Add documentation on the latest build environment extentions to
the README file.
diff --git a/README b/README
index e024023..a0949f0 100644
--- a/README
+++ b/README
@@ -2323,6 +2323,26 @@
- "u-boot" is an image in ELF binary format
- "u-boot.srec" is in Motorola S-Record format
+By default the build is performed locally and the objects are saved
+in the source directory. One of the two methods can be used to change
+this behavior and build U-Boot to some external directory:
+
+1. Add O= to the make command line invocations:
+
+ make O=/tmp/build distclean
+ make O=/tmp/build NAME_config
+ make O=/tmp/build all
+
+2. Set environment variable BUILD_DIR to point to the desired location:
+
+ export BUILD_DIR=/tmp/build
+ make distclean
+ make NAME_config
+ make all
+
+Note that the command line "O=" setting overrides the BUILD_DIR environment
+variable.
+
Please be aware that the Makefiles assume you are using GNU make, so
for instance on NetBSD you might need to use "gmake" instead of
@@ -2376,6 +2396,22 @@
CROSS_COMPILE=' ' MAKEALL
+When using the MAKEALL script, the default behaviour is to build U-Boot
+in the source directory. This location can be changed by setting the
+BUILD_DIR environment variable. Also, for each target built, the MAKEALL
+script saves two log files (<target>.ERR and <target>.MAKEALL) in the
+<source dir>/LOG directory. This default location can be changed by
+setting the MAKEALL_LOGDIR environment variable. For example:
+
+ export BUILD_DIR=/tmp/build
+ export MAKEALL_LOGDIR=/tmp/log
+ CROSS_COMPILE=ppc_8xx- MAKEALL
+
+With the above settings build objects are saved in the /tmp/build, log
+files are saved in the /tmp/log and the source tree remains clean during
+the whole build process.
+
+
See also "U-Boot Porting Guide" below.