Booting Diablo on external SD with chinook installed to flash --> ON A N810 ...as easy as A,B... through G

okay, so i wanted to setup a dual boot on my n810 rather than simply having a, what i'm gonna call a "clone boot". i had originally tried diablo on flash and chinook on external and that was easy. everything worked as it should. so then since i rarely boot to flash, i decided i wanted to make diablo my default boot on SD/mmc1 and have chinook on flash. this posed a bit of a challenge.

A. you need an external sd card with diablo currently installed. i prefer a clean diablo clone on an external card. there are many ways to clone your OS so i won't go into that here. and since you're a civilized person, you're already on a linux pc so you can run the flasher-3.0 tool (sorry, winblows users, this guide won't help you much).

B. optional but recommended. reflash diablo to n810 internal flash (this gets diablo's initfs, bootloader, kernel, etc loaded to flash which is needed to not brick your n810 after a diablo update from mmc1). note: you don't need to do this if you already have diablo installed on internal flash. tho i'd still do it for a squeaky clean install. i had my external SD card not installed when i did this.

running the above command should give you something like this:
C. now flash just chinooks rootfs to internal flash. shut down diablo and use the command from your linux pc:

or, if you have not unpacked your fiasco image you can run:
# sudo ./flasher-3.0 --flash-only rootfs -f -F RX-44_2008SE_2.2007.51-3_PR_COMBINED_MR0_ARM.bin -R

running either of the above commands should give you something like this:
now boot into flash and you should see a fresh install of chinook running diablos initfs and kernel. if you want to check the kernel version, type this in xterm:
and it should give you this:
Linux 2.6.21-omap1 Wed Jul 16 12:29:11 EEST 2008 is diablo's initial release. make sure everything is working as it should then shutdown chinook.

D. now install your external sd card that has your diablo install. then set the root device of your n810 to mmc
and it should give you something like this:
E. boot into diablo on mmc1 and run updater via control panel. update to the latest OS2008 feature upgrade.

F. after updating diablo to latest OS2008 feature upgrade, run fanoush's initfs_flasher (thanks fanoush for the awesome work btw) and setup dual boot (i've read that you should be wary of running the initfs_flasher from an exteranl card, but it seems to be working for me. so boot into flash/chinook and run initfs_flasher if wanted - just more work with future updates, etc).

done! reboot into each OS and make sure everything is as it should be. G & H are optional.

G. optional: make boot menu appear when powering on. run as root from your nit's xterm:
H. now run a quick check from flash for your SD card. from chinook/flash run from xterm with e2fsprogs installed:
note: i have only done this on my n810. i do not know if this will work on a n800/n770 as i have not ever owned one before. i'm still fairly new to my n810 so hopefully this guide will help others. enjoy at your own risk.

jbk