I am trying to boot u-boot from an SD card on an i.MX6 custom board and am having some difficulties.
I have used a JTAG emulator to load u-boot into DDR manually and run it. So I've ironed out DDR timing issues and basic board operation. I have validated u-boot runs and successfully gets to the command prompt. From there I have validated the MMC device is accessible and I can load the kernel binary into memory from the SD card. So I know the interface is working properly, but I cannot seem to boot from the SD card.
I have also validated with an oscilloscope that, on power up, clocks are going to the SD card.
From my reading I believe that the u-boot.imx image should be placed at offset 1024 on the SD card
The specified item was not found.
I have tried various ways to program the binary to the SD card, but have been unsuccessful in booting the board from SD:
$ sudo dd if=u-boot.imx of=/dev/sdb bs=1k seek=1
$ sudo dd if=u-boot.imx of=/dev/sdb bs=512 seek=2
So I have a few questions:
1. What address does the i.MX6 boot ROM read from on power-up when it's looking for the DCD table in the u-boot.imx image?
2. What data is the boot ROM looking for?
3. How do I troubleshoot this further?
In case of relevance, my i.MX6 chip is: MCIMX6Q6AVT10AD SBFV1535 5N55D KOREA D1FVSBF