I have an iMX7D Sabre board and I'm trying to get a UHS-I SD card to work. Is this possible? Looking at the Sabre schematic I don't see a 1.8V source anywhere? Are there any steps to take other than enabling uSDHCx_VEND_SPEC.VSELECT? I just finished using the LS1043A that allowed you to set SCFG_SDHCIOVSELCR to enable auto voltage selection.
Am I correct in believing that to support SDR104 BOOT_CFG[3:1] has to be set to 3? Or is that just for bootup?