The Pi boots from the card in the SD card slot. It can be configured to boot from a USB hard drive, or another SD card in a USB holder. A SD card in a USB holder can also be used as a data storage location Say, what? A Pi boots from an SD card. Period. You can have the root partition for the system...

fruitoftheloom wrote:NO

viewtopic.php?f=98&t=108585

viewtopic.php?f=44&t=72671

Thanks, for these links. I've made research but these ones are new for me.

Where did you get the idea you can use 2 SD cards (SD1)? As it was mentioned, I was wondering is it possible. The Pi boots from the card in the SD card slot. It can be configured to boot from a USB hard drive, or another SD card in a USB holder. A SD card in a USB holder can also be used as a data ...

Is there any possibility to boot from second SD card interface (SD1 pins, ALT3 RPi 1.2 B+)? It means that I need to use build-in SD card slot for user data access and add a second SD card slot adapter for start.elf, bootcode.bin, /boot/config.txt and OS files. Unfortunately GPU code is not open sour...