I want to know what are the advantages and disadvantages for accessing spi(serial peripheral inerface )from kernel level and user level. like methods of doing it, speed ,memeory utilization etc
View 1 RepliesWe all know linux kernel base layer is made up of structures, in which every object of kernel is well defined. Structure members correspond to object properties required to define object behavior.
For example if we take case of File system.It composed of four objects , superblock objects, inode objects, file objects and dentry object.Each having well defined structure which is being operated by system call handler and by system call service routine in the kernel mode.
Now my question is even in kernel mode we do not have some mechanism by which we can get access to pointer of these structures.We have some macro.
If I want to manipulate structure on my on way, or performing some more operation defined by me.For example after the crash of Hard Disk Drive, having ext2/3 file system, If i want to know all the inode pointers, and block details.
Can I have some way out to do desired operation ??
mechanism to operate on these base label structures, even in kernel mode ..
I've been able to kludge a kill script which finds the correct pid for the kdeserver (or gnome server) after my system comes up in run level 5 so I can drop back to run level 3 mode. Lots of experimentation showed me that using telinit 3 and telinit 5 would occasionally leave the video memory in a mess and I would have the black screen of death.
I set the security parameter setting to autologin for me since I am the only user of my machine, but I still have to kludge the default setting under sysconfig (the DEFAULT_WM) under Window Manager to pick a certain window manager, so it takes time to manually switch the desktop.
Right now I can leave the gui and drop back to cli, but painful experimenting showed me that killing the X server is a no no. Right now I kill the kde server, which sends the SIGTERM to the X windows manager, which then figures out that it has to shut down.
Questions: Is there a better way of doing this? Apparently openSUSE figures that we have multiple users logging into the gui desktop, so the gui is always kept running and a login window with the desktop manager option forces the user to login in. With autologin, this never happens, but no choice of desktop is possible on the fly.
Can some type of script be set up to painlessly enable this to happen? And what is the best way of bringing either the Gnome or KDE desktop manager down gracefully? I do get lots of error messages as the system attempts to recover and X shuts down. It appears that apparently the single user with autologin is left out in the cold.
I want to install a software called TinyOS which is an operating system designed for wireless sensor embedded networks in my account. The problem is it has instructions to install the software as an administrator since i'm not an admin of the department network i can not able to install. Is there any method to install this software as an user level rather than admin level.
View 3 Replies View RelatedMost kernels are written in low level programming languages such as C and Assembly. Would it be possible to write a kernel in a high level language such as Python? Many high-level languages are themselves written in C.
View 5 Replies View RelatedHow can I adjust the levels at which the battery is considered to be critically low?ight now it seems this is set at 5 or 10%. I want to make it 20 or 25%This is for Gnome. I am using Lucid x86
View 1 Replies View Relatedhello everyone, im having a problem when my computer enters in the run level 4 as the default when i start slackware. The strange thing is that it not seems that is a X window problem, it looks like more like a configuration problem in some part of the kde script to initialize the log in, because if i manually start the X service it works fine, i dont know what is the source. Thank you in advance for the help.
View 3 Replies View RelatedI would like be able to access packets coming off the network with the hopes of coding a primitive packet sniffer for learning purposes. I would also like to be able to piece together my own packets and send them out on my network. Eventually, I would also like to write a simple firewall so I want the capability to drop packets as well as let them pass. I assume I will have to access the kernel with some system calls to do this, any one have any information or resources that could help me on this project?
View 1 Replies View Related[code]...
you can find a cutout of an output generated by "iwlist s" command for a cell. Does anybody know what Quality, Signal level and Noise level mean? What is the definition of them? I searched for it and could not find good information on it. What do these Extra:*** fields for? What does it show in the example above? How were those values computed?
[code]...
Hi Guys,
here is my scenario:
I am running F10 x86_64 with Nvidia Quadro FX 3400.
I installed the drivers and it worked just fine. No errors generated according to Nvidia log files.
However, while in run level 5 when I try to switch to run level 3 by typing "telinit 3" or "init 3" the X server goes down and I get a blank screen. Same thing happens when I try to switch to a different tty session by <ctrl>+<alt>+F2 (or any F key for that matter).
I also noticed that when I shut down my system I can't see any more the screen where services are shutting down and their status ([OK] or [failed]).
Would appreciate your help on solving this issue.
Hey Guys, I'am new here and request your help on this:
After installing emacs and a few dependencies on my RHEL 5, on restarting the system, the keyboard was not able to work. I restarted several times in vein.
However, when I start in single mode, it works perfectly. I have tried looking for a solution from google, but in vein.
Kindly help...
Regards, Andrew
I have a directory that has a another directory inside it. The top directory is rather redundant since it only contains the one other one. Is there a way to delete the top level directory and have the contents simply "move up a level"?
View 6 Replies View RelatedI just upgraded to the 10.04 and everything works just fine as before (except for skype but that really doesn't matters as it has already been 3 years I'm using ubuntu and I managed to get it to work only once, for miracle I believe ^^). The only real issue I have is this: when I start up my laptop, after the log-in, no sound will be heared as the "speaker" volume level in alsamixer is set to 0; if I raise it from the terminal running alsamixer (as I don't know any other alternative) everything plays just fine, but the next time I boot I do have to do it all over again... So, how can I change the default startup level of the "speaker" in alsamixer?
PS: by the way I do have the very same issue with the screen luminosity but the other way round as is always starts at maximum brightness and I can't manage to get it to start at the minimum, as it did before. At least reducing the backlight if far more quick but a couple of times I forget it and the battery lasted something like half an hour
We are using Red Hat Enterprise AS 3.0. There are 100+ users connected to a single server. As the Inbox size of Mail Client (Thunderbird) for each user grows there are space constraint on the server. So I want to define a quota on mail folder for each user (say around 500 MB to 1 GB). How can I do this.
View 3 Replies View Relatedi am trying to setup a very basic samba share on RHEL.after editing smb.conf ,testparm output is ok,(though it shows STANDALONE SERVER.)the directive i have used are
workgroup=MYGROUP
hosts allow=192.168.0. //my network
[storage]
path=/var/ftp
[Code]...
I'm running Debian Lenny. When I exit run level 1 (single user mode), the system automatically continues into run level 2. I have browsed the init scripts and have yet to determine how this "magic" is performed. I would be grateful if a local guru would point me to how the scripts automatically proceed into run level 2 when exiting run level 1
View 4 Replies View RelatedFirst, I am new to linux I just finished installing Fedora 14 on a different PC which I will be using solely to explore Linux. However the first annoying problem I encountered was that I can't do a lot of things without Linux asking me for the root password. This has become really annoying, I want to stop fedora from asking for root authentication every time I want to explore something here and there.
Among the work-arounds that I've tried and didn't quite work for me are:
1. login as root on the kdm - I can login as root but because I am also encouraging my sister to explore fedora 14 she needs the same access as root too. We have our own preferences so we both need individual accounts that have same access level as root.
2. change userid to 0 (same as root) and modify groups to be exactly the same as root's groups - very bad solution, what it did was make my user a sort of "alias" for the root. It basically uses the same /root/ folder, same settings and all that stuff. Again, my sister and I need separate accounts for a more personal feel.
3. use terminal and go sudo, sudoers, etc - very bad idea, I want to explore using the kde gui. And again I want to eliminate the inconvenience of having to type things over and over again. I'd rather type the password over and over again than having to use terminal and sudo everything.
4. beesu, gksu - anyone knows how to make linux automatically wrap everything with beesu/gksu?
since we are just exploring, we are willing to trade the systems, integrity and security for the convenience of having freedom to explore everything in it. I don't care, it could blow up the pc for all I care (it's old and for experiment anyway).
This exploring linux of ours is a make or break for us to using linux. If there is no solution to this problem, we'll probably scrap the whole "migrate to linux" idea.
I thinking of making Linux recognize our user id the same way it recognizes uid 0 but I have no idea how to do this.
I am currently having issues with system freeze when unmounting portable hard drives. This happens almost every single time. Normal USB sticks are fine and do not produce the freeze. I am using kernel 3.0.0-rc6, however the issue also persists when switching back to 2.6.39. This is the error message i get when freeze occurs, reverting to terminal output:
WARNING! power/level is deprecated use power/control instead
Jul 13 18:26:49 destiny kernel: [ 6196.892776] Call Trace:
Jul 13 18:26:49 destiny kernel: [ 6196.892803] [<ffffffffa008feec>] ? scsi_setup_blk_pc_cmnd+0x15/0x104 [scsi_mod]
[Code]...
I am writing a device driver and want to debug it using KGDB.Could anyone tell how to install and debug with KGDB on Linux 2.6.35 distribution?
View 2 Replies View RelatedI am learning about net filters and I am practicing some sample programs on it. I am very new to this and I have a general query. I got the packet to a desired function using PRE_ROUTING hook. Now how do I frame a packet from this point? I am just trying to simulate a echo client server program in the kernel level using these hooks. Any useful info on sockets in the kernel level?
View 1 Replies View RelatedI have gone thorugh some documents about pthread (NTPL ) in linux 2.6 kernel. As per that linux uses 1: 1 threading model and for each user level thread there is kernel level thread. Pthread_create uses clone system call to create a LWP and the kernel could treat that as a LWP and do scheduling and all .( different from linuxthread). My question is what's meant by there is kernel level thread for each pthread created. Can I see the kernel level thread if I call pthread_create using ps .
What exactly meant by 1:1 .I mean for each user level thread there is kernel level thread . If I make a system call from a thread does the OS services that action via kernel thread ( created using kernel_thread () or some other way ) internally ..
I am searching for a Linux user level command/utility to measure the network bandwitdth used by a specific process by usig its process id.i used different commands like, iperf, ntop, netstat etc, but it doesn't to meet my requirement. i need to observe network bandwidth used by only a specific process .
View 3 Replies View RelatedI first created a fork on github from an existing git repo. Then I made changes to my fork and pushed them to github again. After that the person from who I forked included my changes in his code but made some alterations on it. What I want to do know is having the exact code he has in the repo. This way I am sure that I actually develop on the same code.
I wonder how I should do this. I tried using git mergetool but I had some conflicts. So if I resolve the conflicts and make some mistake here, then I still wouldn't have the code the original repo(the repo where I forked from) has. what is the correct way to do this?
In playback application i guess "snd_pcm_lib_write1" is the function call used to write the audio data to sound card at kernel level.If that is true. how can i send the same audio data at kernel level to other system connected over LAN.
View 1 Replies View RelatedWhen someone is speaking into the mic, I'd like a "level meter" such as the one that comes with gnome sound recorder, that flashes up and down when a sound is made or somebody talks.This will be done in Javascript, using the brand new "Rainbow API", i.e. inside the browser.I know nothing about audio programming, so - where would I get *started* with something like this? Could anyone tell me at least WHAT to Google?
View 3 Replies View RelatedThe following C++ program doesn't catch the exception:
Code:
#include <iostream>
using namespace std;
[code]...
I'll just say I am a complete Linux beginner, but I have done vbs, js, php, html web type stuff so I'm not a complete beginner to programming.However I've been trying to learn C and python but it's not making a huge amount of sense.I am wanting to make a simple low level program that copies an image from a mjpeg stream on 192.168.0.1/videostream.cgi for example to a variable then save that variable to a file on my system.I am aware that there are programs out there that would do this but I still want to make my own.
View 1 Replies View RelatedI wrote a C++ program that uses two different parsers. The first parser is reading program arguments from command line:./mybin arg1 arg2 ...then during program execution there's an interactive prompt asking for more parameters:
...
>> (second bunch of arguments here)
...
I'd like to run my program inside a bash script, but I don't know how to give the second level arguments.
i was recently building on a simple socket program i had written in python basically like a little chat client but i added a server_socket.close command to kill the server on disconnect and now im getting all sorts of indentation errors
Code:
#! /usr/bin/python
2 import socket
3 server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
4 server_socket.bind(("localhost", 5000))
[code]....
IndentationError: unindent does not match any outer indentation level
The algorithm for reading and writing disk blocks use the algorithm getblk to allocate buffers from the pool. In the algorithm getblk, if the kernel removes a buffer from the free list, it must raise the processor priority level to block out interrupts before checking the free list. Why ?Where can i find the C implementation of the above algorithm for buffer allocation in the linux source code ?
View 1 Replies View Related