Enable runtime loading of dynamic library with --extlib

5 files changed, 160 insertions, 158 deletions

diff --git a/config.h.in b/config.h.in
index 9272c1b..4ea8c5e 100644
--- a/config.h.in
+++ b/config.h.in
@@ -46,7 +46,7 @@
 #undef SOFTFLOAT_ENABLED
 
 /* Define if subproject MCPPBS_SPROJ_NORM is enabled */
-#undef SOFTFLOAT_RISCV_ENABLED
+#undef SPIKE_ENABLED
 
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
diff --git a/configure b/configure
index cab6739..4a1bf3d 100755
--- a/configure
+++ b/configure
@@ -1,11 +1,13 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for RISC-V ISA Simulator ?.
+# Generated by GNU Autoconf 2.68 for RISC-V ISA Simulator ?.
 #
 # Report bugs to <Andrew Waterman>.
 #
 #
-# Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
+# Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
+# 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software
+# Foundation, Inc.
 #
 #
 # This configure script is free software; the Free Software Foundation
@@ -134,31 +136,6 @@ export LANGUAGE
 # CDPATH.
 (unset CDPATH) >/dev/null 2>&1 && unset CDPATH
 
-# Use a proper internal environment variable to ensure we don't fall
-  # into an infinite loop, continuously re-executing ourselves.
-  if test x"${_as_can_reexec}" != xno && test "x$CONFIG_SHELL" != x; then
-    _as_can_reexec=no; export _as_can_reexec;
-    # We cannot yet assume a decent shell, so we have to provide a
-# neutralization value for shells without unset; and this also
-# works around shells that cannot unset nonexistent variables.
-# Preserve -v and -x to the replacement shell.
-BASH_ENV=/dev/null
-ENV=/dev/null
-(unset BASH_ENV) >/dev/null 2>&1 && unset BASH_ENV ENV
-case $- in # ((((
-  *v*x* | *x*v* ) as_opts=-vx ;;
-  *v* ) as_opts=-v ;;
-  *x* ) as_opts=-x ;;
-  * ) as_opts= ;;
-esac
-exec $CONFIG_SHELL $as_opts "$as_myself" ${1+"$@"}
-# Admittedly, this is quite paranoid, since all the known shells bail
-# out after a failed `exec'.
-$as_echo "$0: could not re-execute with $CONFIG_SHELL" >&2
-as_fn_exit 255
-  fi
-  # We don't want this to propagate to other subprocesses.
-          { _as_can_reexec=; unset _as_can_reexec;}
 if test "x$CONFIG_SHELL" = x; then
   as_bourne_compatible="if test -n \"\${ZSH_VERSION+set}\" && (emulate sh) >/dev/null 2>&1; then :
   emulate sh
@@ -192,8 +169,7 @@ if ( set x; as_fn_ret_success y && test x = \"\$1\" ); then :
 else
   exitcode=1; echo positional parameters were not saved.
 fi
-test x\$exitcode = x0 || exit 1
-test -x / || exit 1"
+test x\$exitcode = x0 || exit 1"
   as_suggested="  as_lineno_1=";as_suggested=$as_suggested$LINENO;as_suggested=$as_suggested" as_lineno_1a=\$LINENO
   as_lineno_2=";as_suggested=$as_suggested$LINENO;as_suggested=$as_suggested" as_lineno_2a=\$LINENO
   eval 'test \"x\$as_lineno_1'\$as_run'\" != \"x\$as_lineno_2'\$as_run'\" &&
@@ -238,25 +214,21 @@ IFS=$as_save_IFS
 
 
       if test "x$CONFIG_SHELL" != x; then :
-  export CONFIG_SHELL
-             # We cannot yet assume a decent shell, so we have to provide a
-# neutralization value for shells without unset; and this also
-# works around shells that cannot unset nonexistent variables.
-# Preserve -v and -x to the replacement shell.
-BASH_ENV=/dev/null
-ENV=/dev/null
-(unset BASH_ENV) >/dev/null 2>&1 && unset BASH_ENV ENV
-case $- in # ((((
-  *v*x* | *x*v* ) as_opts=-vx ;;
-  *v* ) as_opts=-v ;;
-  *x* ) as_opts=-x ;;
-  * ) as_opts= ;;
-esac
-exec $CONFIG_SHELL $as_opts "$as_myself" ${1+"$@"}
-# Admittedly, this is quite paranoid, since all the known shells bail
-# out after a failed `exec'.
-$as_echo "$0: could not re-execute with $CONFIG_SHELL" >&2
-exit 255
+  # We cannot yet assume a decent shell, so we have to provide a
+	# neutralization value for shells without unset; and this also
+	# works around shells that cannot unset nonexistent variables.
+	# Preserve -v and -x to the replacement shell.
+	BASH_ENV=/dev/null
+	ENV=/dev/null
+	(unset BASH_ENV) >/dev/null 2>&1 && unset BASH_ENV ENV
+	export CONFIG_SHELL
+	case $- in # ((((
+	  *v*x* | *x*v* ) as_opts=-vx ;;
+	  *v* ) as_opts=-v ;;
+	  *x* ) as_opts=-x ;;
+	  * ) as_opts= ;;
+	esac
+	exec "$CONFIG_SHELL" $as_opts "$as_myself" ${1+"$@"}
 fi
 
     if test x$as_have_required = xno; then :
@@ -359,14 +331,6 @@ $as_echo X"$as_dir" |
 
 
 } # as_fn_mkdir_p
-
-# as_fn_executable_p FILE
-# -----------------------
-# Test if FILE is an executable regular file.
-as_fn_executable_p ()
-{
-  test -f "$1" && test -x "$1"
-} # as_fn_executable_p
 # as_fn_append VAR VALUE
 # ----------------------
 # Append the text in VALUE to the end of the definition contained in VAR. Take
@@ -488,10 +452,6 @@ as_cr_alnum=$as_cr_Letters$as_cr_digits
   chmod +x "$as_me.lineno" ||
     { $as_echo "$as_me: error: cannot create $as_me.lineno; rerun with a POSIX shell" >&2; as_fn_exit 1; }
 
-  # If we had to re-execute with $CONFIG_SHELL, we're ensured to have
-  # already done that, so ensure we don't try to do so again and fall
-  # in an infinite loop.  This has already happened in practice.
-  _as_can_reexec=no; export _as_can_reexec
   # Don't try to exec as it changes $[0], causing all sort of problems
   # (the dirname of $[0] is not the place where we might find the
   # original and so on.  Autoconf is especially sensitive to this).
@@ -526,16 +486,16 @@ if (echo >conf$$.file) 2>/dev/null; then
     # ... but there are two gotchas:
     # 1) On MSYS, both `ln -s file dir' and `ln file dir' fail.
     # 2) DJGPP < 2.04 has no symlinks; `ln -s' creates a wrapper executable.
-    # In both cases, we have to default to `cp -pR'.
+    # In both cases, we have to default to `cp -p'.
     ln -s conf$$.file conf$$.dir 2>/dev/null && test ! -f conf$$.exe ||
-      as_ln_s='cp -pR'
+      as_ln_s='cp -p'
   elif ln conf$$.file conf$$ 2>/dev/null; then
     as_ln_s=ln
   else
-    as_ln_s='cp -pR'
+    as_ln_s='cp -p'
   fi
 else
-  as_ln_s='cp -pR'
+  as_ln_s='cp -p'
 fi
 rm -f conf$$ conf$$.exe conf$$.dir/conf$$.file conf$$.file
 rmdir conf$$.dir 2>/dev/null
@@ -547,8 +507,28 @@ else
   as_mkdir_p=false
 fi
 
-as_test_x='test -x'
-as_executable_p=as_fn_executable_p
+if test -x / >/dev/null 2>&1; then
+  as_test_x='test -x'
+else
+  if ls -dL / >/dev/null 2>&1; then
+    as_ls_L_option=L
+  else
+    as_ls_L_option=
+  fi
+  as_test_x='
+    eval sh -c '\''
+      if test -d "$1"; then
+	test -d "$1/.";
+      else
+	case $1 in #(
+	-*)set "./$1";;
+	esac;
+	case `ls -ld'$as_ls_L_option' "$1" 2>/dev/null` in #((
+	???[sx]*):;;*)false;;esac;fi
+    '\'' sh
+  '
+fi
+as_executable_p=$as_test_x
 
 # Sed expression to map a string onto a valid CPP name.
 as_tr_cpp="eval sed 'y%*$as_cr_letters%P$as_cr_LETTERS%;s%[^_$as_cr_alnum]%_%g'"
@@ -1140,6 +1120,8 @@ target=$target_alias
 if test "x$host_alias" != x; then
   if test "x$build_alias" = x; then
     cross_compiling=maybe
+    $as_echo "$as_me: WARNING: if you wanted to set the --build type, don't use --host.
+    If a cross compiler is detected then cross compile mode will be used" >&2
   elif test "x$build_alias" != "x$host_alias"; then
     cross_compiling=yes
   fi
@@ -1392,9 +1374,9 @@ test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
 RISC-V ISA Simulator configure ?
-generated by GNU Autoconf 2.69
+generated by GNU Autoconf 2.68
 
-Copyright (C) 2012 Free Software Foundation, Inc.
+Copyright (C) 2010 Free Software Foundation, Inc.
 This configure script is free software; the Free Software Foundation
 gives unlimited permission to copy, distribute and modify it.
 _ACEOF
@@ -1587,7 +1569,7 @@ $as_echo "$ac_try_echo"; } >&5
 	 test ! -s conftest.err
        } && test -s conftest$ac_exeext && {
 	 test "$cross_compiling" = yes ||
-	 test -x conftest$ac_exeext
+	 $as_test_x conftest$ac_exeext
        }; then :
   ac_retval=0
 else
@@ -1610,7 +1592,7 @@ This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
 It was created by RISC-V ISA Simulator $as_me ?, which was
-generated by GNU Autoconf 2.69.  Invocation command line was
+generated by GNU Autoconf 2.68.  Invocation command line was
 
   $ $0 $@
 
@@ -2085,7 +2067,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_CC="${ac_tool_prefix}gcc"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -2125,7 +2107,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_ac_ct_CC="gcc"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -2178,7 +2160,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_CC="${ac_tool_prefix}cc"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -2219,7 +2201,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     if test "$as_dir/$ac_word$ac_exec_ext" = "/usr/ucb/cc"; then
        ac_prog_rejected=yes
        continue
@@ -2277,7 +2259,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_CC="$ac_tool_prefix$ac_prog"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -2321,7 +2303,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_ac_ct_CC="$ac_prog"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -2767,7 +2749,8 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stdarg.h>
 #include <stdio.h>
-struct stat;
+#include <sys/types.h>
+#include <sys/stat.h>
 /* Most of the following tests are stolen from RCS 5.7's src/conf.sh.  */
 struct buf { int x; };
 FILE * (*rcsopen) (struct buf *, struct stat *, int);
@@ -2880,7 +2863,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_CXX="$ac_tool_prefix$ac_prog"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -2924,7 +2907,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_ac_ct_CXX="$ac_prog"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -3126,7 +3109,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_AR="${ac_tool_prefix}ar"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -3166,7 +3149,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_ac_ct_AR="ar"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -3218,7 +3201,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_RANLIB="${ac_tool_prefix}ranlib"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -3258,7 +3241,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_ac_ct_RANLIB="ranlib"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -3338,7 +3321,7 @@ case $as_dir/ in #((
     # by default.
     for ac_prog in ginstall scoinst install; do
       for ac_exec_ext in '' $ac_executable_extensions; do
-	if as_fn_executable_p "$as_dir/$ac_prog$ac_exec_ext"; then
+	if { test -f "$as_dir/$ac_prog$ac_exec_ext" && $as_test_x "$as_dir/$ac_prog$ac_exec_ext"; }; then
 	  if test $ac_prog = install &&
 	    grep dspmsg "$as_dir/$ac_prog$ac_exec_ext" >/dev/null 2>&1; then
 	    # AIX install.  It has an incompatible calling convention.
@@ -3439,7 +3422,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_stow="$ac_prog"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -3535,7 +3518,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_RUN="$ac_tool_prefix$ac_prog"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -3579,7 +3562,7 @@ do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
     ac_cv_prog_ac_ct_RUN="$ac_prog"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
@@ -3790,7 +3773,7 @@ do
     for ac_prog in grep ggrep; do
     for ac_exec_ext in '' $ac_executable_extensions; do
       ac_path_GREP="$as_dir/$ac_prog$ac_exec_ext"
-      as_fn_executable_p "$ac_path_GREP" || continue
+      { test -f "$ac_path_GREP" && $as_test_x "$ac_path_GREP"; } || continue
 # Check for GNU ac_path_GREP and select it if it is found.
   # Check for GNU $ac_path_GREP
 case `"$ac_path_GREP" --version 2>&1` in
@@ -3856,7 +3839,7 @@ do
     for ac_prog in egrep; do
     for ac_exec_ext in '' $ac_executable_extensions; do
       ac_path_EGREP="$as_dir/$ac_prog$ac_exec_ext"
-      as_fn_executable_p "$ac_path_EGREP" || continue
+      { test -f "$ac_path_EGREP" && $as_test_x "$ac_path_EGREP"; } || continue
 # Check for GNU ac_path_EGREP and select it if it is found.
   # Check for GNU $ac_path_EGREP
 case `"$ac_path_EGREP" --version 2>&1` in
@@ -4194,54 +4177,6 @@ else
 fi
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for dlopen in -ldl" >&5
-$as_echo_n "checking for dlopen in -ldl... " >&6; }
-if ${ac_cv_lib_dl_dlopen+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-ldl  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char dlopen ();
-int
-main ()
-{
-return dlopen ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_dl_dlopen=yes
-else
-  ac_cv_lib_dl_dlopen=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_dl_dlopen" >&5
-$as_echo "$ac_cv_lib_dl_dlopen" >&6; }
-if test "x$ac_cv_lib_dl_dlopen" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_LIBDL 1
-_ACEOF
-
-  LIBS="-ldl $LIBS"
-
-else
-  as_fn_error $? "libdl is required" "$LINENO" 5
-fi
-
-
 # Check whether --enable-fpu was given.
 if test "${enable_fpu+set}" = set; then :
   enableval=$enable_fpu;
@@ -4415,6 +4350,53 @@ $as_echo "$as_me: configuring default subproject : spike" >&6;}
 
 $as_echo "#define SPIKE_ENABLED /**/" >>confdefs.h
 
+      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for dlopen in -ldl" >&5
+$as_echo_n "checking for dlopen in -ldl... " >&6; }
+if ${ac_cv_lib_dl_dlopen+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-ldl  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char dlopen ();
+int
+main ()
+{
+return dlopen ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_dl_dlopen=yes
+else
+  ac_cv_lib_dl_dlopen=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_dl_dlopen" >&5
+$as_echo "$ac_cv_lib_dl_dlopen" >&6; }
+if test "x$ac_cv_lib_dl_dlopen" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBDL 1
+_ACEOF
+
+  LIBS="-ldl $LIBS"
+
+else
+  as_fn_error $? "libdl is required" "$LINENO" 5
+fi
+
 
 
 
@@ -4853,16 +4835,16 @@ if (echo >conf$$.file) 2>/dev/null; then
     # ... but there are two gotchas:
     # 1) On MSYS, both `ln -s file dir' and `ln file dir' fail.
     # 2) DJGPP < 2.04 has no symlinks; `ln -s' creates a wrapper executable.
-    # In both cases, we have to default to `cp -pR'.
+    # In both cases, we have to default to `cp -p'.
     ln -s conf$$.file conf$$.dir 2>/dev/null && test ! -f conf$$.exe ||
-      as_ln_s='cp -pR'
+      as_ln_s='cp -p'
   elif ln conf$$.file conf$$ 2>/dev/null; then
     as_ln_s=ln
   else
-    as_ln_s='cp -pR'
+    as_ln_s='cp -p'
   fi
 else
-  as_ln_s='cp -pR'
+  as_ln_s='cp -p'
 fi
 rm -f conf$$ conf$$.exe conf$$.dir/conf$$.file conf$$.file
 rmdir conf$$.dir 2>/dev/null
@@ -4922,16 +4904,28 @@ else
   as_mkdir_p=false
 fi
 
-
-# as_fn_executable_p FILE
-# -----------------------
-# Test if FILE is an executable regular file.
-as_fn_executable_p ()
-{
-  test -f "$1" && test -x "$1"
-} # as_fn_executable_p
-as_test_x='test -x'
-as_executable_p=as_fn_executable_p
+if test -x / >/dev/null 2>&1; then
+  as_test_x='test -x'
+else
+  if ls -dL / >/dev/null 2>&1; then
+    as_ls_L_option=L
+  else
+    as_ls_L_option=
+  fi
+  as_test_x='
+    eval sh -c '\''
+      if test -d "$1"; then
+	test -d "$1/.";
+      else
+	case $1 in #(
+	-*)set "./$1";;
+	esac;
+	case `ls -ld'$as_ls_L_option' "$1" 2>/dev/null` in #((
+	???[sx]*):;;*)false;;esac;fi
+    '\'' sh
+  '
+fi
+as_executable_p=$as_test_x
 
 # Sed expression to map a string onto a valid CPP name.
 as_tr_cpp="eval sed 'y%*$as_cr_letters%P$as_cr_LETTERS%;s%[^_$as_cr_alnum]%_%g'"
@@ -4953,7 +4947,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # values after options handling.
 ac_log="
 This file was extended by RISC-V ISA Simulator $as_me ?, which was
-generated by GNU Autoconf 2.69.  Invocation command line was
+generated by GNU Autoconf 2.68.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
   CONFIG_HEADERS  = $CONFIG_HEADERS
@@ -5015,10 +5009,10 @@ cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
 RISC-V ISA Simulator config.status ?
-configured by $0, generated by GNU Autoconf 2.69,
+configured by $0, generated by GNU Autoconf 2.68,
   with options \\"\$ac_cs_config\\"
 
-Copyright (C) 2012 Free Software Foundation, Inc.
+Copyright (C) 2010 Free Software Foundation, Inc.
 This config.status script is free software; the Free Software Foundation
 gives unlimited permission to copy, distribute and modify it."
 
@@ -5107,7 +5101,7 @@ fi
 _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 if \$ac_cs_recheck; then
-  set X $SHELL '$0' $ac_configure_args \$ac_configure_extra_args --no-create --no-recursion
+  set X '$SHELL' '$0' $ac_configure_args \$ac_configure_extra_args --no-create --no-recursion
   shift
   \$as_echo "running CONFIG_SHELL=$SHELL \$*" >&6
   CONFIG_SHELL='$SHELL'
diff --git a/riscv/riscv.ac b/riscv/riscv.ac
index b0b2282..a65039b 100644
--- a/riscv/riscv.ac
+++ b/riscv/riscv.ac
@@ -11,8 +11,6 @@ AC_CHECK_LIB(fesvr, libfesvr_is_present, [], [AC_MSG_ERROR([libfesvr is required
 
 AC_CHECK_LIB(pthread, pthread_create, [], [AC_MSG_ERROR([libpthread is required])])
 
-AC_CHECK_LIB(dl, dlopen, [], [AC_MSG_ERROR([libdl is required])])
-
 AC_ARG_ENABLE([fpu], AS_HELP_STRING([--disable-fpu], [Disable floating-point]))
 AS_IF([test "x$enable_fpu" != "xno"], [
   AC_DEFINE([RISCV_ENABLE_FPU],,[Define if floating-point instructions are supported])
diff --git a/spike/spike.ac b/spike/spike.ac
index e69de29..f8d63ce 100644
--- a/spike/spike.ac
+++ b/spike/spike.ac
@@ -0,0 +1 @@
+AC_CHECK_LIB(dl, dlopen, [], [AC_MSG_ERROR([libdl is required])])
diff --git a/spike/spike.cc b/spike/spike.cc
index da564b5..c8b4d7c 100644
--- a/spike/spike.cc
+++ b/spike/spike.cc
@@ -4,6 +4,7 @@
 #include "htif.h"
 #include "cachesim.h"
 #include "extension.h"
+#include <dlfcn.h>
 #include <fesvr/option_parser.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -24,6 +25,7 @@ static void help()
   fprintf(stderr, "  --dc=<S>:<W>:<B>     W ways, and B-byte blocks (with S and\n");
   fprintf(stderr, "  --l2=<S>:<W>:<B>     B both powers of 2).\n");
   fprintf(stderr, "  --extension=<name> Specify RoCC Extension\n");
+  fprintf(stderr, "  --extlib=<name>    Shared library to load\n");
   exit(1);
 }
 
@@ -51,6 +53,13 @@ int main(int argc, char** argv)
       fprintf(stderr, "unknown extension %s!\n", s), exit(-1);
     extension = extensions()[s];
   });
+  parser.option(0, "extlib", 1, [&](const char *s){
+    void *lib = dlopen(s, RTLD_NOW | RTLD_GLOBAL);
+    if (lib == NULL) {
+      fprintf(stderr, "Unable to load extlib '%s': %s\n", s, dlerror());
+      exit(-1);
+    }
+  });
 
   auto argv1 = parser.parse(argv);
   if (!*argv1)