On Tue, Oct 28, 2014 at 3:29 AM, Karl Karpfen <
karlka...@gmail.com> wrote:
>
> 2014-10-28 5:23 GMT+01:00 Jason Kridner <
jkri...@beagleboard.org>:
>>
>> On Mon, Oct 27, 2014 at 5:16 AM, <
karlka...@gmail.com> wrote:
>>>
>>> Starterware does not support access to eMMC. To do that, you would have
>>> to implement MMC-support to their HSMMCSD-library in order to make MLO able
>>> to boot APPs from there.
>>
>>
>> Have you done anything to confirm what you are saying? It would be helpful
>> to say when you suspect something vs. when you know something.
>
>
> This is confirmed by TI in StarterWare support forum. Google or the search
> function at
http://e2e.ti.com/support/embedded/starterware/f/790.aspx is
> your friend.
You don't need support in the library in order to BOOT. MLO can boot
applications out of eMMC just fine. How do you think we are loading
u-boot?
>
>>
>> Neither the bootloader is in ROM nor the MLO app make any use of
>> Starterware, so if Starterware supports eMMC or not is irrelevant to if you
>> can boot a Starterware application from eMMC using the ROM and MLO. There's
>> no reason you couldn't skip MLO entirely unless your Staterware image is
>> particularly large. If you want to use MLO, again, there's no reason that
>> couldn't target a Starterware application.
>>
>> Also, as far as I know, MMC-support is not required to use an eMMC as it
>> should support one of the other modes.
>
>
> No, that's not correct. The MLO that comes with Starterware
Probably better to use the MLO that is part of mainline u-boot than a
TI fork. The recent primary maintainer of u-boot works for TI and is
pretty good at bringing in support for TI devices.
> and normally is
> used to boot a Starterware-application itself bases on Starterware. So it
> depends on its (not existant) features. One of course can create an MLO as
> only application and try to put all its functionality into that MLO - then
> the CPU will be able to boot the MLO and eMMC support is not required.
Yes, that is part of what I was trying to assert. Sorry to not make
that more clear.
> But
> as soon as an separate APP is requied - e.g. because the available space for
> MLO is not enough - the MLO definitely needs to come with eMMC support.
Mainline MLO has eMMC support. It is only when the StarterWare
application ITSELF needs to access the eMMC that the StarterWare
library needs to include eMMC support.
With regards to accessing the eMMC using the StarterWare library, my
issue was with the term "MMC support". It is still my assertion that
other modes supported by the StarterWare library, like 4-bit SD mode,
should work well with eMMC devices[3], though I haven't confirmed with
the eMMC that is on BeagleBone Black.
The fix supplied in the attached diff (extracted from the forum post)
adds an 8-bit MMC mode, so it doesn't address my assertion.
[3]
http://arasan.com/products/sd-emmc/emmc-4-5-device/
[4]
https://www.linkedin.com/groups/SPI-mode-in-eMMC-Devices-37565.S.77338175