X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=tools%2Fenv%2FREADME;h=24e31bc9f808fd6513893b44aefa2d29134e97ef;hb=e9feee63705c1d380e229a381f9a7d696044ff76;hp=2b54adf76bd265d36fa23e12bb4aae90ffcc20c8;hpb=6aff3115b90780933d390d2b471479179927468d;p=u-boot

diff --git a/tools/env/README b/tools/env/README
index 2b54adf76b..24e31bc9f8 100644
--- a/tools/env/README
+++ b/tools/env/README
@@ -2,28 +2,59 @@
 This is a demo implementation of a Linux command line tool to access
 the U-Boot's environment variables.
 
-Configuration is done via #defines in the fw_env.h file. The
+In order to cross-compile fw_printenv, run
+    make CROSS_COMPILE=<your cross-compiler prefix> env
+in the root directory of the U-Boot distribution. For example,
+    make CROSS_COMPILE=arm-linux- env
+
+For the run-time utility 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 before
+v2.6.8-rc1) it is required to pass the argument "MTD_VERSION=old" to
+make.
+
+See comments in the fw_env.config file for definitions for the
+particular board.
+
+Configuration can also be done via #defines in the fw_env.h file. The
 following lines are relevant:
 
 #define HAVE_REDUND	/* For systems with 2 env sectors */
 #define DEVICE1_NAME	"/dev/mtd1"
 #define DEVICE2_NAME	"/dev/mtd2"
-#define ENV1_SIZE	0x4000
-#define DEVICE1_ESIZE	0x4000
-#define ENV2_SIZE	0x4000
-#define DEVICE2_ESIZE	0x4000
-
-Current configuration matches the environment layout of the TRAB
-board.
-
-Un-define HAVE_REDUND, if you want to use the utlities on a system
-that does not have support for redundant environment enabled. The
-DEVICEx_NAME constants define which MTD character device(s) is (are)
-to be used to access the environment. If HAVE_REDUND is undefined,
-DEVICE2_NAME is ignored, as is ENV2_SIZE and DEVICE2_ESIZE. ENVx_SIZE
-defines the size in bytes taken by the environment, which may be less
-then flash sector size, if the environment takes less then 1 sector.
+#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     2
+
+Un-define HAVE_REDUND, if you want to use the utilities on a system
+that 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 to
+be used to access the environment.
+
+The DEVICEx_OFFSET constants define the environment offset within the
+MTD character device.
+
+ENVx_SIZE defines the size in bytes taken by the environment, which
+may be less then flash sector size, if the environment takes less
+then 1 sector.
+
 DEVICEx_ESIZE defines the size of the first sector in the flash
-partition where the environment resides. It is assumed that the
-environment is located in the first ENVx_SIZE bytes of the device
-DEVICEx_NAME.
+partition where the environment resides.
+
+DEVICEx_ENVSECTORS defines the number of sectors that may be used for
+this environment instance. On NAND this is used to limit the range
+within which bad blocks are skipped, on NOR it is not used.
+
+To prevent losing changes to the environment and to prevent confusing the MTD
+drivers, a lock file at /var/lock/fw_printenv.lock is used to serialize access
+to the environment.