Thanks to some help from TI, we've finally gotten our MMC device recognized on our custom board and we were able to lay down a partition table and format the filesystems. Here's what we have now:
Disk /dev/mmcblk0: 3867 MB, 3867148288 bytes
4 heads, 16 sectors/track, 118016 cylinders
Units = cylinders of 64 * 512 = 32768 bytes
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 63 368 9792 c Win95 FAT32 (LBA)
/dev/mmcblk0p2 369 62869 2000032 83 Linux
The FAT32 filesystem was formatted with busybox's mkfs.vfat and is able to be mounted and have files written into it. Because we're not yet booting from MMC but instead using a ramdisk with pretty limited capabilities, we instead booted into u-boot and loaded up the partition using:
nfs 0x89000000 192.168.0.1:/home/images/MLO
fatwrite mmc 1:1 0x89000000 MLO 0x${filesize}
nfs 0x89000000 192.168.0.1:/home/images/u-boot.img
fatwrite mmc 1:1 0x89000000 u-boot.img 0x{filesize}
nfs 0x89000000 192.168.0.1:/home/images/uImage
fatwrite mmc 1:1 0x89000000 uImage 0x{filesize}
And we have verified via 'fatls' that the files are loaded into the system and are the correct size. We have not yet loaded a root filesystem into the 2nd partition.
However, when we power up the board, we just get the CCCCC across the terminal that implies that it can't find anything to boot.
We've checked our SYSBOOT pins and verified that MMC1 is in our boot order, and we've even hooked up a debugger and verified that the sysboot pins read as 0x1C, which is what we set them to. What are we missing?
We've also tried RAW mode where the MLO is loaded directly into the memory card, and this seems to work, but we're not sure if we want to use it in production.
