How do I boot [embedded] linux from sd card? [migrated]

view story

http://stackoverflow.com – I am hacking together a quick embedded linux system on a DM816x evm board. Previously I have been using TFTP and NFS to load my kernel and root filesystem to the board. I am now trying to switch over to loading everything from an SD card. I have my card partitioned such that uBoot and my kernel image are in one partition, and my rootFS in another partition. At power-on, Uboot starts correctly and successfully launches the kernel. However, the kernel is unable to mount the root file system. It appears that it doesn't recognize any SD (mmc) cards. It gives this error message. VFS: Cannot ope (HowTos)