[U-Boot] boot from micro sd

Dear Sir,

We have an i.mx6 board which based on mx6sabresd kit, which u-boot is loaded from USB and working(SD card,e-MMC, Flash, DDR, Ethernet etc) Only the SD card is micro SD 4 bit wide and its card detect pin is also different (CD/DATA3) from origininal kit design. For the small PCB sizes, there is no boot config switches or resistors also. Therefore we will program the fuses to processor to boot from SD card, (or (Q)SPI flash).

I wonder if mx6 boot loader firmware checks for special sd card detect pins and/or if not find a card, does it check CD/DATA3 pins status for u-boot code?

Could Anybody help?

Thanks and best regards.

Mehmet Ali