Booting a Beagle board from an MMC/SD should be easier than what people tell you
At the time of this writing, most documentation that you can find on the web about the Beagle board will tell you that you need to take special preparation steps if you wish to boot your board on an MMC/SD card:
- The card requires a special geometry: 255 heads and 63 sectors per track
- The first partition on the card, with a FAT type, must be marked as bootable
- The X-loader (
MLOfile), must be copied to the first sectors of the first partition. As a consequence, you should copy this file first.
As my colleague Florent Peyraud and TI engineers started to suspect, all this is not always required. I’ve just made tests with my Rev C2 Beagle board:
- I took a brand new MMC/SD card.
fdiskshowed that it had 57 heads and 56 sectors per track.
- I created the partitions again, and didn’t flag the first one as bootable.
- After formatting the first partition in FAT32 format, I first copied the
uImagefiles, and then the
After all this, I had no problem booting my Beagle board on the MMC/SD card. At least with my Rev C2 board, what TI engineers expected was true: the board romcode understood the FAT format, and therefore just needed a file with the
MLO name, whatever its physical location on the card.
Does anyone know whether the requirements used to be true with earlier Beagle board romcode releases, or in special cases?