Dear Jan Pohanka,
I'm trying to get u-boot 2010.12 working on at91sam9260ek devkit with mmc support. I have read several discussions here and followed the steps described in README.atmel-mci. (my config and board file are below...)
2010.12 is outdated. Use current top of tree. Besides I have a mmc enabled (and working) 9260ek port in my WIP branch that I will post soon.
There are two issues I'm facing.
The first one: When I enable mmc support, the dataflash stops to work. According to info from boot process, dataflash is detected correctly, but no data can be read (environment) or written.
Dataflash and MMC are mutually exclusive on the 9260ek. Only one should be enabled and used.
The second one: fatls command causes u-boot to freeze with following message
You have to remove the CS jumper to the dataflash chip, otherwise you get contention between mmc and dataflash hardware.
Reinhard