On Thu, Aug 14, 2014 at 9:20 AM, <[email protected]> wrote: > Hi all, > > I work with a BBB for a project where the I need to record data from an > Ethernet connection. The OS sits on the eMMC while the data goes to the µSD > card. To boot from the eMMC while there is a µSD in the slot, I followed the > instructions on this post (formatted µSD card with 2 partitions, put a > uEnv.txt file on the first one) and got the board booting on the eMMC. Yay. > Since the power is intermittent, the BBB is equipped with a battery that > lets it turn itself off (in case power is gone). When power is back on, the > board boots again. So the BBB needs to be able to boot autonomously when > there is power on USB and to turn itself off afterwards. I did the shutdown > with a script and this part works fine. (of course there is always the case > where the power is back on just when the BBB is shutting down, but I guess I > can't do anything about it). > > What does not work is that I sometimes find the board in a strange state, > where only the power LED is lit while the user LEDs are off. It seems that I > am encountering the issue discussed in this thread, where the RX pin of the > FTDI receives fake data, which stops U-Boot and prevents the board from > booting normally. > > After reading the whole thread, two solutions seem to exist: > > hardware fix: use a 10k pull-up resistor between the RX pin and the 3.3V > software fix: reconfigure U-Boot to look for a string (instead of just any > data) to enter into its communication mode > > I have implemented the hardware fix and am currently testing it (booting > every five minutes). However, I would rather use the software fix to U-Boot > as it does not require any modification to the hardware. So I followed the > link on this post (to eewiki.net) to build U-Boot from the official git > repository and created MLO and u-boot.img files (that I can patch with the > few lines on the post, but I haven't done this yet). My problem is: those > instructions are designed to make the BBB boot from the µSD card. Actually, > it even requires to remove the OS from the eMMC (or to remove the MLO file > so that U-Boot doesn't see it), or to replace the uEnv.txt by the one there, > otherwise it is stuck. My files work, as I can boot from a µSD card > containing Linux. However, when I tried replacing the MLO and u-boot.img > files on the eMMC (you can't blame me for trying, but I agree that it was a > long shot), it of course hanged.
You can also follow those directions for setting up the eMMC, while running the bbb from the microSD.. Regards, -- Robert Nelson http://www.rcn-ee.com/ -- 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.
