ndk: Add crtbrand.c ; crtbegin_static.S includes "atexit.S" for x86/mips

"atexit" isn't defined in libc.a for x86/mips (unlike their arm's counterpart).
Include atexit.S otherwise app using atexit() may fail to link statically.

Also, add crtbegin.c to brand crtbegin_static/dynamic.c with .note.ABI-tag
section of given API level.  See $NDK/gen-platforms.sh

Change-Id: I2fdbb92119e3ca2da2c1ced6d77e63136ec35c34

ndk/platforms/android-9/arch-mips/src/crtbegin_static.S

@@ -228,4 +228,4 @@ $L3:
 	.weak	__register_frame_info
 
 .include "__dso_handle.S"
-/* NOTE: atexit() is  not be provided by crtbegin_static.S, but by libc.a */
+.include "atexit.S"

ndk/platforms/android-9/arch-x86/src/crtbegin_dynamic.S

@@ -60,10 +60,9 @@ _start:
         mov     $0, %edx
         pushl   %edx
         pushl   %eax
-        call     __libc_init
+        call    __libc_init
 
-0:
+0:  jmp   main
-        jmp   main
 
 1:  .long   __PREINIT_ARRAY__
     .long   __INIT_ARRAY__

ndk/platforms/android-9/arch-x86/src/crtbegin_static.S

@@ -134,6 +134,5 @@ frame_dummy:
 	.weak	__deregister_frame_info_bases
 
 #include "__dso_handle.S"
+#include "atexit.S"
 #include "__stack_chk_fail_local.S"
-/* NOTE: atexit() is  not be provided by crtbegin_static.S, but by libc.a */
-

ndk/platforms/common/src/crtbrand.c

@@ -0,0 +1,89 @@
+/*-
+ * Copyright 2000 David E. O'Brien, John D. Polstra.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* The following trick defines int32_t w/o including <stdint.h>
+   We want "int" to be 4-byte.  But just in case it isn't, the following
+   line turns into "typedef int int32_t[0]" and later fails with error messages
+   read like:
+
+      crtbrand.c:83: error: excess elements in struct initializer
+ */
+typedef int int32_t[sizeof(int) == 4];
+
+#define ABI_VENDOR	"GNU"
+#define ABI_SECTION	".note.ABI-tag"
+#define ABI_NOTETYPE	1
+#define ABI_OS		0
+#define ABI_OS_MAJOR	2
+#define ABI_OS_MINOR	6
+#define ABI_OS_TEENY	15
+#define ABI_ANDROID	1
+#define ABI_ANDROID_API	PLATFORM_SDK_VERSION
+
+/*
+ * Special ".note" entry specifying the ABI version.  See
+ * http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/noteabitag.html
+ * for more information.
+ *
+ * For all arches except sparc, gcc emits the section directive for the
+ * following struct with a PROGBITS type.  However, newer versions of binutils
+ * (after 2.16.90) require the section to be of NOTE type, to guarantee that the
+ * .note.ABI-tag section correctly ends up in the first page of the final
+ * executable.
+ *
+ * Unfortunately, there is no clean way to tell gcc to use another section type,
+ * so this C file (or the C file that includes it) must be compiled in multiple
+ * steps:
+ *
+ * - Compile the .c file to a .s file.
+ * - Edit the .s file to change the 'progbits' type to 'note', for the section
+ *   directive that defines the .note.ABI-tag section.
+ * - Compile the .s file to an object file.
+ *
+ * These steps are done in the invididual Makefiles for each applicable arch.
+ */
+static const struct {
+    int32_t	namesz;
+    int32_t	descsz;
+    int32_t	type;
+    char	name[sizeof ABI_VENDOR];
+    int32_t	os;
+    int32_t	major;
+    int32_t	minor;
+    int32_t	teeny;
+    int32_t	os_variant;
+    int32_t	android_api;
+} abitag __attribute__ ((section (ABI_SECTION), aligned(4), used)) = {
+    sizeof ABI_VENDOR,
+    6 * sizeof(int32_t),
+    ABI_NOTETYPE,
+    ABI_VENDOR,
+    ABI_OS,
+    ABI_OS_MAJOR,
+    ABI_OS_MINOR,
+    ABI_OS_TEENY,
+    ABI_ANDROID,
+    ABI_ANDROID_API,
+};