diff --git a/opcodes/configure b/opcodes/configure
index 389e5513cf..eb74324ca8 100755
--- a/opcodes/configure
+++ b/opcodes/configure
@@ -12574,11 +12574,17 @@ if test "${enable_cgen_maint+set}" = set; then :
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
 	cgen_maint=yes
-	cgendir=${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" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/opcodes/configure.ac b/opcodes/configure.ac
index 4c3698356b..7384684bc0 100644
--- a/opcodes/configure.ac
+++ b/opcodes/configure.ac
@@ -109,11 +109,17 @@ AC_ARG_ENABLE(cgen-maint,
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
+	# Argument is a directory where cgen can be found.  In some
+	# future world cgen could be installable, but right now this
+	# is not the case.  Instead we assume the directory is a path
+	# to the cgen source tree.
 	cgen_maint=yes
-	cgendir=${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/common/acinclude.m4 b/sim/common/acinclude.m4
index abc15a93ac..71a8841ab0 100644
--- a/sim/common/acinclude.m4
+++ b/sim/common/acinclude.m4
@@ -851,11 +851,17 @@ AC_ARG_ENABLE(cgen-maint,
   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 8ef9155d82..76f3c284e0 100755
--- a/sim/cris/configure
+++ b/sim/cris/configure
@@ -13912,11 +13912,17 @@ if test "${enable_cgen_maint+set}" = set; then :
   yes)	cgen_maint=yes ;;
   no)	cgen_maint=no ;;
   *)
-	# argument is cgen install directory (not implemented yet).
-	# Having a `share' directory might be more appropriate for the .scm,
-	# .cpu, etc. files.
-	cgendir=${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" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/frv/configure b/sim/frv/configure
index 934afd06ca..eeffc95c75 100755
--- a/sim/frv/configure
+++ b/sim/frv/configure
@@ -13681,11 +13681,17 @@ if test "${enable_cgen_maint+set}" = set; then :
   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" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/iq2000/configure b/sim/iq2000/configure
index 9486ef4a3d..92ed9c8b39 100755
--- a/sim/iq2000/configure
+++ b/sim/iq2000/configure
@@ -13678,11 +13678,17 @@ if test "${enable_cgen_maint+set}" = set; then :
   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" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/lm32/configure b/sim/lm32/configure
index 9624db3d83..748266d2e0 100755
--- a/sim/lm32/configure
+++ b/sim/lm32/configure
@@ -13678,11 +13678,17 @@ if test "${enable_cgen_maint+set}" = set; then :
   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" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/m32r/configure b/sim/m32r/configure
index 43c25a621f..8ce674c0e1 100755
--- a/sim/m32r/configure
+++ b/sim/m32r/configure
@@ -13680,11 +13680,17 @@ if test "${enable_cgen_maint+set}" = set; then :
   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" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/or1k/configure b/sim/or1k/configure
index 93aeb8f50d..1386585654 100755
--- a/sim/or1k/configure
+++ b/sim/or1k/configure
@@ -13788,11 +13788,17 @@ if test "${enable_cgen_maint+set}" = set; then :
   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" "$LINENO" 5
+        fi
 	;;
 esac
 fi
diff --git a/sim/sh64/configure b/sim/sh64/configure
index 17a483329f..b02f835518 100755
--- a/sim/sh64/configure
+++ b/sim/sh64/configure
@@ -13678,11 +13678,17 @@ if test "${enable_cgen_maint+set}" = set; then :
   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
