diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 753be9f..5588e4b 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,5 +1,11 @@
 2018-12-06  Andrew Burgess  <andrew.burgess@embecosm.com>
 
+	* configure.ac (enable-cgen-maint): Support passing path to cgen
+	source tree.
+	* configure: Regenerate.
+
+2018-12-06  Andrew Burgess  <andrew.burgess@embecosm.com>
+
 	* disassembler.c (disassemble_init_for_target): Add RISC-V
 	initialisation.
 	* riscv-dis.c (riscv_symbol_is_valid): New function.
diff --git a/opcodes/configure b/opcodes/configure
index 389e551..eb74324 100755
--- a/opcodes/configure
+++ b/opcodes/configure
@@ -12574,11 +12574,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
 	cgen_maint=yes
-	cgendir=${cgen_maint}/lib/cgen
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  as_fn_error $? "${enableval} doesn't look like a cgen source tree" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/opcodes/configure.ac b/opcodes/configure.ac
index 4c36983..7384684 100644
--- a/opcodes/configure.ac
+++ b/opcodes/configure.ac
@@ -109,11 +109,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
 	cgen_maint=yes
-	cgendir=${cgen_maint}/lib/cgen
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  AC_MSG_ERROR(${enableval} doesn't look like a cgen source tree)
+        fi
 	;;
 esac])dnl
 AM_CONDITIONAL(CGEN_MAINT, test x${cgen_maint} = xyes)
diff --git a/sim/ChangeLog b/sim/ChangeLog
index 8fdef08..efd1f88 100644
--- a/sim/ChangeLog
+++ b/sim/ChangeLog
@@ -1,3 +1,15 @@
+2018-12-06  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* common/acinclude.m4 (enable-cgen-maint): Support passing path to
+	cgen source tree.
+	* cris/configure: Regenerate.
+	* frv/configure: Regenerate.
+	* iq2000/configure: Regenerate.
+	* lm32/configure: Regenerate.
+	* m32r/configure: Regenerate.
+	* or1k/configure: Regenerate.
+	* sh64/configure: Regenerate.
+
 2018-10-05  Stafford Horne  <shorne@gmail.com>
 
 	* or1k/cpu.h: Regenerate.
diff --git a/sim/common/acinclude.m4 b/sim/common/acinclude.m4
index abc15a9..71a8841 100644
--- a/sim/common/acinclude.m4
+++ b/sim/common/acinclude.m4
@@ -851,11 +851,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${cgen_maint}/lib/cgen
-	cgen=guile
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
+	cgen_maint=yes
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  AC_MSG_ERROR(${enableval} doesn't look like a cgen source tree)
+        fi
 	;;
 esac])dnl
 dnl AM_CONDITIONAL(CGEN_MAINT, test x${cgen_maint} != xno)
diff --git a/sim/cris/configure b/sim/cris/configure
index 8ef9155..76f3c28 100755
--- a/sim/cris/configure
+++ b/sim/cris/configure
@@ -13912,11 +13912,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${cgen_maint}/lib/cgen
-	cgen=guile
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
+	cgen_maint=yes
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  as_fn_error $? "${enableval} doesn't look like a cgen source tree" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/frv/configure b/sim/frv/configure
index 934afd0..eeffc95 100755
--- a/sim/frv/configure
+++ b/sim/frv/configure
@@ -13681,11 +13681,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${cgen_maint}/lib/cgen
-	cgen=guile
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
+	cgen_maint=yes
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  as_fn_error $? "${enableval} doesn't look like a cgen source tree" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/iq2000/configure b/sim/iq2000/configure
index 9486ef4..92ed9c8 100755
--- a/sim/iq2000/configure
+++ b/sim/iq2000/configure
@@ -13678,11 +13678,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${cgen_maint}/lib/cgen
-	cgen=guile
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
+	cgen_maint=yes
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  as_fn_error $? "${enableval} doesn't look like a cgen source tree" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/lm32/configure b/sim/lm32/configure
index 9624db3..748266d 100755
--- a/sim/lm32/configure
+++ b/sim/lm32/configure
@@ -13678,11 +13678,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${cgen_maint}/lib/cgen
-	cgen=guile
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
+	cgen_maint=yes
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  as_fn_error $? "${enableval} doesn't look like a cgen source tree" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/m32r/configure b/sim/m32r/configure
index 43c25a6..8ce674c 100755
--- a/sim/m32r/configure
+++ b/sim/m32r/configure
@@ -13680,11 +13680,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${cgen_maint}/lib/cgen
-	cgen=guile
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
+	cgen_maint=yes
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  as_fn_error $? "${enableval} doesn't look like a cgen source tree" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/or1k/configure b/sim/or1k/configure
index 93aeb8f..1386585 100755
--- a/sim/or1k/configure
+++ b/sim/or1k/configure
@@ -13788,11 +13788,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${cgen_maint}/lib/cgen
-	cgen=guile
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
+	cgen_maint=yes
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  as_fn_error $? "${enableval} doesn't look like a cgen source tree" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/sh64/configure b/sim/sh64/configure
index 17a4833..b02f835 100755
--- a/sim/sh64/configure
+++ b/sim/sh64/configure
@@ -13678,11 +13678,17 @@
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${cgen_maint}/lib/cgen
-	cgen=guile
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
+	cgen_maint=yes
+        if test -r ${enableval}/iformat.scm; then
+          # This looks like a cgen source tree.
+	  cgendir=${enableval}
+        else
+	  as_fn_error $? "${enableval} doesn't look like a cgen source tree" "$LINENO" 5
+        fi
 	;;
 esac
 fi