This is step 1 in an effort to unify the start-up files for the

various architectures.  Now all the work is done in crtbegin.c.
It doesn't contain any assembly language code, so it should work
fine on all architectures.  (I have tested it on the i386 and the
alpha.) The old assembly language files crt[in].S are now empty
shells that generate no code or data.  They should not be removed
any time soon, because the various versions of gcc in src and ports
expect them to exist.

Next I will move crtbegin.c into a new common machine-independent
directory, and adjust the i386-elf Makefile to use that version.
After that I will adjust the alpha Makefile to use the common
version too.

Requested by:	obrien

1 files changed, 50 insertions, 7 deletions

diff --git a/lib/csu/common/crtbegin.c b/lib/csu/common/crtbegin.c
index 7c1f11e..7693d2b 100644
--- a/lib/csu/common/crtbegin.c
+++ b/lib/csu/common/crtbegin.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright 1996-1998 John D. Polstra.
+ * Copyright 1996, 1997, 1998, 2000 John D. Polstra.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -25,16 +25,17 @@
  * $FreeBSD$
  */
 
-#include <sys/cdefs.h>
+#include <sys/param.h>
+
+#define ABI_VENDOR	"FreeBSD"
+#define ABI_SECTION	".note.ABI-tag"
+#define ABI_NOTETYPE	1
 
 typedef void (*fptr)(void);
 
 static fptr ctor_list[1] __attribute__((section(".ctors"))) = { (fptr) -1 };
 static fptr dtor_list[1] __attribute__((section(".dtors"))) = { (fptr) -1 };
 
-static void do_ctors(void) __unused;
-static void do_dtors(void) __unused;
-
 static void
 do_ctors(void)
 {
@@ -55,5 +56,47 @@ do_dtors(void)
 	(**fpp)();
 }
 
-__asm__(".section .init,\"ax\",@progbits; call do_ctors; .previous");
-__asm__(".section .fini,\"ax\",@progbits; call do_dtors; .previous");
+/*
+ * With very large programs on some architectures (e.g., the Alpha),
+ * it is possible to get relocation overflows on the limited
+ * displacements of call/bsr instructions.  It is particularly likely
+ * for the calls from _init() and _fini(), because they are in
+ * separate sections.  Avoid the problem by forcing indirect calls.
+ */
+static void (*p_do_ctors)(void) = do_ctors;
+static void (*p_do_dtors)(void) = do_dtors;
+
+extern void _init(void) __attribute__((section(".init")));
+
+void
+_init(void)
+{
+	(*p_do_ctors)();
+}
+
+extern void _fini(void) __attribute__((section(".fini")));
+
+void
+_fini(void)
+{
+	(*p_do_dtors)();
+}
+
+/*
+ * Special ".note" entry specifying the ABI version.  See
+ * http://www.netbsd.org/Documentation/kernel/elf-notes.html
+ * for more information.
+ */
+static const struct {
+    int32_t	namesz;
+    int32_t	descsz;
+    int32_t	type;
+    char	name[sizeof ABI_VENDOR];
+    int32_t	desc;
+} abitag __attribute__ ((section (ABI_SECTION))) = {
+    sizeof ABI_VENDOR,
+    sizeof(int32_t),
+    ABI_NOTETYPE,
+    ABI_VENDOR,
+    __FreeBSD_version
+};