Bricked Tegra device

[Tapewolf]

Anyone familiar with nvflash?

I seem to have screwed up my Toshiba AC100 by upgrading it to Android 2.2.  Previously I had a custom bootloader in slot 5 which would boot linux from the SD card, but it was also possible to install the kernel in partition 6.

Since updating it to 2.2 it no longer seems to be booting partition 5 or 6 - it is apparently doing something entirely different.  This is extremely annoying because I was hoping to bring the device to AC instead of my old EeePC...

[Tapewolf]

Right.  In the unlikely event that anyone else here ever needs to de-upgrade a Toshiba AC100 from 2.2 back to 2.1 - and I'm assuming that you did follow the instructions and backed up your partitions first - this information may prove useful.

Toshiba's 2.2 upgrade appears to modify the bootloader in partitions 2 and 4.  After this happens the SOS image (5) will no longer be booted in the same manner and you won't be able to boot into linux as before.

Unlike the other partitions, which can be reflashed via the usual --download option, the bootloader and its friends are special and can't be restored that way.  What you have to do instead is:

LD_LIBRARY_PATH=. ./nvflash -r --rawdevicewrite [StartSector] [NumSectors] filename.img

...numbers will vary according to your partition table, which can be obtained with:
LD_LIBRARY_PATH=. ./nvflash -r --getpartitiontable partitiontable.txt

In my case Part2 started at 0 and was 1536 sectors long.
Part4 began at 1792 and was 1024 sectors long.

...Android is probably still stuffed at the moment but I should be able to fix that.  More important for me is that it can boot linux off an SD card again.

[Source:  http://tosh-ac100.wetpaint.com/page/Backup+and+Restore  ]