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31
votes
3answers
2k views

Does the kernel have a main() function? [closed]

I am learning device drivers and Kernel programming. According to Jonathan Corbet's book, there is no main() function in device drivers. So I two questions: Why don't we need a main() function in ...
20
votes
1answer
446 views

How to get started writing drivers?

I have a throw-away cheap laptop I'd like to twiddle around, a Thinkpad SL 500. What bothers me are two leds, the one for wireless connectivity, and the one for hibernation, which don't light up at ...
19
votes
5answers
5k views

What is the difference between kernel drivers and kernel modules?

When I do a lspci -k on my Kubuntu with a 3.2.0-29-generic kernel I can see something like this: 01:00.0 VGA compatible controller: NVIDIA Corporation G86 [Quadro NVS 290] (rev a1) Subsystem: ...
13
votes
1answer
3k views

What is difference between User space and Kernel space?

Is Kernel space used when Kernel is executing on the behalf of the user program i.e. System Call? Or is it the address space for all the Kernel threads (for example scheduler)? If it is the first ...
11
votes
1answer
9k views

How to use Linux kernel driver bind/unbind interface for USB-HID devices?

First background. I am developing a driver for Logitech game-panel devices. It's a keyboard with a screen on it. The driver is working nicely but by default the device is handled by HID. In order to ...
7
votes
3answers
7k views

mptscsih: ioc0: task abort: SUCCESS (rv=2002) causes 30 seconds freezing

I/O to my software RAID6 often freezes for around 30 seconds after which everything is back to normal. After the freeze is over this is put into syslog: Mar 14 18:43:57 server kernel: [35649.816060] ...
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 ...
4
votes
3answers
119 views

How does libusb access kernel stuff?

From what I understand: Generally speaking, a driver runs in kernel space and can be called from user space. Only code in kernel space can call usb low level things / ioctl libusb is a library, so ...
4
votes
2answers
66 views

Why do some drivers still require firmware?

There are a ton of reverse-engineered drivers in the Linux kernel tree. Yet some drivers, especially wireless drivers, require firmware binary blobs to run properly. What prevents someone from ...
4
votes
1answer
1k views

Configure Wacom Intuos Graphics Pad in Linux Mint 15

I purchased a Wacom Intuos graphics pad recently (specifically, Create Pen & Touch Tablet, which I think is the rebranding of the Intuos 4), and I am trying to configure it on my Linux Mint 15 ...
3
votes
2answers
7k views

How to create .ko files in Linux

I have written one driver for one device in Linux. How can I create (using gcc) a .ko file so that I can insert it into the kernel?
3
votes
2answers
3k views

Ubuntu make fails with No such file or directory /lib/modules/3.4.0/build

I am trying to build the CP210x driver for the 3.x.x kernel on ChrUbuntu. Build instructions: Ubuntu: make ( your cp210x driver ) cp cp210x.ko ...
3
votes
1answer
259 views

Chrooted drivers

If the host has the kernel drivers properly loaded, would the chrooted enviroment be able to use them (ex. wireless, power)? Does the chrooted enviroment need its Xorg drivers to be configured or ...
3
votes
1answer
99 views

sources for doing profiling of kernel portions?

Related to my previous post. I did not find any specific driver for which I can do profiling and benchmarking. However there is a one driver jffs2 filesystem for flash devices but I didn't know about ...
3
votes
1answer
3k views

USB to Serial in Chrubuntu - /dev/ttyUSB0 missing

The usbserial stuff has been working so well for me in Ubuntu for a number of years that I have almost forgotten how to troubleshoot it. I just installed Chrubuntu, however, and now my usbserial is ...
3
votes
0answers
232 views

Debian driver needed for Intel ICH7M SouthBridge I/O controller

I am using a motherboard based on this architecture. http://www.intel.com/content/www/us/en/intelligent-systems/navy-pier/embedded-intel-atom-n270-with-mobile-intel-945gse-express-chipset.html I ...
3
votes
0answers
155 views

Enabling GPIO in kernel not working

I have tried to enable the GPIO pins for my system through the Kernel but I am not able to get them to work. When I try this: echo 1 > /sys/class/gpio/export The terminal window just closes. ...
3
votes
1answer
229 views

How can I prevent drivers from binding USB devices on a certain bus?

I have a setup with two Logitech Unifying receivers, each receiver has a keyboard bound to it. One of the receiver is to be used by the physical machine to which the devices are connected, the other ...
2
votes
2answers
47 views

Where do sound drivers live? [closed]

A little while ago I searched for a good driver for my sound card (with surround sound support) and didn't find any. So it seems there is none. I thought I could try (even though I think nothing ...
2
votes
1answer
2k views

How to install much newer mpt2sas driver version in debian squeeze?

Linux debian squeeze 6.0.6 (2.6.32-5-amd64) is supplied with quite an old 02.100.03.00 version of the mpt2sas driver. I do wish to install a much newer mpt2sas driver version. In know there are ...
2
votes
1answer
8k views

Xorg -configure doesn't work with nouveau drivers

I'm having problems setting up X.org on Gentoo. At the moment I have kernel 2.6.37-gentoo-r4 installed and have built X against this kernel. I have nouveau drivers installed and they seem to be ...
2
votes
2answers
104 views

Kernel module parameters vs /sys/class/… explanation

I was making (my first) kernel module to play with the gpio pins of my pandaboard and interrupts. Already "built-in", I noticed you can do (briefly) cd /sys/class/gpio echo 138 > export # a file ...
2
votes
2answers
500 views

Linux I/O shared memory access

I'm pretty confused on how linux manages I/O shared memory to communicate with devices that use it. If I understood it correctly linux kernel starts mapped at 0x100000 (to avoid the first megabyte ...
2
votes
1answer
894 views

Atheros ar8151 driver for kernel 3.x (fedora 16)

Yesterday, I installed Fedora 16 and found no wireless connection available. Then I found the ar81family driver But it seems like it does not work with kernel 3. I changed the makefile to ignore ...
2
votes
0answers
25 views

Opening a device node in a device driver in linux [migrated]

I am writing a device driver on Xillinux that will read and write data to an FPGA application over Xillybus. Basically I want to create device nodes such as /dev/pe1, and when I write to the nodes ...
2
votes
1answer
164 views

RTL8180 kernel module freezing with Realtek RTL8185L chipset

I've recently purchased a PEAK wireless PCI board. I needed a card with removable antenna capability to test a high gain antenna that I had laying around. Went to my local hardware store and I got ...
2
votes
0answers
259 views

A problem with mknod when logged in as root

I am trying to load a char device driver written by myself. To achieve this I use a modified bash script published on this site: http://www.makelinux.net/ldd3/chp-3-sect-2. Here is my version of the ...
2
votes
1answer
304 views

Upgrading I2C client drivers to the newer binding model

I am trying to port some I2C device drivers I wrote for an other kernel to work with the newer I2C binding model. The kernel documentation goes through the steps of doing this: ...
1
vote
3answers
56 views

How to create a kernel source tree?

I am reading a book on creating drivers on Linux, I do not have too much experience with Linux, I have installed a quite a few distros before but I have always used windows as my main operating ...
1
vote
2answers
186 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
vote
1answer
32 views

Why have a fake LR-WPAN driver?

In the Linux kernel configuration, a fake LR-WPAN driver can be enabled and added to the kernel that will be compiled. Why would someone want a fake LR-WPAN driver? I assume it would be for debugging, ...
1
vote
1answer
2k views

I need a step by step guide to build kernel modules in ChrUbuntu

I don't have experience building kernel modules. And worse, I'm trying to do it on ChrUbuntu, so it seems that I cannot follow the existing Ubuntu guides. For example, this command fails: # apt-get ...
1
vote
1answer
38 views

Linux Kernel Firewire Feature: Use Unclear

In the Linux kernel, there is a setting "FireWire SBP-2 fabric module". I do not understand the documentation: Say Y or M here to enable SCSI target functionality over FireWire. This enables you ...
1
vote
3answers
339 views

How compatible is Centos in respect to hardware for desktop systems?

I have been tasked with creating a promotional/sales tool for our clients and sales people . (about 8400 users) It is expected that the tool will be used on office and home systems. The tool will ...
1
vote
2answers
1k views

Finding Linux distribution with proper hardware driver support

To me it is a jungle to find what Linux distribution to choose... Of course one would like to use as much performance as possible from the machine. In my case I have a HP Pavilion dv6-6008eo - in ...
1
vote
1answer
41 views

Attaching two network cards two different drivers

I have an Ubuntu 12.04 server that has two 10 Gb ethernet cards that are using the ixgbe driver. I'm installing the PF_RING DNA drivers for these cards (what that is isn't important). I want interface ...
1
vote
1answer
113 views

Difference between Device file and device drivers

I am beginner in device driver programming. I don't get the difference between device drivers and device files in Linux. Can anyone explain the difference?
1
vote
1answer
123 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 ...
1
vote
2answers
342 views

Where to find source code of Linux NTFS driver?

Brief description : Linux driver gives us a chance to interface with an NTFS filesystem. Thanks to this driver, we can use built-in Linux commands on an NTFS filesystem. Ex : ls, chown, chmod, cd, ...
1
vote
1answer
44 views

System Halt on REBOOT, Shutdown & Restarts as expected

Recently went from Centos 6.4 to Centos 6.5. System is Dell T410 Tower. Whenever I reboot, system runs through post, passes IPv4 Settings, then announces: PCIe Training Error: Slot 1 system halted ...
1
vote
1answer
52 views

Problem installing input-wacom-0.20.0

I run Linux Mint 14. I bought a wacom intuos pen&touch small tablet and my old driver (don't know which one, someone installed it for me...) does not support it. I did a little research and found ...
1
vote
0answers
56 views

Writing a USB driver from scratch [closed]

I have an FPGA that I'm going to be connecting to a Raspberry Pi running Raspbian 3.6.11+. I've been reading up on how to write a USB2.0 HS driver for linux and how to reverse engineer USB ...
1
vote
1answer
311 views

Virtualbox kernel modules not loading at boot - ubuntu 12.04

I have been running virtualbox on a ubuntu 12.04 laptop for a while and it has all worked smooth, but suddenly, probably after a kernel upgrade, the vbox* modules are not loading at boot, if I ...
1
vote
0answers
147 views

Archbang can't connect to wireless

Last week I tried Crunchbang 11, it couldn't connect to wireless. Yesterday I removed it and installed Archbang from CD (final 2012 version). Everything was working perfectly, when I did pacman -Syu ...
1
vote
1answer
87 views

What happen when we plug a device in to computer

I'm currently learning about device developement for linux, I have glaced at some books such as LLD3, .. but I still can't understand what happen when we plug a device into computer, That's my ...
1
vote
0answers
175 views

Changing default line discipline at kernel level [closed]

How to assign line discipline to particular serial port at kernel level?
0
votes
1answer
38 views

Downgrade USB 3.0 to USB 2.0 in ubuntu

I have USB 2.0 device when I plugged this device into the USB 3.0 port of my system then system gets hanged, after researching many of the solutions says that you can downgrade USB 3.0 to USB 2.0. But ...
0
votes
2answers
198 views

Install Fedora core 15 on HP Smart Array Controller HDD

I need to install "Fedora Core 15" Linux on to HP Smart Array Controller attached HDD. Problem is Fedora Core 15 kernel do not has HPSA device driver. I tried to load (my own build) HPSA driver ...
0
votes
2answers
19 views

GPIO User Space App

GPIO User Space App describes user space application to test the GPIO. Another related link is Linux GPIO Driver. This would be running on a xilinx zynq board having an ARM Cortex A 9 processor. I ...
0
votes
1answer
32 views

Recommend Course of Action? [closed]

I have an Asus VivoBook that came with windows installed on it. For amusement and profit, I have been hacking away trying to to serve a website from behind a wireless router at my house. At some ...