+++ Christopher Covington [2013-11-27 11:17 -0500]:
Hi Wookey,
There is a wiki page somewhere for wrapping your own kernel with bootwrapper foo, but I found it much easier to use a handy internal tool which rewrites the kernel command line inside a .axf file, which makes it a one-liner to turn a working OE kernel .axf from linaro snapshots into one that works for an ubuntu image.
This is nothing more than some unpacking + objdump runes, but of course being arm-written software (by Jim) would probably take months of tiresome effort arguing with lawyers to get it released, so you can't use it. :-(
It could get turned into a wiki page of runes if there is demand...
In my opinion, the nicer solution is to port the semihosting boot wrapper to 64-bit. We've done that internally, but don't currently have approval to share that work. It's not too difficult though--basically just drop the AArch64 boot.S into the 32-bit bootwrapper code with semihosting support and you're most of the way there. A simulator with instruction tracing or stepping is probably necessary for debugging.
I didn't understand a lot of those words, but it really doesn't sound easier than 'a little shell script that lets me change the command line in a working .axf kernel'. Turns out said shell script was actually written wearing a linaro hat so I'll stick it somewhere and add a wiki page.
Wookey