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-rw-r--r--tools/env/README43
1 files changed, 29 insertions, 14 deletions
diff --git a/tools/env/README b/tools/env/README
index 2b54adf..d8386f7 100644
--- a/tools/env/README
+++ b/tools/env/README
@@ -2,28 +2,43 @@
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
+For the run-time utiltity configuration uncomment the line
+#define CONFIG_FILE "/etc/fw_env.config"
+in fw_env.h.
+
+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
+#define DEVICE1_OFFSET 0x0000
+#define ENV1_SIZE 0x4000
+#define DEVICE1_ESIZE 0x4000
+#define DEVICE2_OFFSET 0x0000
+#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.
+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.