e-mmc boot error

Hi all

I’m having some trouble getting an e-mmc device to boot my beagleboard. The device is an evaluation board that has a Micron 4GB e-mmc Flash part on it in the shape of a SD card. I formated the card on my Ubuntu laptop and everything mounts correctly on it, but when booting the BB I get a:

Waiting for root device /dev/mmcblk0p2
mmc0: error -110 whilst initialising MMC card

and it just hangs. I’ve done fsck checks on both partitions and they are fine. I know my board works because I have a 1GB SD loaded with the same files that works. I’m using kernel 2.6.28-omap1 and uboot 1.3.3
Any ideas whats going on?



Have you evaluated the differences between e-mmc and regular MMC or
SD? Does this evaluation board have additional power requirements,
extra control signals, or changes in the command set?

It looks like the error is a timeout, likely in mmc_send_op_cond() in
drivers/mmc/core/mmc_ops.c. You could probably add some debug
statements around that to figure out what is going on.

SDHC cards sometimes also have this -110 error.
There is a patch for that in the 2.6.29 kernel.
I suggest to give that one a try (or backport the patch to 2.6.28,
also not difficult).