I'm trying to run Linux in a VM so I can make changes and test them quickly. I came upon this tutorial...
http://blog.vmsplice.net/2011/02/near-instant-kernel-development-cycle.html
I tried the following command (in the linux-2.6 directory, checked out via git)...
kvm -kernel arch/x86/boot/bzImage -initrd /boot/initrd.img-2.6.38-10-generic -append "console=ttyS0" -nographic
I created the initrd.img-2.6.38-10-generic with the update-initramfs tool. Here is the output when I run that...
http://pastebin.com/HxGMMHSt
Failing to load some modules and not mounting anything. I think I'm missing some crucial step, I'm pretty unfamiliar with virtualization.
Running Ubuntu 11.04
Any help is appreciated, thanks.
Seems you did not installed the modules and kvm can not find them in /lib/modules. make modules_install may help.
Related
I have a CentOS Linux release 7.2.1511 (Core).
I want to build some kernel code for currently running kernel.
My uname -r says 3.10.0-327.10.1.el7.x86_64, but ls -l /usr/src/kernels/
shows only 3.10.0-327.13.1.el7.x86_64. Why do I have sources of not current kernel on my filesystem(vanilla fresh provisioned Digitalocean box)?
Why does yum install kernel-devel does not install headers for currently running kernel?
uname is a system call to the kernel to get information. It's telling you what's running on that machine. What's physically present on the hard drive can be anything that anyone has installed. Someone may have downloaded the wrong package or you may have multiple kernels installed etc. But, the one that's running is what uname is telling you.
I tried to create a vm for raspbian in ubuntu. I made a few changes in the raspbian to test if it works in other machines or not. After that i copied the edited image into my computer. Now i try to boot it with qemu but each time qemu opens, i can't see the raspbian. Here is my work
qemu-system-arm -kernel /usr/share/qemu_vms/kernel-qemu -cpu arm1176 -m 256 -M versatilepb -serial stdio -append "root=/dev/sda2 panic=1 rootfstype=ext4 rw" -hda /usr/share/raspi-image.img
So my kernel image is in the /usr/share/qemu_vms and my image is in /usr/share.
I tried to increase the ram amount but in that case even qemu didn't start up. Also i was following this tutorial(which is almost the same with other tutorials and my /etc/ld.so.preload is missing(i can't edit it at all).
I deleted -no-reboot option so it is in a loop for rebooting everytime but it seems that it can't find the image to start.
Any help would be very appreciated.
Sorry to add another thing but i guess i need to edit the question a bit.
All the problem seems to be with the root path. I fixed that problem with adding rootfstype=ext4 rw into the root section.
Now it is entering emergency mode. I tried to change the kernel from wheezy to jessie but it is still the same problem. What is going on?
I am sorry for silly question, but could you please tell: can KVM work without
libvirt?
From my poor experience I have seen KVM functionality which based on libvirt.
Thanks for your reply in advance.
I've used KVM without libvirt. libvirt is just a group that you assign a user to so that you are not rooted when you execute the virtual machine. You have to have qemu installed.
sudo apt-get install qemu
Then you would use the qemu package that supports the type of iso you are trying to install. Then you would write something like this
qemu-system-x86_64 -m 2048 -cdrom /path/to/Windows10.iso -enable-kvm
If you already have windows extracted onto the hard drive then you would write it like this
qemu-system-x86_64 -m 2048 -hda /path/to/Windows10.iso -enable-kvm
You can find out the different kinds of qemu packages that you have just typing in qemu in the terminal, and this will tell you the types of OSes that can be run inside of KVM using the specified package.
I am new to Linux Kernel Development. I have got the linux source code and added a Hello World system call just to get started. But now I am not able to figure out how to go about testing this code. How can I run the changed kernel?
I think I can use VirtualBox to check, but would not I have to make a new iso everytime I make a change and compile the kernel?
Sorry for asking such a naive question, but I am very confused here
You can launch a qemu virtual machine with an external kernel, so you don't need to keep modifying a disk image to test your kernel. For example:
qemu-kvm -kernel arch/x86/boot/bzImage -initrd initramfs.gz -append "console=ttyS0" -nographic
That example comes from this article which contains a lot of information on how to set up a development environment.
I want to emulate the friendlyARM board, the Mini2440 or the mini6410, so I can get to practice the embedded programming, the QT programming and this due to some financial difficulties and strange import policy in my country.
Anyway, the problem is that I can't seem to understand what's the first step to proceed the emulation: Am running ubuntu 12.04 on VirtualBox then, I installed the qemu-kvn-extras then what ?
Do I need a new kernel for qemu and the emulation process ? What's its specifications ?
In the other hand, when I read all of the tutorials in the net, I can't see the hardware specification part : I mean where is the part in the "qemu-i386 command" that refers to the fact that I'm using Mini2440 ?
After a long period of research, I don't know whether I can emulate the board so I can get used to the u-boot and cross compiling, etc.. or it's just a dream I can't reach ..
(Sorry for reviving an old thread but I had similar issues, so this might be useful for some other people, too)
To run my tests I used (see also man qemu-system-arm):
$ qemu-system-arm -machine versatilepb -cpu arm1176 -m 128M -nographic -kernel kernel.img
You might not want the -nographic here when you are testing Qt and need to replace kernel.img with the image you want to run. However, note that you need the ARM version of qemu qemu-system-arm. It will not work with the Intel version qemu-i386 as the mini6410 runs an ARM processor (the ARM1176JZF-S).
For me, connecting with gdb was also useful (-S halts the CPU at start, -s starts a gdbserver on port 1234):
$ qemu-system-arm -machine versatilepb -cpu arm1176 -S -s -m 128M -nographic -kernel kernel.img
And then:
$ arm-none-eabi-gdb
(gdb) target remote localhost:1234
By the way, host system can be any Linux distribution, so you do not need VirtualBox if your host is already Linux.
Another remark: I am currently struggling to get the interrupts to run on qemu (see also ARM Interrupt Handling in QEMU), so not sure if everything will work for you though.
Good luck! ;)
The closest thing I know about emulating the Mini2440 is that it's emulated on MAME.
The only problem is that you're not only stuck with the 3 pre installed OSes (Windows Mobile, old version Android and a Linux distro) but it's also slow and you can't connect to anything outside of the device itself.
You'll probably need a beefy computer if you want to run this, the beefier the PC is, the faster you can run it.
Plus, you can't use your mouse as a touch screen. You'll need to map out the touch screen controls that are already present in MAME if you want something like that.