Boot from emmc

Hi Anson,

did you get an answer for your question?

If you did what was it? it's not really clear what is possible or not, and we would also like to boot from MMC0 port so that we don't block the GPMC port.

Thomas

There are some restrictions to use an eMMC device on MMC0 port:  The next version of the TRM will include the following details for that section:

Each interface has booting restrictions on which type of memory it supports: -
• MMC0 supports booting from the MMC/SD card cage and also supports booting from
eMMC/eSD/managed NAND memory devices with less than 4GB capacity.
• MMC1 supports booting from eMMC/eSD/managed NAND memory device with 4GB capacity or
greater.
The restriction is a result of many eMMC devices not being compliant with the eMMC v4.41 specification.
If you have the need to boot from two different card cages, many MMC/SD cards will boot from MMC1, but
for maximum compatibility only MMC0 should be used to boot from the card cage. Similarly for maximum
compatibility, booting from eMMC/eSD/managed NAND should only be performed on MMC1.
Note that the above restrictions only apply to booting from each port. Drivers can be written for either port
to support any desired interface.
Note:
• The ROM Code does not handle the card detection feature on card cage.
• If MMC1 is used the GPMC interface is not usable, due to pin muxing options.
• MMC1 supports sector mode without querying the card.

Regards,

James

Thank you very much for the detailed and precise answer.

It's unfortunately not the answer I was looking for, because this means that we can either boot from MMC0 eMMC and not use the GPMC or we can use the GPMC and not boot from MMC0 eMMC. But that is not your fault.

I'll have to see what that means for the overall design