And i this helps as it helped me understand part of the process . . .

http://git.denx.de/?p=u-boot.git;a=blob;f=include/configs/am335x_evm.h;hb=HEAD#l57


On Mon, Apr 28, 2014 at 6:09 PM, John Syn <[email protected]> wrote:

>
> From: William Hermans <[email protected]>
> Reply-To: <[email protected]>
> Date: Monday, April 28, 2014 at 3:58 PM
> To: <[email protected]>
> Subject: Re: [beagleboard] Re: Booting Archlinux from microSD (again)
>
> *I cannot even remember why we went down this road. *
>
> Me either. except that the OP was concerned about making hardware
> modifications to his/her board, and by extension having others do the same.
> Something about ARCH Linux not working in this context, when I know that it
> does.
>
> All i really wanted to stress is that reconfiguring the BBB hardware
> should not have to be done.
>
> You are correct. I think I was answering OP's question regarding "booting
> from the SDCard no matter what is on the eMMC”. Perhaps that is why I went
> down this rat hole. Sorry about that.
>
> Regards,
> John
>
>
>
>
> On Mon, Apr 28, 2014 at 3:32 PM, John Syn <[email protected]> wrote:
>
>>
>> From: William Hermans <[email protected]>
>> Reply-To: <[email protected]>
>> Date: Monday, April 28, 2014 at 3:11 PM
>> To: <[email protected]>
>>
>> Subject: Re: [beagleboard] Re: Booting Archlinux from microSD (again)
>>
>> John yeah I can not test that. All I have for a tty into uboot is an
>> MSP430 v1.5  Launchpad, with the MCU pulled to serve as a cheap way to get
>> a console AFTER uEnv.txt has loaded. This has to do with the fact that the
>> Launchpad is 9600 bps only, and from what I can tell uboot is hardwired at
>> 115200 bps until uEnv.txt is read and applied.
>>
>> What I mean all along when I say "boot/booting" is that I pull the kernel
>> from x.y.z location. Which is to say I know that comes from the uSD. As for
>> MLO / uboot ? I really do not know, what would happen if i completely
>> erased the eMMC ?
>>
>> Well, as Robert said, if the eMMC does not contain a MLO with a valid
>> header, the BBB will look for an MLO on the next device in the boot
>> sequence, which in this case is the SDCard.
>>
>> Regards,
>> John
>>
>>
>>
>>
>> On Mon, Apr 28, 2014 at 3:02 PM, William Hermans <[email protected]>wrote:
>>
>>> upset me ? no you did not, but what Robert just said verifies what I've
>>> been saying all along. All you need is a good uEnv.txt.
>>>
>>> I am not an EE by ant stretch of the imagination, but I know I've been
>>> "booting" from uSD since at least June last year. So, when i say "I dont
>>> care about the schematics" I mean that MAYBE the hardware may be wired that
>>> way, but software can and will override( or at least seems this way ).
>>>
>>> End result, no having to pull x.y.z pin low, or whatever. You just use a
>>> config line in uEnv.txt.
>>>
>>>
>>> On Mon, Apr 28, 2014 at 12:40 PM, John Syn <[email protected]> wrote:
>>>
>>>>
>>>> From: Robert Nelson <[email protected]>
>>>> Reply-To: <[email protected]>
>>>> Date: Monday, April 28, 2014 at 12:08 PM
>>>> To: Beagle Board <[email protected]>
>>>>
>>>> Subject: Re: [beagleboard] Re: Booting Archlinux from microSD (again)
>>>>
>>>>
>>>> On Apr 28, 2014 1:28 PM, "John Syn" <[email protected]> wrote:
>>>> >
>>>> >
>>>> > On 4/28/14, 9:58 AM, "Robert Nelson" <[email protected]> wrote:
>>>> >
>>>> > >>
>>>> > >> I didn¹t mean to upset you and I apologize for that. Here is a non
>>>> book,
>>>> > >> hands on test that may help. Change the version of your u-boot on
>>>> your
>>>> > >> SDCard and then reboot and see which version of u-boot is
>>>> displayed on
>>>> > >>the
>>>> > >> debug console.  I¹m hoping that the u-boot version in the boot
>>>> console
>>>> > >>will
>>>> > >> not change or I¹ve got this completely wrong.
>>>> > >
>>>> > >As long as the bootrom finds a valid header in the MLO file, it'll
>>>> > >boot from that device. (the mmc interface wired to the eMMC has
>>>> > >priority over mmc interface wired to the microSD in the bootroom
>>>> > >order).
>>>> > Hi Robert,
>>>> >
>>>> > Thanks for clearing this up. I was beginning to doubt myself. So to be
>>>> > clear, we need to remove the MLO from the eMMC to make the BBB boot
>>>> from
>>>> > the SDCard?
>>>>
>>>> That's one way, a good uEnv.txt is just easier.
>>>>
>>>> Exactly, and now I cannot even remember why we went down this road ;-)
>>>>
>>>> Thanks for all your help.
>>>>
>>>> Regards,
>>>> John
>>>>
>>>> What happens if there is a valid MLO on the eMMC and there is
>>>> > no u-boot on the eMMC?
>>>>
>>>> It should halt saying can't find uboot.img
>>>>
>>>>
>>>>
>>>> >
>>>> > Regards,
>>>> > John
>>>> > >
>>>> > >Regards,
>>>> > >
>>>> > >--
>>>> > >Robert Nelson
>>>> > >http://www.rcn-ee.com/
>>>>
>>>> > >
>>>> > >--
>>>> > >For more options, visit http://beagleboard.org/discuss
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>>>
>>>
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