add nomath option for builds without a math library

configure.ac

@@ -536,6 +536,25 @@ fi
 
 
 # MATH LIBRARY SELECTION
+
+# no math library
+AC_ARG_ENABLE([nomath],
+    [AS_HELP_STRING([--enable-nomath],[Enable no math library (default: disabled)])],
+    [ ENABLED_NOMATH=$enableval ],
+    [ ENABLED_NOMATH="no" ]
+    )
+
+if test "$ENABLED_NOMATH" = "yes"
+then
+    DEF_SP_MATH="no"
+    DEF_FAST_MATH="no"
+    ENABLED_SP_MATH_DEFAULT=no
+    AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_NO_MATH"
+    ENABLED_HEAPMATH="no"
+    ENABLED_SP="no"
+    ENABLED_SP_MATH_ALL="no"
+fi
+
 # Single Precision maths implementation
 AC_ARG_ENABLE([sp],
     [AS_HELP_STRING([--enable-sp],[Enable Single Precision maths implementation (default: disabled)])],
@@ -671,7 +690,7 @@ AC_ARG_ENABLE([heapmath],
     [ ENABLED_HEAPMATH=$enableval ],
     [ ENABLED_HEAPMATH=no]
     )
-if test "x$ENABLED_HEAPMATH" = "xyes" || (test "x$ENABLED_SP_MATH_ALL" = "xno" && test "x$ENABLED_FASTMATH" = "xno" && test "x$ENABLED_SP_MATH" = "xno")
+if test "x$ENABLED_HEAPMATH" = "xyes" || (test "x$ENABLED_NOMATH" = "xno" && test "x$ENABLED_SP_MATH_ALL" = "xno" && test "x$ENABLED_FASTMATH" = "xno" && test "x$ENABLED_SP_MATH" = "xno")
 then
     AM_CFLAGS="$AM_CFLAGS -DUSE_INTEGER_HEAP_MATH"
     ENABLED_HEAPMATH="yes"

wolfssl/wolfcrypt/settings.h

@@ -2036,6 +2036,11 @@ extern void uITRON4_free(void *p) ;
          *      Constant time: Not supported
          *      Enable:        USE_INTEGER_HEAP_MATH
          */
+    #elif defined(WOLFSSL_NO_MATH)
+        /*  5) No math library compiled in
+         *      Does not support any public key operations or algorithms that
+         *      require the math library.
+         */
     #else
         /* default is SP Math. */
         #define WOLFSSL_SP_MATH_ALL