How to extract the cpio archive in the kernel image?

[Michael Opdenacker <michael-lists@free-electrons.com>]

Hello,

Does anyone know a simple, command line way to extract the cpio archive 
embedded in a (compressed) kernel image?

That would be useful to modify the initramfs included in the kernel 
image even if one only has the kernel binary and sources, but not the 
initramfs sources.

Of course, it is always possible to get the initramfs contents from the 
running kernel and dump them somewhere, or to write a custom program for 
this purpose (accessing and uncompressing the embedded cpio archive as 
the kernel does), but it would be nice it there was a simpler way with 
regular Unix commands (I guess involving gunzip and cpio).

In a nutshell, how to open the penguin and still get the golden egg? ;-)

    Cheers,

    Michael.  

-- 
Michael Opdenacker, Free Electrons
Free Embedded Linux Training Materials
on http://free-electrons.com/training
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