SRM aside. Gerald was saying that "CCCC...." indicates that no boot-able media was found. if "we" stop and think about this for a minute multiple situations can cause this issue. Not least of which is physical sdcard bracket is loose, and the media over time got screwed inside of it.
I've had this happen to me for inexplicable reasoning. I've taken the sdcard out, blown it off, and have had it immediately start working again. Why ? No idea . . . On Tue, Nov 25, 2014 at 10:21 PM, Loren Amelang <[email protected]> wrote: > > 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. > -- 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.
