[U-Boot] Combine zImage and rootfs in single uImage

[Grant Edwards]

Currently, I build a linux kernel that contains the root fileystem in
the zImage file, when then gets converted into a uImage and booted
from NAND flash.  This is all working fine, but having the kernel
build depend on the rootfs build is a problem.

In another mailing list, somebody told me that if I was using U-Boot,
I could build the zImage and rootfs separately and then combine them
into a single uImage file for distribution.

I've been looking through the manual and FAQs, and can't figure out
how to do this.  I did find a vague reference in one of the Linux
kernel docs that some bootloaders will detect any "extra" bytes after
the end of the zImage data and assume that they are a rootfs image. Is
that how U-Boot does it?  I just cat the ziminage and rootfs.cpio.gz
files together and then prepend a uImage header?

-- 
Grant Edwards               grant.b.edwards        Yow! I selected E5 ... but
                                  at               I didn't hear "Sam the Sham
                              gmail.com            and the Pharoahs"!