BBB: Add "mmc" command that interfaces to the onboard eMMC

Ed Sutter edsutterjr at
Tue Aug 4 23:17:36 UTC 2015

Great!  Looks good.  Couple of thoughts...
- Similar to the sd command, the outer edges of the mmc command code should probably be in the main/common
   directory as mmc.c; but for now I pushed it as is.
- I turned on INCLUDE_XMODEM in config.h just so that we can update without pulling the uSD card all the time.
- Should the 'write' command for sd and mmc include a "are you sure?" prompt?  I'm mixed on that one.
   That was optionally covered by the user levels in uMon a while ago, so maybe we just leave it for that
   (making it up to the user).

Hey, this is really shaping up!!!
Good work.  Its all pulled into the master.

> I just want to add that I was able to transfer the uMon image from the
> SD card to the eMMC.  I then removed the SD card and power-cycled the
> BBB, and I was able to boot uMon from the eMMC.
> The sequence steps I took are as follows:
>          sd init
>          mmc init
>          sd read 0x80100000 0 102
>          mmc write 0x80100000 0 102
> The '102' is the number of 512 byte blocks required to transfer the uMon image.
> On Tue, Aug 4, 2015 at 11:03 AM, Jarielle Catbagan
> <jcatbagan93 at> wrote:
>> These series of patches add the "mmc" command which is the interface to the onboard eMMC on the BBB.
>> The "mmc" command is implemented with initialization, reading, and writing functionality.
>> Furthermore, the MMC0 and MMC1 clock enable are moved to initCPUio() in cpuio.c to ensure that the
>> MMC modules are enabled before they are accessed.
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