On Tuesday, November 25, 2014 5:11:56 AM UTC-8, Gerald wrote: > > CCCC means the SD card is unreadable as a boot source and it cannot read > the eMMC either. It is looking for a boot source.
So you are saying that even though it was previously booted from the uSD, and was not power cycled, it would boot from the eMMC if the uSD was not available? I have a fully bootable image on my eMMC, so if it didn't take over and boot, that would mean something had blocked access to both uSD and eMMC. Removing the uSD and pressing Reset did not make the eMMC boot, so if your scenario is true the eMMC block survived Reset. Re-inserting the uSD with no further Reset lets it boot, so what could have been blocking both storage devices that merely inserting the uSD could fix? I was under the impression that only a power cycle could switch between uSD and eMMC. But SRM 6.8 does sort-of match your scenario: --- If you have a microSD card from which you need to boot from, hold the boot button down. On boot, the processor will look for the SPIO0 port first, then microSD on the MMC0 port, followed by USB0 and UART0. In the event there is no microSD card and the eMMC is empty, USB0 or UART0 could be used as the board source. --- But the language is not exactly clear... A slightly different view: <http://diydrones.com/profiles/blogs/booting-up-a-beaglebone-black> ----- The boot sequence is as follows : eMMC->microSD->USB port->serial and in the case that the boot button is pressed the sequence becomes microSD->USB port->serial. ----- That has been my understanding, that with the boot button held, eMMC will not boot even if the uSD is missing. The flowchart on that page says the sequence is traversed only once, but my experience shows it continues looping through all the available options. I do think their sequence is correct, though, as making the eMMC un-bootable will start the sequence at the uSD. Loren -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
