. Above sentence is famous. When I run echo "hello programmer" >> /dev/tty1 , I can watch the given string on TeleType 1 , .... What and where is file ...
1
vote
0answers
210 views

D-Link usb dongle detection problem [ Debian Wheezy ]

according to this topic,I was upgrade kernel from 3.2 to 3.12 (using .deb backport),But at installation process I get some error message like this : # dpkg -Ri kernel3.12 Selecting previously ...
3
votes
1answer
1k 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 ...
1
vote
1answer
155 views

Debian/Ubuntu:How to compile a Linux kernel on one machine and use on other machines (same architecture)

Debian/Ubuntu: How to compile a Linux kernel on one machine and use on other machines (same architecture)? I know how to do it on the same machine. But to use a compiled kernel other machines, is ...
0
votes
0answers
50 views

Problems configuring kernel

Trying to recompile my kernel and getting the following error to support Xen PCI Passthrough.It almost makes it through the whole build then flops out when building the image. dh_testdir ...
3
votes
4answers
7k views

How do I upgrade the Debian Wheezy kernel offline?

I using Debian (Wheezy) with the 3.2.0-4 amd64 kernel version and want to upgrade my kernel to newest version, like 3.13.3 stable, but I have no internet connection to my Debian OS. I have installed ...
1
vote
3answers
102 views

How to create a kernel source tree?

I am reading a book on creating drivers on Linux, I do not have too much experience with Linux, I have installed a quite a few distros before but I have always used windows as my main operating ...
1
vote
0answers
111 views

How to disable PAE feature of kernel, after installation?

I am using RHEL 5.3(x86) as a base platform for my development purpose.My machine's spec is as follows: Intel, Core-i3 Processor @ 2.5GHz 4GB RAM Problem is whenever I am attempting to install the ...
0
votes
2answers
70 views

How do you check the support for a specific CPU in the Linux or BSD kernel?

Assuming that I have the sources for my kernel and I know the name of a SoC or a CPU, how I can check that the hardware is supported without compiling and running ?
1
vote
1answer
1k views

Driver install, kernel source not found

I am trying to install a NVidia Cuda driver on a Amazon EC2. GPU instance (Amazon Linux AMI (HVM) 2013.09.2 - ami-e9a18d80) following the instructions laid out in a blog. It worked for the last two ...
1
vote
0answers
38 views

Patching the kernel source through git

I'm trying to understand how the patching of the kernel source works. I found the patch that I would like to try an apply on the following page. I found no .patch files that I can use to apply the ...
1
vote
1answer
216 views

What does this key code qualifier mean?

I know that in general this means that I have a "bad disk". But I'm after a more specific reason for why I am getting these messages from the kernel: sd 15:0:0:0: [sda] Attached SCSI disk sd ...
1
vote
0answers
68 views

kernel 3.1x and optimus support

I have encountered a negative observation regarding bumblebee. Namely, using optirun the performance of the GPU seems to be an order of magnitude lower than it should be. To be more specific: I have ...
2
votes
0answers
311 views

graph TCP connection performance based on `ss -i`

A nearby question has brought to my attention the ss utility on Linux, another utility to investigate sockets. It would appear that it may be a great tool to monitor the performance of, say, an ssh ...
1
vote
0answers
2k views

kernel: “echo 0 > /proc/sys/kernel/hung_task_timeout_secs”

I got this errors in syslog. Any idea what does it mean? The system is running on Ubuntu 12.04, kernel: 3.8.0-35-generic #52~precise1 It looks to me like failure when trying to write to disk... ...
0
votes
1answer
66 views

Patching linux kernel fails?

From what I understand, I can easily upgrade my kernel by applying patches to it, opposed to recompiling the kernel every time. I'm trying to go from kernel 3.2.51 to 3.2.54 by applying all the ...
0
votes
1answer
81 views

cc1 not in the PATH

I 'm trying to configure kernel via make menuconfig [Angstrom distribution] on BeagleBoard-xM, but I get these errors: make: Warning: File `/usr/src/linux-2.6.32.61/arch/arm/Makefile' has ...
3
votes
3answers
963 views

Why does MemTotal in /proc/meminfo change?

I monitor value from /proc/meminfo file, namely the MemTotal: number. It changes if a ram module breaks, roughly by size of the memory module - this is obvious. I know the definition for the field ...
0
votes
1answer
275 views

NFS: failed to create MNT RPC client status = -101

I am trying for network file system (NFS) booting between two systems. I am using dhcp server to assign IP-address for client. And my kernel and root file system are present in server. My client is ...
0
votes
1answer
54 views

How to install kernel sources

I 'm running Angstrom distribution (console only) on BeagleBoard-xM. Image was build on Narcissus, with Bootloader Files (x-load/u-boot/scripts) added. I noticed that usr/src directory is empty. I ...
2
votes
1answer
864 views

How to Find and reload specific driver from kernel?

I am using Crunchbang 64 bit O.S. with a ASUS N150 wireless adapter. Everytime I close my laptop and it enters sleep mode, when I "wake it up" I am unable to connect back using the wireless adapter, I ...
0
votes
1answer
128 views

Questions about behaviour of running LiveCD Linux after unmounting a CD-ROM

Could anyone explain what happens in system after unplugging CD-ROM during working with LiveCD session? Suppose that I'm using Ubuntu LiveCD and suddenly by accident the CD-ROM disconnect for a ...
2
votes
1answer
455 views

I want to understand Buildroot - the 3 compression config options (kernel, initramfs & rootfs)

I'm using buildroot to generate my images and for sure there is the option of compression with the help of different methods (LZO, LZMA, gzip, ...). So far i found these 3 compression options in ...