Using MMC 2Gb - it won't work!


14 posts
by thexeno » Fri Jan 04, 2013 7:04 pm
Hi!
Today I tried to burn the latest Raspbian Wheezy on a different support rather than SD, like I used to.

It won't boot: the green led blink three times, pause, blink three times, pause ecc... I tried to flash it again, but nothing change. Is the MMC type?

I flashed on a Kingston MMC Mobile "Dual-Voltage support", that I used in a nokia 6680 years ago. The memory is working perfectly and it's even faster than SD used before.
I didn't read warnings about using mmc, and there's people that are using mmcs. :evil:

thanks to all!
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by thexeno » Fri Jan 04, 2013 8:18 pm
PS: I know about issue related to start.elf, but it's present on MMC.
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by rpdom » Fri Jan 04, 2013 9:00 pm
I used to use some small (32 and 128MB) MMC cards for some bare metal testing, but they don't seem to work with the more recent firmware. I suspect that support for MMC has been dropped in favour of better SD support as almost all users will have SD cards.
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by thexeno » Sat Jan 05, 2013 1:36 am
And there's nothing official about that?
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by thexeno » Sat Jan 05, 2013 1:33 pm
MMCs became usupported since the firmware do not require the loader.bin and started to use *.elf files? (http://elinux.org/R-Pi_Troubleshooting#Green_LED_blinks_in_a_specific_pattern)

There's a trick to use recent firmwares on this memory? Why these file changes? I didn't found something useful with my friend google :P
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by SimonSmall » Sat Jan 05, 2013 10:05 pm
thexeno: "And there's nothing official about that?"

The requirements clearly state that you need a SD card.

Technical information is hard to find, but I did find (http://wiki.seabright.co.nz/wiki/SdCardProtocol.html) a statement that the initialisation sequences are different. The initialisation is done by the firmware of the GPU, so I guess they have only used the sequence for the SD card. A brief look at Linux information suggests that both MMC and SD cards can be read by Linux, so I guess that you could use your cards in an adapter on a USB port (as storage, not boot). It does seem that the MMC card is physically thicker than the SD card and may not fit in a SD adaptor
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by thexeno » Sun Jan 06, 2013 1:33 am
Cool, thanks a lot. So, itcan works if we change the initialisation part of the firmware. It's possible? Of course XD
But someone know how to do this? To be honest, i don't know even where to start for searching infos about that :?
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by thexeno » Sun Jan 06, 2013 11:47 am
Even some rough indications from where to start doing this. Of course I'm not expecting a full ready prepared answer. No lunch is free ;)
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by thexeno » Sun Jan 13, 2013 2:28 am
@Simon: when you say " The initialisation is done by the firmware of the GPU, so I guess they have only used the sequence for the SD card." is it possible that the sequence of initialization of MMC is still available somewhere? I hope so, it's open source, btw :D
Because in early versions MMC has been supported.
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by ghans » Sun Jan 13, 2013 9:48 am
Nothing what runs on the GPU is open-source.
And as the GPU boots the Pi (bit unusual , true) that includes
the bootloader.


ghans
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by thexeno » Thu Jan 17, 2013 10:16 pm
that's too bad :(
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by ghans » Thu Jan 17, 2013 10:19 pm
Open a issue on github ... perhaps dom has some spare time ...


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by thexeno » Tue Jun 04, 2013 10:22 am
On github Gordon is saying that an MMC should work... I keep searching on it. Maybe I just need to find an old boot sequence with .bin files which the lasts distros doesn't use. I'm wondering if it's possible to use the old boot system with the latest distro.
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by nox86 » Fri Jun 07, 2013 8:16 pm
the same problem with mmc (
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