This is a demo implementation of a Linux command line tool to accessthe U-Boot's environment variables.For the run-time utiltity configuration uncomment the line#define CONFIG_FILE  "/etc/fw_env.config"in fw_env.h.For building against older versions of the MTD headers (meaning beforev2.6.8-rc1) it is required to pass the argument "MTD_VERSION=old" tomake.See comments in the fw_env.config file for definitions for theparticular board.Configuration can also be done via #defines in the fw_env.h file. Thefollowing lines are relevant:#define HAVE_REDUND	/* For systems with 2 env sectors */#define DEVICE1_NAME	"/dev/mtd1"#define DEVICE2_NAME	"/dev/mtd2"#define DEVICE1_OFFSET    0x0000#define ENV1_SIZE         0x4000#define DEVICE1_ESIZE     0x4000#define DEVICE1_ENVSECTORS     2#define DEVICE2_OFFSET    0x0000#define ENV2_SIZE         0x4000#define DEVICE2_ESIZE     0x4000#define DEVICE2_ENVSECTORS     2Current configuration matches the environment layout of the TRABboard.Un-define HAVE_REDUND, if you want to use the utlities on a systemthat does not have support for redundant environment enabled.If HAVE_REDUND is undefined, DEVICE2_NAME is ignored,as is ENV2_SIZE and DEVICE2_ESIZE.The DEVICEx_NAME constants define which MTD character devices are tobe used to access the environment.The DEVICEx_OFFSET constants define the environment offset within theMTD character device.ENVx_SIZE defines the size in bytes taken by the environment, whichmay be less then flash sector size, if the environment takes lessthen 1 sector.DEVICEx_ESIZE defines the size of the first sector in the flashpartition where the environment resides.DEVICEx_ENVSECTORS defines the number of sectors that may be used forthis environment instance. On NAND this is used to limit the rangewithin which bad blocks are skipped, on NOR it is not used.