u-boot/tools/env/fw_env.config

# Configuration file for fw_(printenv/saveenv) utility.
# Up to two entries are valid, in this case the redundant
# environment sector is assumed present.
# Notice, that the "Number of sectors" is ignored on NOR and SPI-dataflash.
# Futhermore, if the Flash sector size is ommitted, this value is assumed to
# be the same as the Environment size, which is valid for NOR and SPI-dataflash

# NOR example
# MTD device name	Device offset	Env. size	Flash sector size	Number of sectors
/dev/mtd1		0x0000		0x4000		0x4000
/dev/mtd2		0x0000		0x4000		0x4000

# MTD SPI-dataflash example
# MTD device name	Device offset	Env. size	Flash sector size	Number of sectors
#/dev/mtd5		0x4200		0x4200
#/dev/mtd6		0x4200		0x4200

# NAND example
#/dev/mtd0		0x4000		0x4000		0x20000			2