We have some custom hardware which has a 4-bit wide MicroSD card instead of an 8-bit wide SD card. I can build an Imx28-EVK image (core-image-lsb-dev) and have it boot up fine on the imx28-evk hardware.
I'm using the 3.12 kernel provided by linux-fslc
When I change to our custom hardware I change the .dts file to reflect the 4-bit interface instead,
pinctrl-0 = <&mmc0_4bit_pins_a
bus-width = <4>;
The hardware is connected correctly for this pinout.
Now when I power up the card, u-boot loads fine but it hangs at this point:
Waiting for root device /dev/mmcblk0p3...
Looking at the partitions from my Ubuntu machine, I can see that the rootfs is indeed located at /dev/mmcblk0p3, but it just doesn't seem to be loading.
I found this thread, but it doesn't help me https://community.freescale.com/thread/306904
I'm not experienced with embedded linux systems, or yocto, or u-boot command line so if the answer is "all you need to do is modify u-boot" I'm going to need a little more guidance than that. I've attached the output of the serial console on boot if that helps?
Edit: I should also say that I'm not ruling out a hardware issue, it could be that everything is hunky dory (dora) and the sd card is browning out, I will investigate this in the meantime.
Original Attachment has been moved to: boot.txt.zip