I did some investigations into recovering from a GSOD on the tivo, when there's insufficent swap space.

I was able to trash the spare root partition, and replace it with a swap partition, and the tivo seemed happy.

I wasn't actually having the GSOD, and I've never seen one, so I wanted to try it.

I found the instructions for forcing a GSOD, entering "mfsassert -please", which resulted in:

Filesystem assert: false && "mfsassert" at fsassert_main.C line 40 in int fsass)Filesystem flagged as inconsistent!
Tmk Assertion Failure: false && "mfsassert"
    int fsassert_main(int, char **), line 40 (fsassert_main.C)
Tmk Fatal Error: Thread mfsassert <195> died due to signal -2
1aa90ac 1aa79c8 1a962a8 1a91980 1ce61fc 1800134

Hmm, that looks nasty. (and it does it every time I do it, even on different disks).

The tivo rebooted, and got stuck on the PROM screen.

I assumed that because I'd forced it to do the GSOD, it had decided to use the inactive root partition.. which was now a swap partition.

I couldn't check the bootpage settings, because the factory password wasn't being accepted.

I used another disk, reset the password, and was then able to access the boot prom.

I checked the boot settings, but they were correct, so I couldn't understand why the disk wasn't booting. It was still trying to boot off the normal root partition, so it should have just worked.

I ended up recreating the second root partition, and copying the contents of the first one on to it, and then the tivo booted. It came up, went through the GSOD I'd forced, completed it in only a few minutes, rebooted, and came up fine.

I was using a different method os imaging the disk, so I found an old cd, which I suspected had an issue caused my mfstools 2.0, causing the fsfix to crash, but this wasn't case, I was able to force a gsod on that older disk, and it got through it.