# build it if these headers aren't available.
AC_CHECK_HEADERS([sys/mman.h sys/ioctl.h], [], [HW_BEAGLELOGIC="no"])
+# The BayLibre ACME driver needs sys/timerfd.h. Don't try to build it if
+# this header isn't available.
+AC_CHECK_HEADERS([sys/timerfd.h], [], [HW_BAYLIBRE_ACME="no"])
+
# The ACME driver can only be built for Linux.
case "$host" in
*linux*) ;;