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

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1answer
6k views

Excluding kernel modules through /etc/modprobe.d/blacklist.conf does not work

I don't want to load the kernel module nouveau on my debian box at startup, so I put the following in /etc/modprobe.d/blacklist.conf: blacklist ttm blacklist drm blacklist nouveau I even did a ...
2
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1answer
1k views

What is user address space and what is it's purpose?

I am reading about processes. I came across a topic "How a process is created" wherein I encountered the following :- The process image as viewed by the kernel runs in its own user address space ...
1
vote
1answer
1k views

Assembly files in obj-m list when building kernel modules

I'm trying to build kexec as a module, but I'm running into a weird problem. My obj-m is: obj-m += kexec.o machine_kexec.o relocate_kernel.o When I run the makefile, it complains that there's "no ...
1
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1answer
521 views

Can kexec be built to a standalone binary, to be used where kexec was not built into the kernel?

I have remote embedded Linux devices I am trying to update to a new kernel without having to physically access. However, the command line options they boot with make one of the MTDs read only - I ...
18
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2answers
5k views

How to blacklist a correct bad RAM sector according to MemTest86+ error indication?

MemTest86+ (the version included with Ubuntu 13.04) says Failing address: 002f796c48 - 759.5 MB What should I specify in the memmap kernel parameter to bypass this area? I've tried running ...
2
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3answers
149 views

What considerations need to be made when choosing the version of kernel for an embedded device?

I have used buildroot to successfully create a kernel, root file system and cross-compilers to enable me to write application code to run on an embedded device. Currently I have no need to write ...
0
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1answer
635 views

debian cannot install kernel source

I want to use debian linux for my laptop again. So I took my old debian 6.0 cds and installed it. From the last time I know, that I have to build the driver for my Atheros AR8151 Gigabit Ethernet ...
0
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0answers
664 views

*ERROR* timed out waiting for panel to power on

I'm using Ubuntu 13.04 on Asus VX6 (1.8GHz Atom - 2 cores, optimus nVidia ION) with Kernel 3.9.0. When I start my system I get this error: [ 15.728106] [drm:intel_enable_lvds] *ERROR* timed out ...
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0answers
73 views

Decreasing mouse sensitivity at kernel level

I have developed a custom-GUI Server, which runs on virtual console of Linux.For mouse-handling purpose, it reads the mouse device file /dev/input/mice and retrieves the event data and updates ...
4
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1answer
283 views

Does the vmlinux header contain the length of the kernel image?

I am trying to disassemble a compound file that consists of several parts, one of which is an uncompressed kernel sandwiched between several other files. I am trying to find the exact length of the ...
1
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1answer
776 views

Booting encrypted root partion fails after system update

I have a problem booting my Debian Linux server. After a system update, GRUB loads the initrd and the system should ask for the password, but it doesn't. Instead, I get dropped to BusyBox. After ...
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2answers
2k views

Sign a module after kernel compilation

I've built a kernel in tmpfs, then I rebooted. Now I see a message when I compile the 3rd party module, NO SIGN [M] XXXX.ko How can I get it signed? The key pair generated during rpmbuild is lost ...
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2answers
285 views

Why is the UNIX kernel so crucial? [closed]

More specifically, how is the UNIX kernel treated differently from other parts of the Operating System?
0
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1answer
278 views

Understanding a XINU system call - getstk.c [closed]

I am having trouble conceptually understanding what is going on towards the end of this system call, and why. I understand the getstk.c method returns the highest memory address of available space, ...
4
votes
1answer
326 views

Making a recovery partition in embedded Linux

I have an Atmel SAM9X system running Angstrom. I am trying to make a recovery partition so when a user holds a button during boot up the recovery partition boots up. I have modified the bootstrap so ...
8
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1answer
6k views

How can I mount filesystems with > 4KB block sizes?

I have a 3TB hard disk pulled out of a WD Mybook Live NAS. The partition table is as follows: Model: ATA WDC WD30EZRS-11J (scsi) Disk /dev/sdb: 3001GB Sector size (logical/physical): 512B/4096B ...
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2answers
312 views

Does linux modules/drivers belong to kernal space or user space

Some articles say that modules/drivers belong to kernel space as it take part in forming the kernel; (reference: http://www.freesoftwaremagazine.com/articles/drivers_linux) While others say that ...
1
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1answer
350 views

ixgbe: increase rx performance

I have an Intel 82598EB 10GBE NIC. I need to receive traffic without packet loss. Data rate is 4-5 Gbps, packet size is 1500-9600 bytes. I had already configured smb and irq affinity. I also tried ...
3
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1answer
184 views

How to measure the clock pulse of my computer manually?

My PC has two processors, and I know that each one runs at 1.86 GHz. I have just read about clock cycles and I only have a (very) rough understanding, so I apologize beforehand if my question is so ...
3
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3answers
12k views

what is pts/0 and (:0.0) in linux by type who am i

When I type the command: [root@degeneration Desktop]# who am i root pts/0 2013-04-12 15:08 (:0.0) What is pts/0 and what is meant by (:0.0)?
0
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2answers
41 views

can't update with this error messg

I got this message: not enough free disk space.... The upgrade needs a total of 31.8 M free space on disk '/boot'. Please free at least an additional 31.8 M of disk space on '/boot'. Empty ...
12
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1answer
338 views

Can entropy consumption at program start be prevented?

I use Knoppix (or other Live CDs/DVDs) as a secure environment for creating valuable crypto keys. Unfortunately entropy is a limited resource in such environments. I just noticed that each program ...
0
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2answers
2k views

What are “kernel data structures”?

While reading about the Linux kernel I came across the notion of kernel data structures. I tried to find more information via Google, but couldn't find anything. What are kernel data structures? ...
6
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1answer
478 views

Would someone please explain lspci -vv output?

I have the following output from running lspci -vv -s 00:00 on my single board computer running Linux. 07:05.0 RAID bus controller: Adaptec AAC-RAID (Rocket) (rev 03) Subsystem: Adaptec ASR-2230S + ...
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1answer
897 views

Only output errors / warnings when compile kernel?

When you compile kernel you normally see lines like CC XX.o or LD XX So, can I skip these messages? Only output errors or warnings generated by gcc
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2answers
255 views

Locate occasional CPU kernel hog

I have a 2.6.35 PREEMPT kernel running on moderate-speed ARMv7 processor. About once every 100 - 125s, something causes the kernel to fail to process some audio-related drivers sufficiently quickly to ...
3
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2answers
3k views

Why does modinfo say “could not find module”, yet lsmod claims the module is loaded?

According to the man page of lsmod the command shows “what kernel modules are currently loaded”. I wrote a script that uses modinfo to show what kernel object (.ko) files are actually in use: ...
2
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0answers
845 views

Unable to install the selected kernel

I have problem with my DVD drive. It's corrupted and when I'm trying to install Ubuntu it stucks (even with the miniISO) I was able to successfully start the OS from system rescue CD. I'd like to ...
0
votes
1answer
353 views

How to troubleshoot high kernel time (high network usage; high interrupts)

I've noticed that I have high kernel time when doing a lot of network traffic in Linux. I also noticed that 45% of my CPU is spent doing interrupts. How can I further troubleshoot this?
0
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1answer
139 views

Force Debian kernel version

I need Debian with kernel 2.6.34.8 Is there any way to force Debian with it? I don't want to install and then compile version I need.
3
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2answers
195 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 -> ...
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0answers
26 views

Figure out which distro I'm using with Zsh script [duplicate]

I'm making a script that installs some basic needs of mine on my newly installed Linux. However depending on the Linux distro the contents and commands would be different. In Arch Linux I would use ...
0
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1answer
162 views

How to create a debian 3.x kernel rootfs on a 2.x host

I'm trying to build a rootfs for an embedded A10 board. This will be matched up against 3.0.62+ modules and a corresponding vmlinux image. I've been trying for a few days to get a rootfs set up for ...
4
votes
2answers
1k views

How do I determine ZCACHE works on my box?

I have an Marwell Kirkwood ARM-based NAS server Zyxel NSA 310. I compiled my own 3.8 kernel and enabled ZCACHE, but I still see 256 MB of RAM. I am not sure if GNU free utility should show extra ...
1
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1answer
330 views

Where to start profiling Linux kernel?

What are the standard and conventional ways of profiling the Linux kernel? I know there is perf tool but is there anything else?
1
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1answer
228 views

What information exactly is in the access control bits of a page table?

I'm currently learning for an exam in operating systems. This includes learning some basics about page tables, which lead me to the question Why using hierarchical page tables? which mentions that ...
0
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1answer
84 views

Relation between the kernel version and OS version

I am running a Ubuntu of version 12.04. Can I use a kernel of version of version 2.4 on it?
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2answers
46 views

Kernel compilation of version 2.4 on a system running 3.2.0

My current kernel version on with my OS running on is 3.2.0. Can I compile a kernel of version 2.4.0 on it? Is there any perfect kernel documentation available? (As I see different ways of compiling ...
4
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2answers
735 views

kernel module function call

I write a kernel module which has initialize and end function. I want one more function and want to call it from the user space process at any time i want. Is it applicable ? If so, how ? I am ...
2
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5answers
240 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 ...
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0answers
186 views

Pinnacle TV tuner card, readreg error, dvb_register failed, cx8802 probe failed, firmware never loads

I'm trying to make this card work in a touch screen kiosk running Ubuntu 10.04, kernel 2.6.32-45-generic This card seems to use the s5h1411 chip instead of the s5h1409 the modules are expecting. I've ...
0
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2answers
258 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 ...
2
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0answers
140 views

Is there a way to undo VGA adapter modesetting in Linux

I'm looking for a way to reset the graphics adapter to textmode after it has been set to some sort of graphical mode by the kernel on bootup, and possibly used by an X server. Is there any code to do ...
1
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1answer
92 views

How to give an ordinary user privileged access to a particular syscall in FreeBSD?

I want to give an ordinary user the ability to fchown() files arbitrarily (as if they were the superuser) on FreeBSD. Generally speaking, is there a right way to change the privilege-checking of a ...
0
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0answers
180 views

pptp differs between 3.7 and 3.8 linux kernel milestone with 3.2.0-4 milestone

Unfortunately, current kernel of debian has problem with my hardware: 3.2.0-4-686-pae , and when i compile one of 3.7.x milestone or 3.8.1 itself , my problem is solved. But my problem with new ...
2
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2answers
227 views

Linux kernel development for multi core architecture

I am working on a project adapting system software like the Linux kernel. I read one paper titled "Experience on Comparison of Operating Systems Scalability on the Multi-core Architecture" that tells ...
0
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3answers
782 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 ...
15
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3answers
13k views

How to cause kernel panic with a single command?

Is it possible to cause a kernel panic with a single command line? What would be the most straightforward such command for a sudoing user and what would it be for a regular user, if any? Scenarios ...
5
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3answers
157 views

Control how linux deletes files

What exactly happens when an application deletes a file? Is there any way to control this behavior? Basically I want to shred instead of rm in all cases, but of course applications do not make calls ...
0
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1answer
218 views

How does kernel swapping / INT 13h interrupts work?

I'm looking for a way to learn about and understand this technique. Here's what I'm talking about: Slax boots, {does stuff, like copy itself to RAM}, then transitions control to the kernel/file ...