What are the prerequisite for compiling Linux on Cygwin?
Is it similar to compiling on a Linux PC, or do we need to add patches?
Is it similar to compiling on a Linux PC, or do we need to add patches?
I think de facto, it should be the same with mainline kernels.
The point is that you probably don't want an unmodified kernel, otherwise you wouldn't be asking how to build one. So the question is a lot more complex: Will the Linux kernel, including everything you include which might not be maintained upstream, compile successfully under Cygwin?
There's no telling that, and frankly, I don't even think it matters.
Virtualization is a relatively mature technology nowadays. Get yourself a Linux VM (there's many ready-made build systems out there), get yourself a matching virtualizer (VirtualBox will totally do), and build your kernel on a running Linux. Virtualization nowadays is the answer to these kind of questions, IMHO, because it was meant to give you the right OS for the particular job you want to do.
Compiling the Linux kernel (that's the job) nowadays is best done on a Linux system (that's the right OS for it), period.
Related
I'm working on a side project which requires me to configure and compile a tiny Linux System based on Ubuntu.
The result should be a tiny OS with the following features:
A Bootloader
A Kernel
A Process
A Thread
Miscellaneous (if possible)
A File System
Virtual memory
A Console
I read lots of documents about it, one of them being: http://users.cecs.anu.edu.au/~okeefe/p2b/buildMin/buildMin.html#toc3
I deleted the file system, and recompiled the kernel using make xconfig. I tried to deactivate modules and configurations many times, but it's not working for me.
How can I configure the kernel for the OS with only the features I listed above? What options can I disable or enable while still having a working system?
Having the Kernel very small is not important for Ubuntu, so maybe choosing Ubuntu is part of your problem. I would use as starting point what OpenWRT does. They do a good work making the Kernel small and it is easy to get started. OpenWrt Buildroot – Usage
try Linux From Scratch. It is a step by step approach on building a minimal Linux system from which you can evolve later on. http://www.linuxfromscratch.org/.
Use Gentoo Linux distribution - it's great for practicing on creation of Linux systems. Gentoo has excellent setup documentation, for example about configuring the kernel.
And Gentoo is a little easier and faster to setup than Linux From Scratch (LFS). If you want to go deeper, then LFS may be a good learning step too.
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!
I want to build a sample program and as an initial step to learn KVM I started it from the link below.
http://www.linuxjournal.com/magazine/linux-kvm-learning-tool?page=0,1
I see that this is quite an old post for KVM, but I realize that the very first program does not compiles as it asks to include libkvm.h, which is not in my Ubuntu 13.04 installation.
To prepare for this program I installed qemu-kvm,dkms and libvirt stuff.
I also verified that the user has kvm and libvirtd in the group.
I am running Ubuntu on virtual-box on a modern i7 processor windows host.
So I have two different questions here -
1) Since I dont find libkvm.h in my box, what is the way compile my program and learn this kind of programming. If you have any tutorials please forward.
2) I got know that there is another libkvm that is used in BSD style Unix (e.g NetBSD/FreeBSD) that is used to access kernel data-strucrtures. From internet I see that GDB uses that library to fetch info from kernel memory. KVM in linux is a tool to create virtual machines on a Linux box. Is my understanding correct or is there anything more to it? Please provide a comparative analysis between these two libraries, namely libkvm on linux and libkvm on BSD?
As you already said, Linux KVM is a virtualisation technique whereas BSD kvm is much older, the acronym even expands to something different, and is a library to access (not only) kernel data structures in a defined manner.
They are totally separate and different things that have absolutely nothing to do with each other except for sharing the same acronym.
As do, for example, Keyboard-Video-Mouse switches. I was confused by all those Linux people talking about a “KVM” thing suddenly, back when Linux-KVM first came out, and not meaning those.
I spent the last three weeks researching about crossdevelopment under Mac OS X. I want to achieve two separate results, but I believe they can be reached through the same path.
I want to
set up distcc to help my old Gentoo laptop using the iMac I recently got at home (OS X 10.6, 64 bit native) which I also use for iOS development, so Xcode 4 tools are already there;
develop my pet project which is an elf kernel for x86, x86_64, and arm (and I'll stop here as it's OT).
So, after a lot of that thinking thing we all do in these cases, I came up the idea that to reach the first goal I need to set up an i686-pc-linux-gnu toolchain (or is it i686-unknown-linux-gnu?) with all the appropriate versions (eg gcc-4.4) and make it callable by distcc. It seems like a reasonable task, but unfortunately there seem to be clearer tools and instructions to build toolchains for obscure archs like sparc or mips, and not a single reasonably updated resource on how to go for x86 the best way. Therefore, first question: is there anybody that succesfully build such a toolchain and feels like sharing the pain? :)
Second goal. My current workbench is made of Gentoo on an i686 laptop (yes, the same as the first goal) with all the regular development stuff, and I use QEMU to test it (its gdb integration is awesome). What I'd really like to do is to keep using the laptop while travelling (I do a lot of commuting) and continue to work and test on the iMac when I'm home (git is awesome in this respect). Hence, second question: is there anybody that have done something like this and wants to share?
I'd really appreciate any input. Seriously.
EDIT I know about MacPorts, crosstool, and crosstool-ng. I tried installing i386-elf-binutils 2.18 from MacPorts just to discover I have 2.20 in my laptop. Also I couldn't get gcc44 to produce i686-pc-linux-gnu elf objects, and using i386-elf-gcc is not an option as I need 4.4 and the packaged one is 4.3.
This is no easy task, specially because you want to cross compile for so many different platforms.
The most used approach is to run a Virtual Machine with the desired OS (e.g. VirtualBox, Parallels, VMWare Fusion) and install your workbench tools to work from it. This is very often used because it's not complex to setup and it also make it easier to write, test and debug code for/from the target system.
Of course, if you search enough you'll find all sorts of hacks/tricks to setup a toolchain on Mac OS X and compile code for other architectures:
One of these uses Buildroot, but that means that there is no official support for Mac OS X.
Another one, also interesting, offers a .dmg package with the tools needed to compile for Linux on MacOS X.
You already mentioned Gentoo, so I think you should take a look at Gentoo Prefix. Gentoo Prefix lets you install a small Gentoo system in a user defined directory (= prefix). From there, you may start a shell which lets you use portage (= Gentoo's package system) which should enable you to install the necessary tools.
I do not know in what shape Prefix on OS X today is, but I was able to install it on a friend's MacBook a year or so ago. If you are interested, I can give further details about the installation process which can be a bit tricky.
In my Operating Systems class we are looking to modify a Linux kernel with some simple system calls of our own in C.
What would be a good distro suited for this purpose? We don't need any frills, no GUI, a vanilla kernel, etc. The more basic the better.
I was able to modify the kernel pretty easily using a minimal Gentoo install.
Just install gentoo, follow the installation instructions, then:
$ emerge gentoo-sources
$ emerge emacs
$ cd /usr/src/linux
In my operating systems course last semester we used User Mode Linux, the big advantage being that when you hose the system, you can simply kill the process with no risk to the host environment.
Adding/Modifying system calls is tedious but trivial regardless of the kernel you use. However the 2.6 kernel is significantly more massive and complex, so if you're going to be modifying the code in a significant way the older kernels are easier to work with and much better documented. (ie: easier to find books and references)
Happy hacking :)
archlinux++
but really.. gentoo, slack, and arch are all more-or-less good choices
Arch Linux provides a great platform for kernel development that is also very functional. If you learn to use pacman, it will actually make testing your kernel modifications quite easily and provides the sources and tools in a sane manner.
I do think that if you are serious about learning linux and kernel hacking, doing a Linux From Scratch install should be on your list. It's a great distro/book and will let you build the platform for development yourself.
On all distributions, you can install the vanilla kernel.org sources instead of the distribution-related kernel packages, which is probably a good idea anyway when you want to do kernel development.
However, you'll be in trouble when you want to use any recent distribution with non-2.6 kernels, because they often build libc6 in a way that it cannot run with 2.4. Additionally, a lot of the guts of hardware management (like udev) require fairly recent kernels.
Apart from that, using Debian gives you a barebone system, and installing your own kernels is a breeze with kernel-package.
I wouldn't necessarily say any particular distro is geared towards kernel development as such, but if you want a traditional Linux distro that doesn't pile too much custom configuration stuff between you and the kernel, Slackware is a decent choice.
My suggestion is to grab the latest kernel. There will be more debugging features inside it than in an older kernel. Also, older kernels would pretty much look just as complex as the most recent to the newbie.
As for the distribution itself, you can't really go wrong. If all you want is to try some custom system calls, then grab whatever mainstream distribution which gives you a nice development environment. Then compile and try your customized glibc without installing it over the distro's.
When choosing a distro for kernel development, remember that it's the kernel you want to hack, not the distro itself. You will therefor want an easy distro that stays out of your way as much as possible. Ubuntu says out of the way fairly nicely.
IANAKH
A non-linux alternative is Geek OS, but this is very much aimed at the educational level, and is not a practical kernel. It is ultra-simple though.
well I have found one called "minix" it isn't really a linux distro, but it was made specifically for teaching, but if you can only use a linux distro, then it shouldn't matter, I am pretty sure all distros have the same kernel
Gentoo if you dont mind automated compilation (most people think that gentoo is Linux From Scratch => you have to do everything on your own).
Arch if you have slower computer (laptop).
Biggest advantage of these two is that they have very very good documentation and only installing Gentoo f.e. gives you basic knowledge about init system and what services has to run. If one copy&paste commands from guide it's worthless though (luckily handbook makes people think a bit, thus preventing kids from installing gentoo and taking over our neat #irc) :D