[U-Boot] [PATCH] tools/env: document current cross-compilation issues and workaround

[Luca Ceresoli]

Signed-off-by: Luca Ceresoli <luca.ceresoli at comelit.it>
---
Cross-compiling fw_{print,set}env has caused people to waste a lot of time:
 - http://www.mail-archive.com/u-boot@lists.denx.de/msg42317.html
 - http://www.mail-archive.com/u-boot@lists.denx.de/msg39735.html
 - http://www.mail-archive.com/u-boot@lists.denx.de/msg48945.html
 - http://www.mail-archive.com/u-boot@lists.denx.de/msg49057.html
so at least let's have it documented.

 tools/env/README |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/tools/env/README b/tools/env/README
index 91e679a..d5f228f 100644
--- a/tools/env/README
+++ b/tools/env/README
@@ -2,6 +2,12 @@
 This is a demo implementation of a Linux command line tool to access
 the U-Boot's environment variables.
 
+In the current version, there is an issue in cross-compilation.
+In order to cross-compile fw_printenv, run
+    make HOSTCC=<your CC cross-compiler> env
+in the root directory of the U-Boot distribution. For example,
+    make HOSTCC=arm-linux-gcc env
+
 For the run-time utiltity configuration uncomment the line
 #define CONFIG_FILE  "/etc/fw_env.config"
 in fw_env.h.
-- 
1.7.1