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IMX6Q Custom U-Boot Help

Question asked by Kyle Cassar on Apr 30, 2019
Latest reply on May 3, 2019 by Kyle Cassar



We are currently trying to boot a custom board by editing i.MX6Q mx6sabresd files.


On our board we have an eMMC chip in SD port 3 and a microSD in SD port 4.


We would like to boot from microSD is slot 4.


What files do we need to edit to enable this to happen?


Our boot DIP switches are set to the correct port, however through the serial terminal, all we are seeing is;

U-Boot SPL 2018.11+fslc+g6e25ce6f3c (Apr 30 2019 - 11:10:01 +0100)
Trying to boot from MMC1


We are building using Yocto and are currently building u-boot manually from within Yocto to make use of our own ported files (files ported from mx6sabresd):


In /board/hgldynamics/mx6dragonfly/mx6dragonfly.c we've attempted to modify the uSDHC pads and related functions appropriately to support or custom board and in /include/configs/mx6dragonfly.h we've set to CONFIG_SYS_MMC_ENV_DEV to what we think is the correct value to select the appropriate port. We have also customised the DCD tables in  /board/hgldynamics/mx6dragonfly/mx6dragonfly.c to match our RAM configuration (or at least we think so).


We've added the appropriate entries to:


We can build a vanilla unmodified mx6sabresd u-boot, kernel and filesystem and these work on our freescale sabresd dev board fine.


Any help would be greatly appreciated.