+dnl Figure out if /dev/zero exists or not
+sim_devzero=""
+AC_MSG_CHECKING(for /dev/zero)
+AC_CACHE_VAL(ac_cv_devzero,
+[AC_TRY_RUN([#include <fcntl.h>
+main () {
+ char buf[2048];
+ int i;
+ int fd = open ("/dev/zero", O_RDONLY);
+ if (fd < 0)
+ return 1;
+ for (i = 0; i < sizeof (buf); i++)
+ buf[i] = 1;
+ if (read (fd, buf, sizeof (buf)) != sizeof (buf))
+ return 1;
+ for (i = 0; i < sizeof (buf); i++)
+ if (buf[i])
+ return 1;
+ return 0;
+}],[ac_cv_devzero=yes],[ac_cv_devzero=no],[ac_cv_devzero=no])])
+AC_MSG_RESULT($ac_cv_devzero)
+if test $ac_cv_devzero = yes; then
+ sim_devzero="-DHAVE_DEVZERO"
+else
+ sim_devzero=""
+fi
+