HI i want to run profiling on Kernel using Oprofile but it requires uncompressed vmlinux image and ubuntu 10.10 provides vmlinuz which is stripped and compressed. Pls help
You may need to rebuild the kernel from source or find an uncompressed copy of vmlinux. The vmlinuz file is stripped of symbols along with the ELF header to save space, and are needed for oprofile.
See this answer on Superuser for how to install an uncompressed (debug) version of your kernel.
Related
I need to know the version of a kernel file without running it. Therefore, the following questions arise in this realm:
Is it possible to get the kernel version in the u-boot environment? I mean before running the kernel I want to get the version of my kernel file.
Suppose I am running ubuntu on my amd64 processor and I have a zImage file which is cross compiled for ARM processor. Therefore I can not run this zImage file on amd64. Then how can I get version of this zImage file without running it on an ARM processor? I checked out uname manual but it does not accept a file as argument. I also issued readelf -V on a vmlinux kernel file, but it was an unsuccessful attempt.
I am compiling Linux Kernel to my ARM board. I have seen file called vmlinux generated in kernel root folder. Can someone give good explanation about this file and it's use.
vmlinux is a ELF format based file which is nothing but the uncompressed version of kernel image which can be used for debugging. The zImage or bzImage are the compressed version of kernel image which is normally used for booting.
The vmlinux as such directly cannot be used by UBoot. However, by addition of metadata info in the process of creation of uImage for vmlinux, it is possible to boot via UBoot.
The vmlinux is the boot file in ELF format, and then the initrd file (ram disk) is run in the same directory (/boot).
The vmlinux file is practically the kernel itself.
I recently heard about Breach, a Node.js based browser. I was following the instructions on http://codeforgeek.com/2014/08/download-install-breach-browser-ubuntu-14-04/ to install it but got the following error :
breach-v0.3.22-alpha.6-linux-x64/__AUTO_UPDATE_BUNDLE__/exo_browser/exo_browser: cannot execute binary file: Exec format error
After some googling, I found that it is because I am trying to install the 64 bit package on the 32 bit Ubuntu installation. I tried to find 32 bit package of the same but ended up with no luck. The browser is only available in 64 bit packet(as far as i know).
So, My question is :
Is it possible to somehow install it on the 32 bit OS or if any program available which can run 64 bit applications on the 32 bit OS.
I have been googling around and found no help. Can anyone help me?
I am using Ubuntu 14.04 (32 Bit).
Thank You
I have faced similar problem with c files .I think it has some thing to do with the compiler which we use
My kernel version is
3.13.0-40-generic
which you get by executing the command uname -r in terminal .
I had a code file which does file operations. When I used GCC with appropriate flags and created an object file called "fileop" and tried running it
I got the following error .
"bash: ./fileop: cannot execute binary file: Exec format error"
My executable linkable file was 32bit which you can see by using command
"file fileop"
fileop: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped
But when I used "CC" instead of GCC, It created a out file called a.out and I was able to execute it without any issues.
The "file" operation yielded the following ouput
a.out: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1] =13b7ad302580a0c7f5c7931ec2d80155d7915fa9, not stripped
Hope the above Description sheds more light in to the issue.
It is not possible to (directly) run 64 bit binaries on the 32 bit system.
You could try to use VMWare to run 64 bit Linux on the 32 bit host. See this answer for details.
Also, by inspecting Breach's landing page, I found this:
if(arch === 'ia32') {
$('#download').html('Available on <span class="fa fa-linux"></span> x64');
$('#download').attr('href', '#');
/*
$('#download').html('<span class="fa fa-linux"></span> Download Breach Alpha v0.3 (ia32)');
$('#download').attr('href', 'http://bit.ly/1kWWjmF');
*/
}
This indicates that they are working on the 32 bit Linux support. Maybe ask developers on Twitter/Github on status of that?
I'm trying to compile a kernel (altered version of 2.6.32.9, found here https://github.com/rabeeh/linux-2.6.32.9). I am doing the compilation on a emulated ARM system (qemu) (yes, I should probably cross-compile, but that's a different topic) running Ubuntu Core (https://wiki.ubuntu.com/Core) and the kernel (vmlinuz) from Ubuntu 11.04 (downloaded from http://ports.ubuntu.com/ubuntu-ports/dists/natty/main/installer-armel/current/images/versatile/netboot/vmlinuz).
After running make bzImage, I look in the arch/arm/boot folder, and find only a file called zImage. I tried using this zImage instead of the vmlinuz I downloaded from ubuntu.com in qemu, but that doesn't work, just shows a black screen. I guess zImage is not the same as bzImage, which is what I think vmlinuz (judging from different articles on the internet) is.
So, a few questions:
Why doesn't make bzImage produce a bzImage/vmlinuz?
Can I convert a vmlinux to a vmlinuz using for example mkimage (there are lots of guides on the opposite...)?
Thanks
The bzImage filename and make target was originally x86-specific (big zImage). Many of the bootloaders on architectures that are not equal to baremetal-x86 (SPARC, PPC, IA64, etc. and also Xen on *) directly take vmlinux (or one of its compressed forms, for example vmlinux.gz, aka zImage). I guess some maintainers just added bzImage as a make target name because they wanted to have the x86 madness on their arch as well.
I get the result you describe by asking qemu to emulate a different cpu than arm926ej-s. But booting versatilepb with the default cpu works. I've cross-compiled my kernel, and I compiled all the drivers into it (so I don't use initrd).
Just download 100MB arm-eabi toolchain from http://www.mentor.com/embedded-software/sourcery-tools/sourcery-codebench/editions/lite-edition/ (it's free but they want your email, like the x86 Intel compiler). It has an installer, just say "next" until it's done, like on Windows. Then add the bin directory to your path:
export PATH=~/CodeSourcery/Sourcery_CodeBench_Lite_for_ARM_EABI/bin/:$PATH
Then go back to your kernel source dir and do
make ARCH=arm CROSS_COMPILE=arm-none-eabi- menuconfig
make ARCH=arm CROSS_COMPILE=arm-none-eabi- zImage modules
You can do
sudo make ARCH=arm CROSS_COMPILE=arm-none-eabi- INSTALL_MOD_PATH=path_to_arm_root modules_install
if you can reach your ARM filesystem from the host. If you're using NFS root it's trivial, but if you're using a disk image you need to either:
use a raw disk image and kpartx (depends on your host kernel having dm-multipath) or
qemu-nbd which supports qcow (and depends on host kernel having network block device support)
To boot in qemu with disk you need the right drivers (SYM53C8XX SCSI). The versatile defconfig doesn't select those.
After a Xen guest domain hang, I took a dump using xm core-dump . Following the sparse documentation I found, I tried using the crash utility to analyze the dump.
Unfortunately, the kernel image (Debian lenny) is stripped, so I am forced to make use of the map file.
However,
crash
/boot/System.map-2.6.26-2-xen-amd64
vmlinux-2.6.26-2-xen-amd64
/mnt/my-core-file
(with vmlinux-2.6.26-2-xen-amd64 being the gunzip'ed vmlinuz image) fails:
crash: vmlinux-2.6.26-2-xen-amd64: no
debugging data available
Then I read that current Xen versions produce ELF-compatible dumps for guest domains. Indeed, this seems to be the case:
~$ sudo file my-core-dump
my-core-dump: ELF 64-bit LSB core file x86-64, version 1
However, gdb vmlinux-2.6.26-2-xen-amd64 my-core-dump fails, too:
...is not a core dump: File format not
recognized
Any hints?
Have you tried attaching to the domU console ?
xm create domU.conf -c
On the subject of the core-dump file, I found this:
http://lists.xensource.com/archives/html/xen-devel/2006-12/msg00456.html
I just want to check that you aren't under the impression that 'xm
dump-core' emits an Elf core file. It doesn't -- the format is custom and as
far as I know is only interpreted by a set of gdbserver patches that we ship
in our repository. Does the crash utility really support this special
format?
Edit: This might help to debug the core-dump: http://os-drive.com/files/docbook/xen-faq.html#setup_gdb