u-boot/tools/env/fw_env.config

# Configuration file for fw_(printenv/saveenv) utility.
# Up to two entries are valid, in this case the redundand
# environment sector is assumed present.

# MTD device name	Device offset	Env. size	Flash sector size
/dev/mtd1		0x0000		0x4000		0x4000
/dev/mtd2		0x0000		0x4000		0x4000