In this video, I talk about USB drive options to use with a Raspberry Pi and I do an overview of configuring a Pi to boot from a USB drive. In the video, I install Ubuntu 14.04 LTS on a Raspberry Pi 2. This also works with Raspbian which will work on a Raspberry Pi 1 or 2.
NOTE: An SD card is still required because the Raspberry Pi doesn’t have a traditional BIOS and thus stores initial boot information on the SD card. See https://www.raspberrypi.org/help/faqs/ and look for “13. HOW DOES IT BOOT?”.
In this video, I install the HDHomeRun Live TV Add-on on a Raspberry Pi 2 running OpenELEC. I am connected to an HDHomeRun EXTEND using internet540 transcoding. I am controlling the Raspberry Pi vi HDMI-CEC. I recorded this using an Elgato Game Capture HD60.