1 2This is a demo implementation of a Linux command line tool to access 3the U-Boot's environment variables. 4 5For the run-time utiltity configuration uncomment the line 6#define CONFIG_FILE "/etc/fw_env.config" 7in fw_env.h. 8 9For building against older versions of the MTD headers (meaning before 10v2.6.8-rc1) it is required to pass the argument "MTD_VERSION=old" to 11make. 12 13See comments in the fw_env.config file for definitions for the 14particular board. 15 16Configuration can also be done via #defines in the fw_env.h file. The 17following lines are relevant: 18 19#define HAVE_REDUND /* For systems with 2 env sectors */ 20#define DEVICE1_NAME "/dev/mtd1" 21#define DEVICE2_NAME "/dev/mtd2" 22#define DEVICE1_OFFSET 0x0000 23#define ENV1_SIZE 0x4000 24#define DEVICE1_ESIZE 0x4000 25#define DEVICE2_OFFSET 0x0000 26#define ENV2_SIZE 0x4000 27#define DEVICE2_ESIZE 0x4000 28 29Current configuration matches the environment layout of the TRAB 30board. 31 32Un-define HAVE_REDUND, if you want to use the utlities on a system 33that does not have support for redundant environment enabled. 34If HAVE_REDUND is undefined, DEVICE2_NAME is ignored, 35as is ENV2_SIZE and DEVICE2_ESIZE. 36 37The DEVICEx_NAME constants define which MTD character devices are to 38be used to access the environment. 39 40The DEVICEx_OFFSET constants define the environment offset within the 41MTD character device. 42 43ENVx_SIZE defines the size in bytes taken by the environment, which 44may be less then flash sector size, if the environment takes less 45then 1 sector. 46 47DEVICEx_ESIZE defines the size of the first sector in the flash 48partition where the environment resides. 49