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

learn more… | top users | synonyms

7
votes
1answer
473 views

Can the 25 years of development of the Linux kernel be qualified or abstracted in layman's terms? [closed]

The Linux kernel is almost 25 years old. If I had to come up with the short version on the development history of the Linux kernel since 1991(its inception date), and in partcular since 1994 (1.0.0) ...
1
vote
0answers
17 views

insert module to kernel

I installed latest version of IPCOP, I've the correct module of my wireless card (htc_9271.fw): put it to /lib/firmware/ there is not any insmod/rmmod but only modprobe: modprobe htc_9271 FATAL: ...
4
votes
1answer
114 views

RTC time synchronization not working (CONFIG_RTC_SYSTOHC)

I have the option CONFIG_RTC_SYSTOHC enabled in my kernel: Device Drivers ---> [*] Real Time Clock ---> [*] Set the RTC time based on NTP synchronization The help says: ...
1
vote
0answers
48 views

Print list of bad blocks in NAND flash from user space

Is there any user space tool that can retrieve and dump the list of bad blocks in a NAND flash device? I've checked the mtdinfo command line utility, and also searched /proc and /sys, but couldn't ...
0
votes
1answer
79 views

Few questions about system calls and kernel modules (kernel services in parallel)

I have few questions about system calls and kernel modules. Let's assume we have two applications (A and B) and each of them is running on a different core. (A-CPU 0, B-CPU 1) When two applications ...
1
vote
1answer
105 views

Enabling ethernet over usb support in Linux Kernel

How to enable Ethernet over USB support in linux kernel. Which driver(like CONFIG_USB_USBNET) is related to this support. Is EEM (Ethernet Emulation) regarding this support or not..???
0
votes
0answers
18 views

Slow graphics when using kernel without module unloading support

If this is the wrong place for this question, please let me know. I didn't know where to ask, so here we go: Initially I wanted to disable module loading support for my linux kernel because I know ...
1
vote
0answers
94 views

Is it safe to disable Frequency Scaling and CPU idle Power Management support for Real Time purposes?

I'm using a Raspberry Pi board and I would like to build a real time system. During the kernel configuration, I found the CONFIG_CPU_FREQ option, which (from the help section) allows you to change ...
2
votes
1answer
416 views

TUN/TAP Will not load

I have an OpenVZ server but can't seem to get the tun/tap module to load. I ran modprode tun on the hostnode but when I go under the VM I get: Tue Sep 24 03:08:36 2013 Note: Cannot open TUN/TAP dev ...
3
votes
0answers
255 views

update kernel without restart

Recently Linux got a new feature called Live Kernel Patching, which you means you dont have to restart your system to update kernel. Is there any other kernel which has this feature already or Linux ...
4
votes
0answers
336 views

dmesg: pci BAR 7: can't assign io

I have VMware virtual machine running Debian Wheezy. I have compiled my own kernel 3.14. I have noticed dmesg is flooded with messages pci BAR 7: can't assign io (size 0x1000). I have no idea what ...
0
votes
0answers
44 views

Boot partition was unmounted during kernel update

So, I updated the kernel from 3.18.5-Arch to 3.18.6 and without mounting my boot partition. Now, no usb device (vfat not recognized) can be mounted and no network connection (no interface except lo) ...
0
votes
0answers
22 views

How to instruct RHEL6.5 Linux to save/starts states before crush or restart

I have multiple Workspaces, each responsible for different revisions of the same software. Not to have to recreate all Worspaces and open all tools/windows, I'm wondering how can I instruct Linux to ...
2
votes
2answers
41 views

Kernel panic if LUKS password is bad x times

Q: Is it normal if a RHEL 6.5 machine kernel panics if I type the LUKS password a few times wrong?
1
vote
1answer
117 views

lsof: measure I/O rate of a socket fd

I'm writing a script that parses the output of lsof to show a list of what processes have sockets open (similar to what netstat shows). lsof also gives me a file descriptor. What I want to do now is ...
2
votes
0answers
46 views

USB keyboard is disconecting automatically (without being unplugged)

In my log, I see following message: kernel: usb 1-1.6: USB disconnect, device number 5 acpid: input device has been disconnected, fd 7 acpid: input device has been disconnected, fd 8 I have not ...
1
vote
0answers
79 views

cannot locate header while making buildworld in custom kernel source

I'm trying to install a custom kernel in freebsd and here's step I followed: install freebsd 9.1 on vm from the image get the source from hardenedBSD (branch hardened/9/kernsep) execute "make ...
1
vote
0answers
55 views

Why doesn't Linux IPSec implementation support fragmentation before encryption?

I am trying to address an issue where ESP packets are getting fragmented as after adding the ESP header the MTU size is exceeded. The solution—which is what everybody does—is to do the fragmentation ...
1
vote
0answers
26 views

Kernel compilation for minimum program execution

Compiling the Kernel requires me to configure modules. I am unsure how to configure a Kernel which only supports following things: Programs compiled with gcc on other machines (glibc). I want to run ...
1
vote
1answer
64 views

What is “fs” short for in kernel function “get_fs()”?

There are two Linux kernel functions: get_ds() and get_fs() According to this article, I know ds is short for data segment. However, I cannot guess what "fs" is short for. Any explanations?
3
votes
3answers
13k 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)?
4
votes
3answers
12k views

mount.cifs : mount error(12) : Cannot allocate memory

I encountered this problem a while ago when upgrading my kernel but put off upgrading until now. On my system I can happily mount network shares using CIFS running kernel 3.7.10, however when I've ...
0
votes
0answers
17 views

Installing kernel headers (prior to `make install_headers`)

I'm trying to accomplish this make ARCH=x86_64 INSTALL_HDR_PATH=/opt/cross/x86_64-linux headers_install But with the 2.6.9 kernel tarball. It does not support the make target headers_install and ...
0
votes
0answers
179 views

Debian boot freeze (hard lockup)

I'm using debian sid and during two years i watch the same problem. When I boot from grub my system on the screen appears follow text: Linux kernel in decompress level...Parsing elf and then freeze ...
5
votes
2answers
154 views

How do you get hardware info and select drivers to be kept in a kernel compiled from source?

I would like to create a minimal kernel for a web server. When you compile a kernel from source how do you get hardware info and then know what drivers need to be kept in the kernel so the rest can ...
1
vote
0answers
15 views

How do kernel inform OSPF daemon when a physical interface status is down?

When a physical interface status is changed from up to down, there are 3 things related to the computer's current routing table and OSPF. The (connected) network for that interface and remote ...
1
vote
1answer
19 views

Kernel config: Is undefined the same as disabled?

Reading the Debian Kernel Handbook I came across the config option CONFIG_DEBUG_INFO. That option isn't in the official debian 3.2 kernel config, so what I'd like to know: If a certain option is not ...
2
votes
0answers
35 views

Improve kernel boot time

I am using OMAPL138 and kernel version 2.6.37 and I would like to improve the boot time. By analyzing the kernel boot process I think it is taking a long time at MII PHY CONFIGURATION. The printscreen ...
1
vote
2answers
140 views

Why is Linux “Unix-like” if its kernel is monolithic?

As I understand it, part of the Unix identity is that it has a microkernel delegating work to highly modular file processes. So why is Linux still considered "Unix-Like" if it strays from this ...
1
vote
0answers
35 views

Debugging info in linux kernel - how does it work?

I have found that I can compile linux kernel with some flags adding debugging support like CONFIG_DEBUG_INFO. These options while useful in debugging are also required by some utilities like ...
1
vote
3answers
67 views

Boot process - Dev sdX name changes

I had a Slack 13.1 machine with 2.6.36 kernel. Then, I updated the kernel to 3.12.1. This machine has connected: a bootable disk with three partions (/dev/sda1 --> Linux OS files..., /dev/sda2 --> ...
3
votes
1answer
111 views

Building a minimal linux

I have been following A Minimal Linux System from Scratch in order to build a Linux with a small footprint (10MB or less). I'm fairly certain that there were no errors up until the last point, where ...
2
votes
2answers
92 views

How to return 0 if a pattern is matched from a file? [duplicate]

I have a binary that repacks android kernel (not mkbootimg). I'm making a script to automate the process. I don't want any output on the screen. So I have redirected the output to a file named ...
3
votes
0answers
83 views

Can I masquerade a kernel uevent?

What I think happens From my understanding this is what happens when I connect a USB device to my computer: Kernel recognizes that I plugged in a USB device Kernel setups the very low-level things ...
4
votes
2answers
5k views

Kernel Panic - not syncing: VFS: Unable to mount root fs after new kernel compile

So I've been at this for a while and have been poking around for an answer for a few days, and figure it's about time to ask for help. I am running Ubuntu 10.10 in VMWare Fusion, and have downloaded ...
3
votes
1answer
143 views

Output shutdown messages to multiple consoles

I have configured my system to direct console output on boot to serial and vga using kernel parameters. Serial is the last argument in the kernel parameters and will be the default used for ...
2
votes
0answers
754 views

Install rtl8188etv/rtl8188eu driver on Orange-Pi

I'm trying to install the wifi driver on Orange-Pi board. The real chip is rtl8188etv but the driver is the same. I have compiled 3.4.105+ Kernel to have the headers: mkdir ...
2
votes
0answers
55 views

View syscalls/kernel activity for I/O from a running process

I'd like to be able to view syscalls or kernel activity for a process...I'm not actually sure of the terminology I need here! Specifically I'm looking for the difference between I/O going to local ...
2
votes
1answer
45 views

What is /proc/filesystems supposed to be and why is it different from /lib/modules/linux_ver/kernel/fs?

The very little documentation about /proc/filesystems says it is a "list of supported file systems". I see a lot of file system modules in /lib/modules/linux_ver/kernel/fs, most of which do not appear ...
1
vote
1answer
108 views

Missing kernel headers, but need them to install the Wifi driver

I am trying to install Kali on my Lenovo Yoga13, but after formatting the disk the setup failed to install grub because of no internet access (no Ethernet, need driver to get Wifi to work). So, I ...
4
votes
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 ...
1
vote
1answer
115 views

Cannot update new kernel for CentOS 7 although the server have space enough

I try to update kernel on my CentOS 7 but the yum say there is no space enough on /boot although /boot have 343 MB as show below: Filesystem Size Used Avail Use% Mounted on /dev/sda2 477M 105M 343M ...
12
votes
2answers
922 views

Is it good to have multiple version of Linux Kernel?

Once, I was installing some kernel patches & something went wrong on a live server where we had hundreds of clients. Only one kernel was there in the system. So, the server was down for some time, ...
3
votes
2answers
418 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 ...
1
vote
1answer
124 views

How to manually compile Fedora 20 kernel

I am trying to recreate an environment for debugging purposes. I require Fedora 20 specific kernel version (in this case its 3.17.7-200.fc20.x86_64). I have manually compiled vanilla kernel (3.17.7) ...
1
vote
1answer
163 views

can't filter printk messages

I'm writing a driver and usually I implement my own log-level scheme. However, this time I figured that I would try to utilize the printk scheme that is built into Linux. I see that I can adjust the ...
1
vote
2answers
8k views

Partition table not recognized by Linux kernel

I experience relatively often that the partition table of a USB stick or SD card is suddenly no longer recognized by the kernel while (g)parted and fdisk still see it, as do other systems. I can even ...
3
votes
1answer
125 views

bash runs out of memory

This question is a fork of this SO question. Here is the MCVE version: $ PS1='Parent-$ ' Parent-$ type seq seq is /usr/bin/seq Parent-$ bash $ PS1='Child-$ ' Child-$ for i in $(seq 1000000000); do ...
58
votes
5answers
33k views

What are high memory and low memory on Linux?

I'm interested in the difference between Highmem and Lowmem: Why is there such a differentiation? What do we gain by doing so? What features does each have?
1
vote
0answers
98 views

Using DKMS, to automatically patch and install kernel on update

I have a system that needs patching a file in kernel to work properly. The system is running Ubuntu 14.04. The patch patches a file in drivers/hwmon. So after every kernel update I need to download ...