U-Boot not seeing eMMC on i.MX6

[simonr99]

I've (finally) got Mfgtool to flash my U-Boot/Kernel/FS to eMMC on my Hummingboard.

Once flashed, my U-Boot boots from eMMC, but then fails to boot my Kernel. It looks like U-boot can't see the eMMC ('mmc list' only lists the SD card, not eMMC).

How should I configure U-Boot so that it can see the eMMC partitions?

Yocto Fido

U-Boot 2013.10-rc4

Thanks

Simon

[shubhamsaxena]

After going through the code and probing emmc lines, following are the observations:

=> After power cycle the board, u-boot comes up from emmc so it means ROM code is able to access or communicate with emmc. Also after booting in kernel (from sd card) we were able to create partitions, load them and copy files to it.

=> We put some debugging prints (file attached) and observer that it is failing after third attempt to CMD1 due to timeout

=> Probing the lines showed that clock and command are being sent from processor but no data is received from emmc.

eMMC version: 5.0

Manufacturer: Kingston

Part number: EMMC04G-M627-Z02U

Please let us know if we any specific change is required for this eMMC in u-boot-imx 2015.

[shubhamsaxena · Accepted solution]

Following patch resolved my issue

https://lists.denx.de/pipermail/u-boot/2015-March/209535.html 

Thank you!

[shubhamsaxena]

hi

I am facing same issue. After u-boot comes up, its showing two mmc devices but fails to access emmc.

Following is the scenario:

=> SD card is having environment vairables and u-boot is in emmc

=> After powering on the board u-boot comes up

=> After stopping at u-boot, mmc list command shows FSL_SDHC 0 and 1

=> mmcinfo shows correct information for SD card

=> then we change the "mmc dev 1" (it switches to emmc base address, as I have put a debug print to confirm)

=> in this case if we give mmcinfo command it shows sd card information instead of emmc

I have attached the logs for reference.