Messages in this thread | | | Date | Wed, 24 Dec 2008 13:37:59 +0200 | From | "Martin Schlemmer" <> | Subject | Re: Initramfs from existing vmlinuz |
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>>> On 2008/12/24 at 01:34 AM, Willy Tarreau <w@1wt.eu> wrote: > On Wed, Dec 24, 2008 at 12:28:53AM +0200, Martin Schlemmer wrote:
Hi Willy
>> I had a bit of an accident, and wondered if somebody already had to try to > extract the initramfs image from an existing vmlinuz? >> >> I did try google, but either my search terms was not right, or nobody > really touched on the subject before, because all the results mostly dealt > with an external image. >> >> Any advice will be appreciated. > > yes, it happens to me from time to time. > You first have to extract and uncompress the ELF image from vmlinuz. For > this, look for the gzip signature 1F 8B 08 in your vmlinuz, and feed all > data starting from this point to zcat. Either you do the same on the > resulting file -and you may find several compressed images- or you simply > pass it through "objdump -h". It will show you a .init.ramfs section. Use > the fourth field as the file offset, and dump from that position. You'll > find your initramfs, likely starting with 1F 8B 08 since it's supposed > to be compressed with gzip. > > You need an hex editor, dd, zcat and objdump for this. It's not much > complicated once you have the tools, but it might require a few attempts > before finding the right image (I tend to find config.gz before initramfs). >
Appreciated, I should be able to go from here now - just getting the starting point is sometimes the main issue.
Thanks
M
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