Hi RobertCNelson,

Thank you for your response! Actually, I "need" to run Linux from the eMMC 
since I want the data to sit on the µSD card (for convenience). And I want 
to maximize the storage space on the µSD card, so no Linux on there.

By the way, the "hardware" method still works on my BBB rev B (the tests 
were concluding: after 824 reboots, no sign of U-Boot crashing).

Regards,

Alexandre

Le jeudi 14 août 2014 21:02:28 UTC+2, RobertCNelson a écrit :
>
> On Thu, Aug 14, 2014 at 9:20 AM,  <[email protected] <javascript:>> 
> 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/ 
>

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