Merge branch 'master' of git://git.denx.de/u-boot-usb

[karo-tx-uboot.git] / tools / env / README

diff --git a/tools/env/README b/tools/env/README
index f8a644e0c2b1c76de58b26742cba9f3fe320b0ad..24e31bc9f808fd6513893b44aefa2d29134e97ef 100644 (file)
--- a/tools/env/README
+++ b/tools/env/README
@@ -2,7 +2,12 @@
 This is a demo implementation of a Linux command line tool to access
 the U-Boot's environment variables.
 
-For the run-time utiltity configuration uncomment the line
+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.
 
@@ -22,14 +27,13 @@ following lines are relevant:
 #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
 
-Current configuration matches the environment layout of the TRAB
-board.
-
-Un-define HAVE_REDUND, if you want to use the utlities on a system
+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.
@@ -46,3 +50,11 @@ then 1 sector.
 
 DEVICEx_ESIZE defines the size of the first sector in the flash
 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.