--- a/CHANGES	Wed Feb 13 05:20:01 2019 +0000
+++ b/CHANGES	Wed Feb 13 06:02:58 2019 +0000
@@ -30,7 +30,8 @@
   details.
 
 * Compilation and installation: the Makefile hierarchy has been reworked to
-  allow CC= and CFLAGS= to be overridden from the top for the entire package.
+  allow CC= and CFLAGS= to be overridden from the top for the entire package,
+  and also to allow installation in a staging location - see INSTALL.
 
 Changes from fc-host-tools-r9 to fc-host-tools-r9a:
 

--- a/INSTALL	Wed Feb 13 05:20:01 2019 +0000
+++ b/INSTALL	Wed Feb 13 06:02:58 2019 +0000
@@ -56,6 +56,15 @@
 run; this utility has now been moved to a separate freecalypso-ui-dev
 repository and is no longer a part of the core FC host tools package.
 
+CC= and CFLAGS= selection
+=========================
+
+Our Makefile hierarchy is set up to build with CC=gcc and CFLAGS=-O2 by default.
+If you need to change either or both of these selections, you can do it by
+adding CC= and/or CFLAGS= on the make invokation line, for example:
+
+make CC=mygcc CFLAGS="-g -O2 -whatever-options"
+
 libserial and Linux specifics
 =============================
 
@@ -121,3 +130,25 @@
 
 Run 'make all' in target-utils to build some additional target code pieces that
 are needed only for development and only very rarely.
+
+Staged installs
+===============
+
+As already explained above, our FC host tools need to be installed under
+/opt/freecalypso on your system in order to function correctly, and this runtime
+location is not changeable.  However, some users have requested an ability to
+do a staged install: have the 'make install' operation install the finished
+tree of files in some staging location, with the expectation that it will be
+subsequently moved to /opt/freecalypso by some other mechanism.  One use case
+that has been presented to us was automated building of binary distribution
+packages on a build host where writing to /opt/freecalypso is not allowed.
+
+If you need to make a staged install of this sort, you can do it like this:
+
+make install INSTALL_PREFIX=/home/me/my-fc-staging-area
+
+Please note that this INSTALL_PREFIX= scheme changes *only* the location where
+'make install' will deposit the installable files; it does NOT change the
+location where our programs will look for other programs and helper files: the
+latter location is hard-coded as /opt/freecalypso is bazillion places throughout
+our code base.