Rick, thx a lot for your pdf file. but the information is based on SabreSD board. But i designed my customer board based on SabreAuto board, use eMMC as boot devices. I traced the code, there are different.
The following is my step to build uboot:
1) make mx6q_sabreauto_mfg_config
2) make
build uImage is as below:
1) make imx6_updater_defconfig
2) make uImage.
Howerver, there is not any log output from Uart4, the mfg tool stop on "jumping to OS image".
If I use u-boot-mx6q-sabresd.bin as mfg tool firmware, it can run more step, and UART1 can output many u-boot log.
I don't know why, do you have any idea?