Programming :: Disable Irq Line From User Space?

Jul 14, 2011

I have written a device driver and I would like to disable an interrupt. In kernel space there is a function called "disable_irq(int irq)", but, is it possible to do it from user space?

View 7 Replies


ADVERTISEMENT

Programming :: Passing Data Between Kernel Space To User Space In Asynchronous Way

Dec 13, 2010

I am developing a I2C CDROM client driver. The CDROM firmware supports TOC information read through a I2C command. It sends the TOC information in burst ( Interrupts a GPIO pin when it is ready ) and my CPU does a I2C read to read the TOC. When the CDROM firmware finishes sending the last data burst , it informs my CPU that it is done with the TOC, by a flag in the last data burst. I would like to know, which is the most efficinet way I can send these TOC information to userspace?

View 4 Replies View Related

Programming :: Function In Kernel Space Called Form User Space

Jul 7, 2009

I wanna write a file in kernel space but from my searching I can to know that instead of writeing file in kernel space ,I can write data to user space by copy_to_user space.

But link is missing ...I dont know how will my user space will access kernel space means my function in kernel space which will do copy_to_user /....How my user space function will call my kernel level function ..

Can any one of you provide me with some example file which are doing this .I know every char driver is using it ...but i could not trace back how user level function is accessing it ...i m confused between user space and kernel space.

View 2 Replies View Related

Programming :: Call Socket Prog Code Written In User Space From Kernel Space?

Jul 14, 2009

How to use execv from kernel space to call a user space program writtenfor socket prog.

I tried to write code for socket in kernel but its not working.

Socket code in kernel is also needed.

View 2 Replies View Related

Programming :: Signal From Kernel Space To User Space?

Jul 21, 2011

I have the following requirement in my module. The driver gets some data from the external device. After getting 1MB of data it has to send it to the user space application. What is the best thing to implement for this in driver.? Is it ok to implement like, after getting data, the driver will send a signal to the user space application. Then the user space application sends an ioctl to read the data. Is there any alternate, that the driver directly sends the data without the user space application asks for it.?

View 4 Replies View Related

General :: Division Of Logical Memory Space In To User Space And Kernel Space

Jan 4, 2010

Logical Memory Space of 4GB is divided in to 3GB User Space and 1GB Kernel Space. Always. Correct?

1. How can we change it? (just changing value of PAGE_OFFSET is okay?)

2. If system have only 256MB of memory (embedded system) and suppose Kernel Modules eat away all the memory during boot. User space will be left will no memory. Is this case possible?

View 2 Replies View Related

Programming :: Issue Ioctls To A Usb Driver From User Space?

Sep 17, 2010

I am looking for a way to issue ioctls to a usb driver from user space. Upon googling, I found that usbfs provides a way to do that, anyhow I can't find sample code to try that out.

Note:
I have written a sample usb driver on the lines of 'Linux device drivers' book. Now I need to try ioctls with usb drivers.

View 2 Replies View Related

Programming :: Vmsplice And Splice Usage In User Space?

Jun 10, 2009

I'm using vmsplice & splice to send memory buffers through a TCP socket. I have two issues using these methods:

1) According to the documentation, when using vmsplice with the flag SPLICE_F_GIFT, you cannot modify the buffer you've "given" the kernel. Currently, each time I want to send a buffer, I have to allocate a page-aligned buffer (fill it with data) and send it using vmsplice- splice. When can I deallocate this buffer? Is it possible to modify this buffer after the buffer is sent through the socket?

2) The buffer should be page-aligned both in memory and in length, but most of the time the sent messages (to the TCP socket) - are smaller than a page size - is it possible to "clear" the pipe from the remaining buffer?

View 1 Replies View Related

Programming :: Make A (user Space )process Pre Emptive / In 2.6 Kernel?

Dec 10, 2008

I am writing a program which i dont want the kernel scheduler to preempt before certain time duration. I am using the system call sched_get_priority_max to set the maximum priority. However it is not producing results.

View 3 Replies View Related

Programming :: Simulate A Serial Protocol In User Space Program To Test Reception Algorithm?

Jul 28, 2010

I want to simulate a serial protocol in user space program to test reception algorithm. The protocol is similar to UART protocol but frame format is different. The duration of 1 bit is 114,46 us. In my main function I'm creating two threads. Tx for simulating transmitting data and Rx for reception data. For measure time I use create_timer() function and signals. Each thread has its own timer and signal handler. Tx timer uses SIGUSR1 and Rx timer uses SIGUSR2. Tx thread sets the global variable and Rx reads it.

The timers are set to sample with 114,46 us period. When they reach this value signal handler should set the flag. Flag is check in thread and some operation are made. When I set the timers period for longer time (100 ms) everything works fine but when I change it to default value (114,46 us) the Rx thread doesn't receive the proper data. I am wondering if the 114,46 timer period is possible to simulate in user space? Whether the time will give me the proper resolution ? Theoretically it should provide 1 ns resolution.

View 3 Replies View Related

Programming :: Take A Single Line Of Input From User In Shell Script?

Mar 10, 2011

How do i take a single line of input from the user in a shell script?

View 3 Replies View Related

Programming :: Perl - Way To Encrypt Command-line Input When User Enter A Password ?

Nov 4, 2010

I need user to input a password through command line in Windows cmd prompt. Is there a way to encrypt the input (such as put it into ......) when user is typing ?

View 2 Replies View Related

Programming :: Bash Shell Read User Argument From Command Line And Test It

Aug 29, 2010

Trying to create a small script that will read user's input, test if user entered some input and if not display some message or display a text using user's input.

The script is the following but i get an error saying "[: 6: =: argument expected"

View 12 Replies View Related

General :: Calling User Space Callback Function From Kernel Space?

Sep 22, 2009

I am writing device driver in which i have to call callback function from kernel space, which are saving my data. But the callback functions are in userspace. While accessing them i am getting segmentation fault.

View 1 Replies View Related

Programming :: Create A Simple Program With Will Continually Read Input From The User Until They Enter A Blank Line?

Apr 6, 2011

basically i have to create a simple program with will continually read input from the user until they enter a blank linei know how to read in certain input but not sure how to get it continually in a loop

View 2 Replies View Related

General :: Virtual Space Seen By Each New Process In User Space?

Jun 21, 2010

In a 32-bit system, max memory addressable is 4GB. Now Linux kernel does memory mapping division of 1GB for kernel address space and 3GB for user address space. That means 4GB of virtual address space is divided between kernel (1GB) and user (3GB).

Q1. All virtual mapping utilizes the available physical RAM without any division? I mean to say that if RAM is 512MB then a page in kernel space can lie any where RAM (leave aside old PCI dma accesses)? (How this fits to fact that kernel memory is non-pageble)

Q2. If a process is created in user space, it has visibility 4GB address space or 3GB address space?

View 2 Replies View Related

Programming :: Copy And Replacing Specific Line From File1 To File2 Line By Line

Mar 22, 2011

I have two files, file1.traj and file2.traj. Both these files contain identical data and the data are arranged in same format in them. The first line of both files is a comment.

At line 7843 of both files there is a cartesian coordinate X, Y and Z ( three digits ). And at line 15685 there is another three digits. The number of lines in between two cartesian coordinates are 7841. And there are few hundreds of thousands of lines in a file.

What I need to do is copy the X Y Z coordinate (three digits) from file1.traj at line 7843 and paste into file2.traj at the same line number as in file1.traj. The next line will be 15685 from file1.traj and replace at line 15685 at file2.traj. And I dont want other lines (data) in file2.traj get altered. This sequence shall be going on until the end of the file. Means copy and substitude the selected lines from file1.traj into file2.traj.

I tried to use paste command but I cant do for specified line alone.

Here i showed the data format in the file. I used the line number for clarity purpose.

Code:

View 10 Replies View Related

Programming :: Access A File Line By Line, And Check The Length Of Each Line.

Feb 13, 2011

I want to access a file, and check the length of every line.After, i want to check and replace all lines with length over 10 characters, with a message.Does anyone have a clue on that?

View 1 Replies View Related

Ubuntu :: Access User Account 1 Home Directory From User 2 Work Space?

Jun 16, 2011

Do you think there is a way of accessing different user data from another account which I have set up.

Ie. user 1 = account has messed up

user 2 = account works fine

access user account 1 home directory from user 2 work space?

View 9 Replies View Related

Programming :: Compare Two Files Line By Line And Print The Line Which Is Same?

May 30, 2011

I am trying to write a program in C which compares two files and prints the line that is equal.

Here file1.txt has

and file2.txt has

Note: file2.txt consist of only a single string where as file2.txt has multiple lines. Actually im comparing two files with md5sum values.

Here is the code but it compares only first line of files..but it should compare the whole file1..and sorry iam a beginner in C can any1 sujest some modification to this code so that..it can compare file2 with entire file1

Quote:

View 9 Replies View Related

Programming :: Insert Line Using Sed Or Awk At Line Using Line Number As Variable

Jul 25, 2011

I want to insert a line at a particular line number using sed or awk. where line number is not fixed and is in form of variable.

I want to use variable in sed or awk command.I tried something like below, but no luck.

View 7 Replies View Related

General :: Disable User And Change User Password Using SSH?

Oct 5, 2010

How do I disable and change the user password using SSH on a Linux

View 3 Replies View Related

General :: Measure Kernel Space Time And User Space Time?

Nov 28, 2010

measure kernel space time and user space time?

View 1 Replies View Related

OpenSUSE Hardware :: Cannot Disable NumLock Using IBM Space Saver

Feb 10, 2010

I have set the Space Saver as my keyboard layout in the KDE control center*, but Shift+NumLock/ScrollLock still does not work as it should to disable NumLock. I have tried both ibm_space_saver and ibm_spacesaver (isn't this practically a duplicate entry?) and restarted after each, to no avail.

Also, a second, possibly related problem -- why, at the login screen, does it take so long for my keyboard and mouse to start working? Maybe ten seconds after the login prompt seems to be ready -- only then can I actually do anything.



* I think this should be in Keyboard & Mouse instead of Regional & Language, but I can understand why it's there.

View 2 Replies View Related

Programming :: Create File Listing In C++ That Will Generate Line Number On Every Line Of Code

Apr 11, 2010

I have a project due for my Intro to C++ class and we are suppose to generate a file listing that will take an input of a C++ source code with .cpp extension and make a copy of it with a .lst extention that will have a line number preceding each and every line.

View 12 Replies View Related

Programming :: Set Indent In .emacs To Enable New Line Starts From The Same Position Of Previous Line?

Dec 29, 2010

How can I set indent in .emacs to enable my new line starts from the same position of previous line?

like this;

Hello world <enter>
Second Hello world // "S" starts right under first line's "H"

View 4 Replies View Related

Programming :: Adding Line From File1 Into A Line Of Another File Based On Maching IDs

Jan 3, 2011

I wish to add information to one of my files based on matching IDs,

Here is an example

(the id is the 3 colunm)

(the ID is the 2 colunm)

And the output i wish to be

OUTPUT:

So as you can see the ones that do not match are still present, and the ones that do match just have the extra information from file2.txt added to them.

I thought about using join but that only seems to join the ones that match displays thoes only. i would like all the information in the output file.

View 6 Replies View Related

Programming :: BASH: Each Line Of Multiple Text Files Gets Added To One Line?

Sep 12, 2010

I currently have 3 files with floating point data that I wish to have in a single file with the format:

Code:

F1 F1 F3 Output
a1 b1 c1 a1 b1 c1
a2 b2 c2 a2 b2 c2
a3 b3 c3 a3 b3 c3
a4 b4 c4 a4 b4 c4

View 3 Replies View Related

Programming :: Perl Script To Replace Line After Finding Previous Line

Feb 28, 2011

At the moment I have a flat file which is being used by a few people. I want a script to remotely change the file, so I can start logging who is doing what.At this point here is one requirement I am trying to develop. We have text blocks who pretty much look like.I hope this is somewhat clear. I try to find $param for the right $workflow and change that. Can you help me to find $$var3 and change that?

View 1 Replies View Related

Programming :: Programing - Reading File Line By Line Then Char By Char In Each Line

May 29, 2010

I've never programed shell scripting.

Code goes like so:

I simply want to read a file "data.txt" line by line Then char by char and add them into a result var. The file is supossed to always contain numeric values

View 8 Replies View Related







Copyrights 2005-15 www.BigResource.com, All rights reserved