altos: Add floating point math functions from newlib

[fw/altos] / configure.ac

diff --git a/configure.ac b/configure.ac
index 8024b7c602d674a538ef89026d20c76917676213..05d4913bc00b9da604036713bc6aa9a4f0323ffe 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -330,8 +330,30 @@ if test "x$HAVE_AVR_CC" = "xno" -o "x$HAVE_AVR_OBJCOPY" = "xno"; then
        AC_MSG_WARN([AVR compiler and objcopy not found, atmel binaries will not be built])
        HAVE_AVR_CC=no
 else
-       AVR_CC=$with_avr_cc
-       AVR_OBJCOPY=$with_avr_objcopy
+       save_CC="$CC"
+       save_CFLAGS="$CFLAGS"
+       save_LIBS="$LIBS"
+
+       CC="$with_avr_cc"
+       CFLAGS="-mmcu=attiny85"
+       AC_LANG_PUSH([C])
+       AC_MSG_CHECKING([if ]$with_avr_cc[ can link programs])
+       AC_LINK_IFELSE([AC_LANG_PROGRAM([])],
+                         [AVR_LINK=yes],
+                         [AVR_LINK=no])
+        AC_MSG_RESULT([$AVR_LINK])
+       AC_LANG_POP([C])
+
+       LIBS="$save_LIBS"
+       CFLAGS="$save_CFLAGS"
+       CC="$save_CC"
+
+       if test "x$AVR_LINK" = xyes; then
+               AVR_CC=$with_avr_cc
+               AVR_OBJCOPY=$with_avr_objcopy
+       else
+               HAVE_AVR_CC=no;
+       fi
 fi
 
 AC_SUBST(AVR_CC)