Test whether /dev/zero works before attemping to us it

diff --git a/sim/ppc/ChangeLog b/sim/ppc/ChangeLog
index e67bdfe995726a0ab83d3122349acc5c3ac20296..add31b5ff585fdbf586646da9046767712c0bf99 100644 (file)
--- a/sim/ppc/ChangeLog
+++ b/sim/ppc/ChangeLog
@@ -1,3 +1,17 @@
+Mon Aug 12 18:42:37 1996  Michael Meissner  <meissner@tiktok.cygnus.com>
+
+       * configure.in: Test whether /dev/zero works on the system, and if
+       it does, define HAVE_DEVZERO.
+       * configure: Regenerate.
+
+       * emul_generic.c (emul_add_tree_hardware): Do not add /iobus/disk
+       if we don't have a working /dev/zero on the system.
+
+       * emul_bugapi.c (emul_bugapi_init): If HAVE_DEVZERO is not
+       defined, don't add disk support.
+       (emul_bugapi_do_diskio): Ditto.
+       (emul_bugapi_instruction_call): Ditto.
+
 Wed Aug  7 14:34:20 1996  Michael Meissner  <meissner@tiktok.cygnus.com>
 
        * emul_unix.c (HAVE_TCGETATTR): If HAVE_TERMIOS_STRUCTURE is not

diff --git a/sim/ppc/Makefile.in b/sim/ppc/Makefile.in
index 5ab3c22149972724d33ee489affb51b9efeed64f..1d36f655f77f41fec1ec803e2027a01b73da991e 100644 (file)
--- a/sim/ppc/Makefile.in
+++ b/sim/ppc/Makefile.in
@@ -88,6 +88,7 @@ MODEL_CFLAGS = @sim_model@ @sim_default_model@ @sim_model_issue@
 STDIO_CFLAGS = @sim_stdio@
 TERMIO_CFLAGS = @sim_termio@
 WARNING_CFLAGS = @sim_warnings@
+DEVZERO_CFLAGS = @sim_devzero@
 CONFIG_CFLAGS = $(BSWAP_CFLAGS) \
   $(ENDIAN_CFLAGS) \
   $(REGPARM_CFLAGS) \
@@ -107,7 +108,8 @@ CONFIG_CFLAGS = $(BSWAP_CFLAGS) \
   $(MONITOR_CFLAGS) \
   $(MODEL_CFLAGS) \
   $(STDIO_CFLAGS) \
-  $(TERMIO_CFLAGS)
+  $(TERMIO_CFLAGS) \
+  $(DEVZERO_CFLAGS)
 
 STD_CFLAGS     = $(CFLAGS) $(INLINE_CFLAGS) $(CONFIG_CFLAGS) $(WARNING_CFLAGS) $(SIM_CFLAGS) $(HDEFINES) $(TDEFINES) $(INCLUDES)
 NOWARN_CFLAGS  = $(CFLAGS) $(INLINE_CFLAGS) $(CONFIG_CFLAGS) $(SIM_CFLAGS) $(HDEFINES) $(TDEFINES) $(INCLUDES)

diff --git a/sim/ppc/configure.in b/sim/ppc/configure.in
index 1314a9340d0e803a6c7dd645d2dd2ac6e55fd67f..4924f78b7f086791cc545fe3c4a553f4ff723acc 100644 (file)
--- a/sim/ppc/configure.in
+++ b/sim/ppc/configure.in
@@ -593,6 +593,33 @@ else
   ac_cv_termio_cline=no
 fi
 
+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
+
 AC_SUBST(CC_FOR_BUILD)
 AC_SUBST(CFLAGS)
 AC_SUBST(HDEFINES)
@@ -637,6 +664,7 @@ AC_SUBST(sim_default_model)
 AC_SUBST(sim_model_issue)
 AC_SUBST(sim_stdio)
 AC_SUBST(sim_termio)
+AC_SUBST(sim_devzero)
 
 AC_OUTPUT(Makefile,
 [case x$CONFIG_HEADERS in xconfig.h:config.in) echo > stamp-h ;; esac])