TX2 OTA full disk flashing?

[zach-welch-aquabyte]

I am working with a TX2-based product that currently runs an older version of Yocto built using meta-tegra. For various reasons, we want to update the entire eMMC in a device with a new image; however, our deployed devices are all but physically inaccessible, making the normal USB flashing scheme extremely impractical and expensive.

To avoid having to retrieve and crack them open for reprogramming, I want to use a script to pivot the running OS into a tmpfs, allowing a new disk image to be downloaded and written to the eMMC on the fly before rebooting. After some digging, I realize that the Yocto build process does not create a suitable image that can be written directly in this manner, as the flashing scripts assemble the pieces on the fly to send via USB.

Thus, I am searching for a method to generate a suitable image as a file on my development host. While I am not seeing a simple path to accomplish that goal for the TX2, I found a method for cloning a TX1 that might be adapted to obtain an image from a freshly flashed device, but the language on that page implies that the resulting image will not be suitable for upgrading a fleet of devices in the manner that I require.

Is there a documented process that I could follow to generate the required images, either directly via bitbake or indirectly by using the tegraflash archive that it produces? Or is USB flashing the only viable means to reflash the entire device?

[dwalkes]

@zach-welch-aquabyte we've had some discussions about this in the past, and there are a few pieces implemented which might be useful. I'd suggest https://github.com/OE4T/meta-tegra/wiki/Over-the-air-reflashing-process and the links there as a jumping off point. Others might chime in here who have worked on this.