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.
Gerald On Tuesday, November 25, 2014, Loren Amelang <[email protected]> wrote: > My Rev.A6 BBB had been running solidly 24/7 for months, with only > explainable software-related crashes. But in the last week it has just hung > twice, with no relation to software functions, nothing unusual in the logs, > and D2/3/4 on solid. > > It is powered by an analog regulator from my solar house battery system > with huge and redundant battery banks, so there is really no chance of a > power glitch. It runs the RCN distro of Ubuntu 14.04, from a 16 GB SanDisk > uSD. When it hangs and I press Reset without cycling power, I get no user > LEDs, but I do get a series of "CCCCC" characters on the console port. > > My A6 SRM says: > --- > Without holding the [boot] switch, the board will boot try to boot from > the eMMC. If it is empty, then it will try booting from the microSD slot, > followed by the serial port, and then the USB port. > --- > But that is for a power cycle boot. Reset alone, with constant power, > "does not change the boot mode". Apparently that means does not change > between eMMC default and uSD default for the first try, but still allows > for Serial or USB boot if the default local storage fails. > > Later it says: > --- > 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. > --- > It is not clear whether USB and UART/Serial are checked in a particular > order, or are continuously checked. My experience seems to suggest that > Serial, at least, is continuously checked, and that uSD is also > continuously checked: > > If I remove the uSD while the "CCCCC" is streaming on the console, nothing > obvious happens. If I then re-insert the uSD, booting begins instantly and > proceeds normally! > > So, I'm guessing the uSD somehow loses contact with its socket, and an > access from the BBB fails and hangs Linux, with the LED that seems to > indicate uSD access on solid. But I can't see any problem inside the uSD > socket, and the contacts on the uSD itself look perfect. And this uSD > socket has a relatively easy life compared to those in my phone or other > portable/remote devices, which have never glitched on me. > > So what else could this be? An electrical failure inside the uSD card? > Guess I should try a power-cycle reboot without mechanical disturbance next > time it happens... > > -- > 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] > <javascript:_e(%7B%7D,'cvml','beagleboard%[email protected]');> > . > For more options, visit https://groups.google.com/d/optout. > -- Gerald [email protected] http://beagleboard.org/ http://circuitco.com/support/ -- 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.
