- Is it correct when I want to boot a Linux distro (Debian, Ubuntu, …) from the microSD card, and not flash it to the on-board flash memory, I every time when booting the BBB I have to push the “User Boot” button?
- If the answer on question 1 is yes what is the purpose of the microSD card besides using for installing a new Linux distro on the on-board flash memory?
This is not correct. BBB will look for a valid MLO header on your eMMC and then use that MLO to load and boot u-boot on the eMMC. The standard u-boot environment will check if a SDCard is installed and if so load uEnv.txt from the SDCard. Usually u-boot will load the zImage from the SDCard, uncompress and run the Linux kernel and then mount the distro filesystem.
There is no need to press the boot button. The purpose of the boot button is to load MLO and u-boot from the SDCard if there is something wrong with the MLO or u-boot on the eMMC.
Just got my BBB last week and was wondering the same thing. Just so I’m clear.
I’d like to keep Angstrom the way it is now, but try out Ubuntu without installing anything. Can I install Ubuntu on the microSD, power up with without hitting or holding the reset button to boot off the SD card and try out Ubuntu without anything done permanently?
As long as you have a factory (greater then 2013-june build) eMMC.
Many thanks for the clarifications.