[msumpter]

And that's why I moved over to MMC based Pi clones (specifically the Rock64), I am overly tired of SD cards mysteriously corrupting themselves. As of yet, I haven't had an MMC go upside down, but that's certainly far from guaranteed as well.

[zwieback]

Do you know how much of that is due to connector and signal paths? I worked on a design that had soldered on eMMC and it was rock solid (and 8 bit wide) but I always assumed SD problems were due more to the flaky form factor. Is there a standard for removable eMMC modules?

[copperx]

Is it possible for the rPi to boot from a USB device? One solution would be to hook it up to a $20 32GB SSD drive instead of relying on an SD card.

[wolrah]

Depends on the model, or actually technically it depends on the bootcode but which version is preloaded depends on the model.

The brand new Pi 3B+ ships with the latest bootcode and will boot from USB mass storage or PXE by default. Their PXE is a bit nonstandard but it's close enough that anyone who's PXE booted a PC will understand it.

The older Pi 3 supports USB and PXE booting, but has those modes disabled by default. There's a bit you can set in one-time programmable memory to enable it permanently. PXE booting has some quirks in this mode and doesn't get along with switches that take more than a second or so to activate ports.

Earlier models do not support anything but SD on their stock bootcode.

In all cases, a SD card containing nothing but the latest bootcode can be inserted which brings the new features to the older models, allowing them to boot the rest of the OS from whatever.

[ygra]

At least for the older models you still needed the card, but only for a marker that tells the Pi to boot from USB. I've been using that setup with Kodi/OSMC with a Pi 2 since USB is faster than the SD card.