--- a/configure.sh	Sun Jul 22 19:10:47 2018 +0000
+++ b/configure.sh	Tue Jul 24 02:37:02 2018 +0000
@@ -54,9 +54,6 @@
 
 . "targets/$TARGET.conf"
 
-BUILD_DIR="build-$TARGET-$CONFIG"
-USE_STR2IND=0
-
 # settings derived from the target-defined DSP version
 
 case "$DSP" in
@@ -104,6 +101,9 @@
 ALLOW_CSIM_GSM=1
 SERIAL_DYNAMIC_SWITCH=0
 TR_BAUD_CONFIG=TR_BAUD_115200
+USE_STR2IND=0
+
+SUFFIX=
 
 # allow the user to override these defaults
 
@@ -115,6 +115,8 @@
 	shift
 done
 
+BUILD_DIR="build-$TARGET-$CONFIG$SUFFIX"
+
 echo "Building configuration $CONFIG for target $TARGET in $BUILD_DIR"
 
 if [ "$clean_flag" = 1 ]
@@ -237,7 +239,7 @@
 
 # generate the top level Makefile!
 
-helpers/makeline def CONFIG_NAME $CONFIG > $BUILD_DIR/Makefile
+helpers/makeline def CONFIG_NAME "$CONFIG$SUFFIX" > $BUILD_DIR/Makefile
 echo >> $BUILD_DIR/Makefile
 helpers/makeline def SUBDIR $SUBDIR >> $BUILD_DIR/Makefile
 echo >> $BUILD_DIR/Makefile

--- a/doc/Compiling	Sun Jul 22 19:10:47 2018 +0000
+++ b/doc/Compiling	Tue Jul 24 02:37:02 2018 +0000
@@ -59,11 +59,15 @@
 a particular configuration, run a command like this from the top level of the
 fc-magnetite tree:
 
-./configure.sh gtamodem l1reconst
+./configure.sh fcdev3b hybrid
 
-The first argument to the configure.sh script selects the target, and the second
-argument selects the configuration.  As of this writing, the following targets
-are supported:
+The first required argument to the configure.sh script selects the target, the
+second required argument selects the build configuration recipe, and any further
+arguments beyond these two (optional) allow changing various configurable
+settings that aren't strictly fixed by the hardware target or by the build
+configuration recipe.
+
+As of this writing, the following hardware targets are supported:
 
 c11x		Motorola C11x/12x
 c139		Motorola C139/140
@@ -75,11 +79,20 @@
 For the available configurations (the second required argument to the configure
 script), look in the configs directory and read the various write-ups under doc.
 
-Each configuration is built in its own directory; by default the build directory
-is named build-$TARGET-$CONFIG, i.e., for the example configure.sh line above,
-the resulting build directory will be build-gtamodem-l1reconst.  You can change
-the name of this directory by appending a BUILD_DIR=dir argument to the
-./configure.sh line after the two required arguments.
+Each configuration is built in its own directory; the name of this build
+directory takes the form of build-$TARGET-$CONFIG$SUFFIX, i.e., for the example
+configure.sh line above, the resulting build directory will be named
+build-fcdev3b-hybrid.  The $SUFFIX part is empty by default, but can be set on
+the command line in order to distinguish non-standard builds that had some
+tunable settings changed to values other than the default.  For example, if you
+are building the hybrid configuration for the fcdev3b target as above, but you
+need to disable MELODY_E2, you could run the configure script as follows:
+
+./configure.sh fcdev3b hybrid MELODY_E2=0 SUFFIX=-noe2
+
+The build directory would then become build-fcdev3b-hybrid-noe2, and the
+specified suffix will also be included in the firmware version ID string that
+gets compiled into the image.
 
 To actually compile the firmware, cd into the created build directory and run
 make there.  Unfortunately the use of TI's proprietary compiler via Wine makes