Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I want to use an uncompressed kernel image and boot the BeagleBoard. Generally I use uImage to boot the kernel which is in compressed format. How do I use an uncompressed kernel image?

share|improve this question
You are using U-Boot as the bootloader, right? – Gilles Feb 6 '12 at 23:43
yes! Is it possible using uboot? – Sharanya Feb 7 '12 at 5:56

As far as I know, U-Boot cannot directly boot a “raw” ELF image (vmlinux). You need to turn it into the uImage format, which contains the compressed vmlinux plus a few extra bytes of metadata that describe the kernel load address. U-Boot FAQ 2.19 explains how to generate uImage; it's fairly straightforward, using the mkimage utility in the U-Boot source tree:

 mkimage -A arm -O linux -T kernel -C gzip … -d vmlinux uImage

(You may need extra parameters indicating the load address.)

share|improve this answer
Uncompressing the uImage while booting takes some time. I need to minimize that. So i thought why dont i try with the uncompressed raw file vmlinux. – Sharanya Feb 7 '12 at 5:55
The effect you want to achieve might be opposite to intended. Decompression time is usually smaller than time of copying data from flash. – Maciej Kucia Aug 25 '13 at 20:46
 mkimage -A arm -O linux -T kernel -C gzip … -d vmlinux uImage

Change gzip in the above example to none, and you'll create a u-Boot compatible uncompressed image.

share|improve this answer

If you are using Buildroot, select a uImage kernel output file (BR2_LINUX_KERNEL_UIMAGE=y). Compile normally and Buildroot will also create a vmlinux file in an intermediate step. While the vmlinux file is not copied to the /output/images directory it can be found in ./output/build/linux-custom/(or by running find . -name "vmlinux").

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.