So, I'm trying to get my 770 to boot off the RS-MMC card but I'm running into some problems.
I've tried following this guide to the letter, but I wasn't able to get it to boot. It would "fail to boot" then continue to boot from flash. I fsck-ed and it found numerous errors. I suspected that the device ran out of memory, so I reflashed my device and retried, but this time enabling swap. Same result, failed to boot.
I tried again, but this time with my own configuration based on the guides. Still no luck.
Here is what I exactly did on the device, in step by step format:

Downloaded and unpacked tar to /tar-temp/
Disabled swap in GUI
Ran the following commands:
It was my intent to create one large EXT2 partition, which my mac has no trouble mounting.
When it started back up I ran these commands:
While the files were copying I created a small script to pipe the contents of `free` to a text file every 60 seconds. I walked away, came back, and checked the file. It didn't run out of memory at any point.

I also modified /mnt/inifs/bootmenu.sh in the following way
I'm at a loss... I don't see any error in what I'm doing. Help!

I had a problem also, at the final stage when copying the whole OS to the MMC XTerminal would just shut down. Found out it was because it ran out of memory so crashed, if it completes this whole operation and doesnt shut down XTerminal then its probably not the same issue. Sorry

Probably worth running through each command in person rather than doing them all at once, you maybe able to work out where it's going wrong

I followed this guide: http://examplified.net/guide/Nokia_7...ting_from_MMC/ It's very similar to Maemo Wiki guide but goes into more detail (and slightly different in places) I used that guide second time around and it worked perfectly

I did do these all in person, its just easier to list them all at once. This wasn't a shell script, I just made it up on the fly. I made sure each process completed.
I did them over an SSH connection and ran them in a background process (&) and piped the output to stdout. That way if my SSH connection did drop the process would (hopefully) complete. I didn't get dropped from SSH once during the entire process. I believe they all completed successfully...

So... I was demonstrating to a friend the procedure that was failing to work.. but this time it worked! I flashed to the Nokia original, then repeated my steps exactly as outlined above and it worked perfectly.
The only possible explanation I can think of is when I was copying the data over to my flash drive it somewhere got corrupted (All 5 different attempts) or my device is faulty in some way. Weird.
It would seem that the observer effect is indeed powerful