Once Booted from MMC, eMMC not found

[Ian Lepore]

On Fri, 2015-07-03 at 12:00 -0700, Tim Kientzle wrote:
> > On Jul 2, 2015, at 9:46 PM, Glen Barber <gjb at FreeBSD.org> wrote:
> > 
> > Hi Tim,
> > 
> > On Thu, Jul 02, 2015 at 09:40:22PM -0700, Tim Kientzle wrote:
> >>> On Jul 2, 2015, at 7:35 AM, Glen Barber <gjb at FreeBSD.org> wrote:
> >>> 
> >>> I'm curious - is this even necessary to do anymore?
> >>> 
> >>> My latest tests (11-CURRENT and 10-STABLE) of BeagleBone Black images
> >>> "just boot."
> >>> 
> >>> Maybe I don't understand what this script is supposed to fix.  Can
> >>> someone clarify that for me?
> >> 
> >> The script just copies a running system booted from SD onto the eMMC so that a BBB can boot without an SD card.
> >> 
> >> The script just does the following:
> >>  * Erases the eMMC
> >>  * Reformats it
> >>  * Copies boot files from SD to eMMC
> >>  * Copies / from SD to eMMC (excluding a few things like /usr/src, /usr/obj that are unlikely to fit)
> >>  * Tweaks a few configuration parameters on the copied system
> >> 
> > 
> > Ah, okay, this is the part I was missing.  I misunderstood what the eMMC
> > did overall, and wasn't sure how this interacted with the system in
> > whole.
> 
> The eMMC chip is connected to the second SD/MMC interface on the SoC.  To the kernel, it should look just like a second SD/MMC card on the second interface.
> 
> BBB can boot from eMMC to create a nice self-contained system.  At one time, Crochet’s BBB images could be easily copied to eMMC to boot from there without an SD card, but this doesn’t seem to work anymore due to changes in FreeBSD somewhere.
> 
> I stopped using the eMMC for booting myself simply because 2GB wasn’t enough for the things I was trying to do.  There are now BBB with 4G eMMC chips, so that may be worth looking into again.
> 
> Tim

Some changes in the mmc driver related to ancient msdos geometry stuff
caused failures for a while (a long while).  Those changes have been
undone (as of r283754 about a month ago), so I would expect that the
copy script would work again now.

In the case of the OP's problem, it was related to using 10.1-RELEASE,
and it's known that that release was broken in several ways on armv6.
10-stable (and hopefully the upcoming 10.2-RELEASE) should be fine.

-- Ian