Hello all, i've seen the tutorial for booting images from SATA, but i'm tryin to boot images from USB drive. Is it possible to do that? I can't modify u-boot env properly. Could someone help me? Thanks
As far as I can tell booting from USB flash is not possible. U-Boot appears to lack drivers for the i.MX6 USB host (and OTG) controllers, and even if those existing, initializing usb-storage from that limited environment probably isn't feasible. The closest thing would be to load a kernel and initrd from micro-SD, then pivot to a root filesystem on USB, which should work similiarly to doing the same with a SATA drive as root filesystem - see past discussions here of that. The i.MX6 CPU has a USB "serial downloader" mode, described on page 393 IMX6DQRM.pdf, for spooling in a boot image from a computer, but that seems intended for recovering a bricked device (onboard flash corrupted - not applicable to Udoo) or initial factory setup. It seems to require chanigng BOOT_MODE pullup/pulldown resistors, and wouldn't work with a simple USB flash stick in any case.
