Joe Schmoe wrote:Let's be fair here. Of course you can boot from USB - as long as you interpret that phrase correctly. It is understood that by "booting from USB", people mean that the OS is on a USB drive.
But people do understand, of course, that you still need an SD card for the initial phase of the boot.
I'm afraid that I don't share your faith. From the tenor of the questions that pop up on the subject, I think there are a fair number of people who think that you can boot from a USB stick without using an SD card.
Just as they understand that when you boot a PC, the initial phase of the boot process is in the BIOS. But they still say that they are "booting from the hard disk".
Yabbut... The BIOS is part of the PCs hardware, in that the chips containing the BIOS code are physically part of the motherboard. The better analogy would be, I think, booting a PC from a USB stick or CD. That "looks" the same from a user perspective as "booting from the HDD". Therefore I suspect that at least some of those that ask the question are looking for an equivalence where USB on Pi == USB on PC, without understanding that there is no BIOS in the Pi that can handle multiple different boot devices. All that capability resides on the SD card.