I put u-boot, kernel and rootfs into the same SD. Kernel boots up, but continue waiting for rootfs, which is mmcblk1p1.
What Linux package did you download?
Did you set the u-boot environment variables as specified in section 8.2 of i.MX_6_SABRE-SD_Linux_User's_Guide (for Linux 3.10.17) or section 9.2 of i.MX_6Dual6Quad_SABRE-SD_Linux_User's_Guide (for Linux 3.0.35)?
Could you provide the serial output while the board is booting up and your u-boot environment variables?
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