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

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456 views

How can I tell if I have a bug with my kernel or with my UEFI firmware?

I have a dz77ga-70k motherboard with version 0049 of the Intel firmware on it. Linux and elilo will not boot in uefi mode. The symptoms are that when I run bzImage.efi initrd=initrd.img ro debug ...
4
votes
1answer
169 views

How are Linux kernel compile config's determined?

I am compiling my first Kernel (3.5 rc1) from source through menuconfig. Certain configuration options are pre-set. Who / what determines if they are pre-set? Does the make menuconfig somehow ...
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0answers
151 views

memtester runs faster after couple of runs

I am using this test tool : http://pyropus.ca/software/memtester/ And I noticed that first 3 iterations take 4 hours but 30 iterations take only 12 hours. I was hoping that 30 iterations will take 40 ...
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0answers
203 views

how can one program an operating system from scratch? [closed]

My programming skills are still rudimentary but I'm curious to know how can one program an operating system from scratch . I know that one must understand how the hardware of the computer work and how ...
3
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3answers
284 views

Should I update my Fedora or not?

Here is my problem. My laptop has an NVidia Geforce 310 M graphic card. And since kernel 2.6 I had problems with the display. I had to use nomodeset option in the grub, if not my screen will be off ...
3
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1answer
2k views

Does Linux log when a process is started, and the PID that gets assigned to it? Where can I find that log?

When my Ubuntu server starts up, I see a message that says: kernel: [11.895392] init: failsafe main process (631) killed by TERM signal. I would like to know what process this is but I'm not sure ...
4
votes
1answer
209 views

Writing a driver to fool *nix systems about having a GPU

I'm into something about writing a "Mock GPU driver" for *nix based systems. What I mean is that, simply I want to write a driver (Behind X-server obviously) to answer X's API calls with some ...
2
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2answers
1k views

GParted LiveCD: Is there a version with a 64-bit kernel?

I'm trying to chroot with the GParted LiveCD onto an existing 64-bit system, attempting to fix grub.
6
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3answers
3k views

How to read the in-memory (kernel) partition table of /dev/sda?

I accidentally overwrote my /dev/sda partition table with GParted (full story on AskUbuntu). Since I haven't rebooted yet and my filesystem is still perfectly usable, I was told I might be able to ...
2
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2answers
578 views

SIOCSIFADDR: File exists after upgrading kernel

Since upgrading my (Gentoo) kernel from 2.6.38 to 3.3.8 (via oldconfig), I can't get the network on eth0 up anymore. It reports "SIOCSIFADDR: File exists" with a number of other SIOCSIF* errors that ...
3
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1answer
131 views

How to submit a Linux module upstream?

I've written a useful kernel module for a specific fan controller that I want to submit upstream. Where can I find an address to submit my module? Do I need it make GPL or can I use a less ...
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2answers
1k views

An oom killer thats baffling me

I am not able to understand why would kernel issue this oom killer when I see enough memory is available: Also why are there so many kernel cache pages allocated? I say enough memory is available ...
4
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4answers
180 views

Why are Linux installs bigger than I've read? Some beginner questions

I've read in different textbooks that say Linux is light-weight(e.g. It could fit on a 1.4MB floppy). So why is the download from the Ubuntu or Fedora CD sized or larger? Do the device drivers extend ...
5
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3answers
1k views

Does /init (or /linuxrc) script creates temporary device nodes in /dev?

Considering that GRUB executes following lines: kernel /vmlinuz root=/dev/sda1 ro initrd /initrd On boot, how does the Linux kernel finds out about /dev/sda1 device node? I know that ...
4
votes
4answers
3k views

Cannot create “Hello World” module (and NVIDIA, and VirtualBox)

First off, the details. BEFORE: kernel: 3.2.0-2-amd64, nvidia driver: 295.59 AFTER: kernel: 3.2.0-3-amd64, nvidia driver: 302.17-3 My Debian wheezy is kept recent at all times. Actually, doing ...
5
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2answers
1k views

How to know which firmware is loaded by kernel?

I have an Intel wireless card driven by iwlwifi, and I can see the following message in dmesg: iwlwifi 0000:03:00.0: loaded firmware version 17.168.5.3 build 42301 But how do I know which firmware ...
4
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1answer
494 views

Is it safe to use customized CFLAGS for linux kernel, e.g mmx sse instructions

Is it safe to use customized CFLAGS while compiling linux kernel, e.g enable SSE, MMX instructions, is that a problem ?
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2answers
2k views

Can I detect if my custom made kernel was built with module support?

I have been provided with a vendor supplied minimal linux installation. From an answer to a previous question I discovered that it is possible to build a kernel with or without module support. I have ...
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0answers
457 views

Linux thin station

I have this pc that I just installed and set it up as Linux thin station. I did all the formatting procedures and copying of image to the HD. When I boot it up, I get these, which I think are driver ...
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0answers
86 views

How to deal with closed source modules when configuring a new kernel build

I found this command very useful: make localmodconfig However, having some closed source drivers/modules ends up being a problem because this command can't find an appropriate way of including the ...
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2answers
289 views

yum is asking the kernel version which is already there

I have a server with centos 5.3 x86_64 on it. I am trying to install some asterisk modules on this server using yum. So yum asked me to upgrade my kernel to "kernel-2.6.18-308.11.1.el5" Then i have ...
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0answers
62 views

What are the differences between the current Linux kernel and the Unix SVR4 kernel in terms of device drivers+i/o and virtual files systems?

Yes I realize that Linux supports many more file systems and recognizes more devices than Unix SVR4. I'm interested in what the differences are in the abstraction on top of an actual file system, or ...
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2answers
356 views

Do Solaris 10 and 11 still use slab allocation for their kernel memory allocator

If not, what do they use. Please provide a source.
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0answers
103 views

How to find where driver.mod.c links to?

I'm trying to port the webcam composite gadget from kernel 2.6.37 to 2.6.32. I don't have a choice on this since I depend on other drivers and a SDK which only compile for this version. My train of ...
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2answers
1k views

Does Linux kernel 3.x use the CFS process scheduler?

Does the latest version of the Linux kernel (3.x) still use the Completely Fair Scheduler (CFS) for process scheduling which was introduced in 2.6.x ? If it doesn't, which one does it use, and how ...
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1answer
1k views

How can I use netconsole to help solve a kernel panic?

When I try to use a raid as root, my system panics. I want to read the kernel output right before the panic, but can't scroll up. After Googling a bit, I wanted to try netconsole. but I get no output ...
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2answers
290 views

How am I supposed to keep up with kernels as a developer?

I'm developing for a specific TI ARM processor with custom drivers that made it to the kernel. I'm trying to migrate from 2.6.32 to 2.6.37, but the structure changed so much I will have weeks of work ...
2
votes
1answer
759 views

High memory (user space) and highmem (kernel space)

Each process has 2 memory area: User space (high memory) and kernel space (low memmory). In the kernel space, are the first 896 MB used for mapping kernel code (not fully 1 GB)? This means, when a ...
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0answers
405 views

Can I apply real time Linux kernel patch on Android kernel?

I would like to apply real time patch on the Android kernel (given I've found Kernel patch for corresponding Kernel version). Is it possible or should I create a patch specifically for the purpose of ...
4
votes
1answer
409 views

When should I keep debugging symbols in kernel modules?

When installing kernel modules, I have the option to strip out debugging symbols using INSTALL_MOD_STRIP=1. This saves significant disk space. Does it also save memory? Why should one keep the ...
5
votes
2answers
1k views

Booting a newly compiled linux kernel

I have started reading the book Essential Linux Device Drivers. I am following the process for compiling and booting into a new kernel. However I am unable to boot into the newly compiled kernel - I ...
2
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1answer
261 views

Automatically update a Debian system

I want to automatically update a Debian system (actually Debian Wheezy on Raspberry Pi, though that shouldn't make much a difference). I've already seen that there is cron-apt, probably a good choice, ...
5
votes
1answer
3k views

How do I convert a kernel .config file from 32-bit to 64-bit?

At this page you can download a configuration file that lets you target a particular notebook architecture during the compilation of a new 32-bit Linux kernel. I need a 64 bit version. What do I ...
0
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1answer
2k views

How can I generate /proc/vmcore?

I want to practice with makedumpfile. However, it needs /proc/vmcore which is the memory image of the currently running kernel. Also, reading the man page of makedumpfile, we also need 2 kernels: ...
1
vote
1answer
136 views

Choose kernel for specific hardware

I have old system with an AMD Athlon 1,2 GHz processor and [SiS] 65x/M650/740 graphics (output from lspci). Recently I discovered on a german ubuntu page that since version 10.10 some older ...
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1answer
873 views

Is Native Language Support (NLS) kernel support still necessary?

Does ext4 / cifs system need kernel NLS support ? I'm not sure if it's being handled by user-space program (decoding / encoding) ?
4
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2answers
2k views

How to know if a network interface is tap, tun, bridge or physical?

As far as i know, there are 4 main types of network interfaces in linux: tun, tap, bridge and physical. When i'm doing sys admin on machines running KVM, i usually come accross tap, bridge and ...
1
vote
1answer
256 views

Edit the .config file when en/disabling a particular option like CONFIG_CPU_FREQ?

From here: http://www.xenomai.org/index.php/FAQs#Which_kernel_settings_should_be_avoided.3F Which kernel settings should be avoided? Note that Xenomai will warn you about known invalid ...
6
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1answer
1k views

WARNING: modpost: Found 10 section mismatch(es)

Is this error message something that I should be worried about? linux-y3pi:/usr/src/linux-2.6.38.8 # make modules scripts/kconfig/conf --silentoldconfig Kconfig CHK include/linux/version.h ...
4
votes
1answer
1k views

How to know whether the Linux driver for the real-time network device was built into the kernel?

From here: http://www.xenomai.org/index.php/RTnet:Installation_%26_Testing#Debugging_RTnet The Linux driver for the real-time network device was built into the kernel and blocks the hardware. ...
1
vote
1answer
290 views

install 2.6.32.59 on squeeze

I'm suffering from a kernel bug in a production environment. The problem isn't causing a complete outage, but it's degrading service. These are soft lockups. I'd like to try a newer kernel, ...
3
votes
1answer
491 views

Is it necessary to enable CONFIG_USB_OHCI_HCD , when there's only USB 2.0 ports

Is it necessary to enable CONFIG_USB_OHCI_HCD on a system that has USB 2.0 port only ? I'm not sure those devices present , e.g bluetooth , camera use that driver ? Bus 001 Device 001: ID 1d6b:0002 ...
1
vote
1answer
284 views

Where is CONFIG_APM in kernel - 2.6.38.8

From here: http://www.xenomai.org/documentation/xenomai-2.6/TROUBLESHOOTING Q: Which CONFIG_* items are latency killers, and should be avoided ? ... APM: The APM model assigns power management ...
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vote
1answer
97 views

ACPI (Advanced Configuration And Power Configuration) not present on 2.6.38.8?

I need to disable some parts in ACPI, but it is simply not present in kernel 2.6.38.8 (downloaded as a tar from net)? I can see the option in kernel 2.6.34-12 (default on OpenSuse 11.3), but not in ...
0
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1answer
544 views

buildroot/busybox: launch bootchartd on startup

I built a custom linux image using buildroot and busybox. To speed up the boot process I'd like to use bootchartd (built-in version of busybox) to profile the process. However bootchartd is not ...
1
vote
1answer
156 views

how to enable sound support in linux kernel without recompile?

I have recently compiled linux kernel 3.2. But at time of compiling in make menuconfig, I had disabled sound support. Now, I want to enable it without recompile it. I don't want to use stock kernel ...
2
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3answers
483 views

Why does Linux on sparc64 architecture use 32-bit pointers in user-space and 64-bit pointers in kernel-space?

What are the advantages of deviating from the norm; that is 64-bit pointers in both user and kernel space for a 64-bit architecture? Reference: http://lwn.net/images/pdf/LDD3/ch11.pdf (Page 2)
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0answers
627 views

Qemu doesn't boot kernel after “Uncompressing Linux… done, booting the kernel. ”

I've compiled qemu for s5pc110 (it's from http://gitorious.org/samsung-linux-platform/qemu, somebody had added support for s5pc110), version 0.12. But when I load the kernel: qemu-system-arm -M ...
33
votes
4answers
46k views

How to reload udev rules without reboot?

How should one reload udev rules, so that newly created one can function? I'm running Arch Linux, and I don't have a udevstart command here. Also checked /etc/rc.d, no udev service there.
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3answers
2k views

Why don't you need to update drivers? (Or do you?)

In my life I've not once updated drivers on any of my Linux systems, though they have all been desktops. A friend was asking me why one does not need to update Linux drivers and I found myself unable ...