thoughts for next steps...

Jarielle Catbagan jcatbagan93 at
Wed Jun 24 14:35:00 UTC 2015

On Wed, Jun 24, 2015 at 7:17 AM, Ed Sutter <ed.sutter at> wrote:
> On 6/24/2015 10:12 AM, Gedare Bloom wrote:
>> On Wed, Jun 24, 2015 at 9:37 AM, Ed Sutter <ed.sutter at>
>> wrote:
>>> Jarielle,
>>> Something to consider...
>>> I think the next two big steps are:
>>> - Init DRAM
>>> - Boot standalone (using uSD instead of UART)
>>> I believe your current plan was to work on DDR-init next; however it may
>>> be
>>> better (your choice, just adding my 2cents) to consider booting from
>>> microSD
>>> as the next task.  Here's why I say that...
>>> As you are playing with DDR-init you'll have to do a lot of restarting
>>> the
>>> board.
>>> Each time you do that, you'll have to reboot using Xmodem.  This requires
>>> a
>>> few manual steps: hold boot button while power cycling, then issue
>>> xmodem...

If I am understanding you correctly, I actually don't have to power
cycle the board anytime the board hangs.  I just simply reset via the
reset button and then issue an xmodem transfer again without touching
any cables and restarting my terminal emulator.  I hope I did not
misunderstood you :-)

>>> Alternatively, if you get the boot-from-uSD card stuff working, and then
>>> erase
>>> the eMMC (causing the cpu to automatically boot from uSD), you should be
>>> able to just push the reset button to restart a locked up board.
>> In other words, it has a tighter develop-execute-debug loop.
> Exactly.
>>> It would just be easier (IMHO) if the board could reset with this basic
>>> uMon
>>> image
>>> (what you have running now) by default.  Know what I mean?  If yes, what
>>> do
>>> you think?

I think it's a great idea.  Yesterday I was deciding what I should
finish first, which was either DDR-init or boot off of an uSD card.

I will definitely start getting the uSD card booting to work as soon
as possible.

Right now I am at my university (taking summer classes) and I don't
have access to an uSD card (left it at home).  But I did bring my
Beaglebone Black with me as well.  So I'll continue working on
DDR-init, and when I get home I'll immediately start working on
getting Umon to boot of a uSD card.

>>> Ed
>>> _______________________________________________
>>> umon-devel mailing list
>>> umon-devel at
> --
> Ed Sutter
> Alcatel-Lucent Technologies -- Bell Laboratories
> Phone: 908-582-2351
> Email: ed.sutter at
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> umon-devel mailing list
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