[U-Boot] Use u-boot to recover bricked NVIDIA SHIELD TV.

[Matthew Gorski]

On Mon, Jun 19, 2017 at 11:53 AM, Stephen Warren <swarren at wwwdotorg.org>
wrote:

> On 06/18/2017 04:46 PM, Matthew Gorski wrote:
>
>> I am curious if there is a possibility to recover a wrongly flashed
>> NVIDIA SHIELD TV device by flashing u-boot instead of cboot and mounting
>> the emmc in uboot to do some repairs.
>>
>
> The NVIDIA SHIELD TV is a production Android device, and hence I'm pretty
> sure it has boot security enabled. This security also applies to the USB
> recovery mode protocol, so I don't believe you'll be able to communicate
> with the device unless you know the system's keys, which I assume you don't.
>
> There is some support for flashing generic upstream Linux onto the NVIDIA
> SHIELD tablet, but I believe that relies on  making (at least some of) the
> modifications from a running system, so if your system isn't booting, I
> don't expect this will work either. Just in case it's useful, see:
>
> https://github.com/linux-shield
>

Thanks for chiming in Simon and Stephen.  I appreciate you both taking the
time out of your busy day to answer. I figured the boot security was
preventing communication to the USB recovery mode protocol.  I tried
tegrarcm just to see if I could read the bct and no go.  Seems this happens
quite a bit and there is no way to recover and NVIDIA will not do any
repairs after the warranty expiration date.  Would have been nice if
fastboot could have recognized I used the wrong package :/  Maybe a crc
check to see if the system images match up to the correct device.

Is there anyway to determine what mode I am currently in with tegrarcm
(assuming I can even get communication)?

Operating Mode:          0x3 (developer mode)


Simon the soldering solution sounds interesting.  If someone can elaborate
on that just for reference that would be great.  Ive always wanted UART on
foster.  Thanks again guys for your input.  I'll try a few tricks just to
see what happens and report back.