I am new to linux programming & interested to tweak linux kernel(though I am not sure, what to tweak, I am planning to write drivers for particular device). To learn internal of kernel, I have started from historic kernel release (first release).
My problem is, how to test whatever changes I am doing for development, without disturbing my current os environment.(ubuntu 12, 64 bit). Is there any way like virtual box, sandbox?
Along with these, if anybody send some good approaches to learn these things, I would be really greatful.
Thank You.
If you're new to linux programming then you really don't want to be tweaking the kernel. You really want to be an advanced programmer capable of programming drivers and complex software first.
But yes there is, you can can create a virtual machine using openbox or vmware. If you're really keen on tweaking the kernel you probably want to first just try compiling and configuring the kernel and seeing if that works.
Also make sure you're well acquainted with how the kernel works and advanced OS designs in general.
Search in google fr "Kernel configuration" you u will get many links how to configure your own kernel.
And one more thing do not use a outdated version of kernel ,always use latest stable release , because a lot of code and API is changed in new versions and no book in market is updated so ,, u have to read from kernel documentation. Thats the best way to learn the most updated information about linux kernel
Yes, you can test your changes on any of the commonly available virtual machines (VMs); that way, whatever changes you make to the VM kernel won't affect native OS.
Personally, I prefer using CentOS 64 bit on VMWare Player. With this setup, I got away with minimal system maintenance while was able to focus on the actual job at hand. Once the VM is up & running, you can download and compile one of the latest stable releases from kernel.org. Instructions on compiling your downloaded version of kernel could be found here and here; however, this may require little tweaking based on your actual setup. Once the VM is running on your desired version of kernel, using a combination of cscope and ctags will help you immensely in kernel code browsing.
Finally, if you want to become a serious kernel programmer and write your own device drivers, you need to get familiar with it in the first place. Below are a few excellent references -
Linux Device Driver by Corbet, Rubini, Kroah-Hartman, 3rd edition
Linux Kernel Development by Robert Love, 3rd edition
Understanding the Linux Kernel by Bovet, Cesati
Linux kernel source (ideally placed into your /usr/src/$(DESIRED_KERNEL) path, symlinked to /usr/src/linux)
Going through these books is a tedious job and chances are that you may hit the roadblock from time to time. kernelnewbies mailing list and StackOverflow are some of the few reliable places where people would be happy to answer to your queries.
Good luck!
How can I port an application based on OS X to Linux? It is closed source and working in Windows either. It is not wrriten in Objective C and doesn't use Cocoa.
Thank you.
If you saying that application working in Windows, so the easiest way is to use Wine to get start it on Linux.
I don't think it being closed source has any effect on porting it to Linux - it's the same anyway.
Just find alternatives to any win32-specific libraries or use a compatibility layer as necessary. Your team may however need to think very carefully about which distros they choose to support.
There is no easy path if you don't gave the source code as there are few Mac emulators. You might have some luck get OSX to run under a VM but Apple frowns upon that.
In the end it sounds like a ground up rebuild.
I will have (maybe) to work soon on ARM platform hosting a linux distribution (I don't know which distribution ..).
I know the project concerns video streaming, but I can't tell you more. Actually I only received the announe, and meet nobody yet.
I've never worked on such platform. So the idea for me is to test before the project starts.
What would you advise me to undestand how works such platform ? Internet links? Tutorials? Tools
Morevover, as I don't have any ARM processor at home (well only my iPhone ..) Which virtual machine would you advise me? (I clearly don't want to lose time installing and testing every one of them.)
I am aware of this page on wikipedia. Which one is the more appropriate running on a MacOS X 10.5/intel platform? Which linux distribution to install on the virtual machine?
I know the topic is quite wide, so any idea is welcomed! :-)
For a virtual machine that can emulate a ARM platform try QEMU. You can install a ARM-based Debian Linux distribution and tinker around with it. A google search on ARM, QEMU and Debian will get you started.
Also: Don't worry to much about the ARM CPU. You will use linux, so all the low-level stuff is already done for you. It's much more important to learn how the linux boot process works. How to install stuff ect. You will rarely (if ever) notice that you're running on a ARM device. The big difference to a PC running linux is, that the ARM will be a lot slower.
If you're looking for a real piece of hardware to play around with I suggest that you take a look at the beagleboard (www.beagleboard.org). It's cheap (around $150) and runs (among other things) various linux distributions.
With the beagleboard you'll get the whole linux cross compilation experience if you want (be warned: you'll pull your hair out).
I can't answer all of your questions, but there's a full port of Debian GNU/Linux on ARM. Works fabulously in my experience (I've tried it on a QNAP). Everything that's available in Debian works on QNAP now! So it's probably easiest to first try Debian tools and packages that come close to your project, and then continue from there.
As I come up with linux ,I found the commands are different in OpenSuse and Ubuntu.
Which of them is suitable to somebody who was new in linux and want to master the command
needed when programming and using linux?
I got the impression that OpenSuSE did some things a little unconventionally (kdesu, gksu), but it's a fine (KDE) distro. I've found (K)Ubuntu is a little better for beginners since it has access to huge compiled package repositories, plus the community is unbeatable.
They're pretty similar for most things, including programming.
Whichever one the people around you can ask questions of know. The value of a knowledgeable support network vastly outweigh the benefits of a particular distribution. If you don't have a local support network, I'd go with Ubuntu, they tend to have more useful resources on the 'net (and it's the distro I'd prefer out of those two options).
Any of Ubuntu/Slackware/Gentoo should be fine as a development environment. You didn't mention what kind of programming you're interested in, and that may have some influence on the answer, too.
If you are at all interested in making better code I also recommend dual booting (or running a 2nd computer) into a non-Linux system such as OpenBSD/FreeBSD, OpenSolaris, etc. Writing code that's portable across UNIX systems isn't just a good idea for portability's sake, it can also help shake out some bugs. The same can be said for working with 32-bit vs. 64-bit, big endian vs. little endian platforms. You can pick up an old 64-bit Sun workstation for cheap and use it to test your code.
We'd have to know your preferences better to be able to answer that. Basically any LINUX would do i guess. I heard nice feedback from Ubuntu, though.
I'm running on Ubuntu right now. It was easier than windows to get running. Very smooth. Of course, advanced functions are beyond me right now. With C# classes and everything else I gave up on trying to learn too much and just run it as is. It has a very good user interface, and I've heard a new version is out or coming out as well, probably more eye candy.
Check out Ubuntu. Doing a dual boot can't hurt since then you can try it out! You can also run some distributions straight off the disc to try them out.... Can't hurt to try it when it is free. Much more stable for me than XP, and faster. I HOPE Windows 7 ends up being less of a monster! I'd stick with Ubuntu if it was more compatible with windows programs. .NET development while in school typically isn't done on a Linux distribution!
best wishes, try it out!
I prefer Ubuntu. my 2 cents...
They are tools. Use the one that you are most comfortable with. Really calling them tools isn't a good analogy. Better is to call them vehicles. Use the vehicle that fits your needs and desires.
Actually , as a programmer you would face such questions everyday. Which framework? which language? which data structure ? ... you get the idea. There is no right answer.
Choose any. They are not too different. Soon you would not be a "new learner" and then it wouldn't matter anyway.
Depending on how deeply you want to learn, one possible candidate distro would be Linux From Scratch. It also has awesome documentation and by playing with it will surely make you think more "Linux"-way.
This is a very hard question; most distros aim to be "the best", or at least "good enough" for a wide variety of activities, of course including programming.
It's also an issue that easily spawn "wars", where people fight to claim that the distribution they use is the best, and that all others should conform. Heh.
My current preference is for Gentoo, and I think one (probably minor) advantage it has when programming is that since it is a source-based distribution, you typically never need to bother to get the "development version" of packages. If you have e.g. readline installed, you will have its header file(s) too, and so on. Many other distros split packages into "user" and "developer" versions, so you need to install both packages.
Of course, I guess in those cases the developer packages depend on the non-developer versions anyway, so if you always install developer versions, you'd be all set. Oh well. Nevermind, then. :)
When choosing a linux distro I usually consider two things:
1: packaging system (and release cycle):
Opensuse probably has the most up to date packages of any distro (without building your own), Ubuntu's packaging system tends to hold your hand a little bit more though. I have used both and found that as a developer I slightly preferred Opensuse since it was easier to get the latest versions of development packages (for example, IDEs).
2: default configuration/ease of administration:
All linux distros have their quirks here. Both Opensuse and Ubuntu are well documented and have good support forums. Opensuse has Yast which is a nice one stop shop for most configuration tasks. Ubuntu seems to be slightly better at automatically configuring itself. Really, either distro is fine here.
The good news is that there is not a wrong decision per se. I have used a lot (more than 10) linux distributions and I now stick to Opensuse. Ubuntu was a close second, the only reason that I don't use it is that I found I was often stuck waiting for its 6 month release cycle to get up to date dev packages (building the monodevelop beta was not feasible at the time). Opensuse's build service and the Packman third party repository seem to keep nearly current packages for everything I've ever wanted.
I use Gentoo and Ubuntu for development.
Gentoo I love because I can so easily select which packages I have available and which versions. The guy that did Flash 9 and 10 does his development on a Gentoo system as well.
Ubuntu I enjoy now because it's so stable. After a few years, a Gentoo installation will tend toward some instabilities that require sometimes rebuilding the whole installation.
Another I'd look at is Slackware.
The principles are mostly the same over the different distributions, so I'd suggest you to choose one and dig in. However, there are some considerations to make. If you want to program gui programs you need to make a decision about which graphic toolkit library to use (Qt, Gtk+ ...), which would also imply the choice of your desktop environment (GNOME, KDE, XFCE). As you will notice, in Linux world everything (or almost everything) depends on something else. I'm talking about the packages. It is quite common to reuse available libraries and not write your own so the decisions you would probably have to make are about which libraries/frameworks to use and which language.
I, however, chose Ubuntu and don't feel sorry at all.
It depends on what you want to do. If you want something easy to setup and basically just works, use Ubuntu. If you want to /learn/ Linux, I would recommend Slackware. Getting Slackware up and running will force you to know HOW and WHAT is going on with your installation. This can be good or bad, depending on your desires.
Ubuntu fits the build and the community is very helpful.
If your exploring Linux / GNU as a programmer, you might consider selecting a distribution that uses the apt packaging tool.
You will likely need to install lots of libraries with development headers and obtain the source code to other things. Apt makes it quite simple to do such things, it is very good at resolving package dependencies and fetching source packages.
Distributions using apt (either with .deb or .rpm packages) are Debian, Ubuntu (and its forks) and others.
That being said, Ubuntu does a really good job at keeping up to date with recent libraries and tools, while resisting the urge to cherry pick alpha / unstable code. My desktop is my development machine, I use Ubuntu.
I would vote for Ubuntu. The principles are the same while some of the "commands" are different. I assume you mean differences such as "sudo".
I'm very happy with my Ubuntu Server which handles all my development Windows VMs. I even used Ubuntu desktop on my laptop for a time...at least until I needed Visual Studio on it again. :-)
EDIT - "sudo" does exist in OpenSUSE
Gentoo is the easiest to use. I'd go with that
Hopefully this still falls within StackOverflow's umbrella!
I'm looking to create a quick boot linux laptop for my wife. All it really needs is to be able to do is browse the internet (with flash and video etc.).
Are there any distros that are made for this, or any guides out there that show good ways to speed stuff up? I've read that I should "remove stuff from the kernel that I don't use" but that's a little out of my skill set.
Thanks!
If you're using Ubuntu (or a variant, like xubuntu or kubuntu), there is a package called BootUp-Manager. There's an article about it over at Lifehacker. It lets you check and uncheck things in the startup and shutdown scripts to optimize things (such as turning off checking for new hardware, or whatever)
You may also be able to gain a simple speed-up by going into System->Administration->Services and disabling any services you don't need.
If you'd like to see how much time is being spent on each part, install the package Bootchart, and that should give you a detailed profile of everything that goes on during startup, and let you focus on the most time-consuming parts, and measure your progress as you tune the system.
I believe Xubuntu is designed for low memory footprint/fast booting and whatnot while still having a decent amount of features. Not a Linux user but it just seems to stick out in my head.
Some guys got an EEE PC netbook booting in 5 seconds running a modified version of Fedora. Might be a good starting point: http://lwn.net/Articles/299483/
Try: Damn Small Linux is a very versatile 50MB mini desktop oriented Linux distribution.
Alternatively, get an Asus motherboard with expressgate - it has an onboard Linux (spashtop) that boots in 3 seconds. Its designed for quick web surfing, IM, music etc whilst still letting you boot into your main OS.
If you really want it to boot fast, I would suggest creating an initrd containing exactly the software you need to do what you want it to do. The initrd will get read from the disk once as one large file, and then everything will run out of ram.
This is not an easy solution, the easiest solution will be jishi's solution of using a Live CD, but, that won't be the fastest solution.
I have been using Kubuntu 14.04.4/5 on a Dell laptop with dual boot. Am not real happy at the moment with it. You are all correct about the slowness of a liveCD.
There are LiveCD-versions of working linux-distros with browser and installed flash, java.
Check out LiveCD
http://en.wikipedia.org/wiki/Live_CD
you will find links to different flavours with download.
There are also USB-drive-versions.