Make .note.android.ident section type SH_NOTE

The .note.android.ident section is only used by GDB, which doesn't
care what section type the section is, but it would be convenient
for readelf -n to be able to find the section too.

The old way of getting the .note.android.ident section to be of type
SH_NOTE involved compiling from .c to .s using gcc, running sed to
change progbits to note, and then compiling from .s to .o using gcc.
Since crtbrand.c only contains a section containing data, a
crtbrand.S can be checked in that will compile on all platforms,
avoiding the need for sed.

Also add crtbrand.o to crtbegin_so.o so that libraries also get
the note, and to the crt workaround in arm libc.so.

Change-Id: Ica71942a6af4553b56978ceaa288b3f4c15ebfa2
diff --git a/libc/Android.mk b/libc/Android.mk
index 75bb616..fdaa8ee 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -1179,8 +1179,10 @@
 # special for arm
 LOCAL_NO_CRT_arm := true
 LOCAL_CFLAGS_arm += -DCRT_LEGACY_WORKAROUND
+LOCAL_ASFLAGS_arm += $(libc_crt_target_cflags)
 LOCAL_SRC_FILES_arm += \
     arch-common/bionic/crtbegin_so.c \
+    arch-common/bionic/crtbrand.S \
     arch-arm/bionic/atexit_legacy.c \
     arch-common/bionic/crtend_so.S
 LOCAL_ADDRESS_SANITIZER := false
diff --git a/libc/arch-common/bionic/crtbrand.S b/libc/arch-common/bionic/crtbrand.S
new file mode 100644
index 0000000..11bbfbe
--- /dev/null
+++ b/libc/arch-common/bionic/crtbrand.S
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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
+ * COPYRIGHT OWNER OR CONTRIBUTORS 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.
+ */
+
+	.section	.note.android.ident,"a",%note
+	.align	2
+	.type	abitag, %object
+abitag:
+	.long	2f-1f			/* int32_t namesz */
+	.long	3f-2f			/* int32_t descsz */
+	.long	1			/* int32_t type */
+1:	.ascii	"Android\0"		/* char name[] */
+2:	.long	PLATFORM_SDK_VERSION	/* int32_t android_api */
+3:
+	.size	abitag, .-abitag
diff --git a/libc/bionic/crtbrand.c b/libc/bionic/crtbrand.c
deleted file mode 100644
index a726c51..0000000
--- a/libc/bionic/crtbrand.c
+++ /dev/null
@@ -1,48 +0,0 @@
-/*-
- * 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.
- */
-
-#include <stdint.h>
-
-#define ABI_VENDOR	"Android"
-#define ABI_SECTION	".note.android.ident"
-#define ABI_NOTETYPE	1
-#define ABI_ANDROID_API	PLATFORM_SDK_VERSION
-
-/*
- * Special ".note" entry to tag an Android binary and specify the ABI version.
- */
-static const struct {
-    int32_t	namesz;
-    int32_t	descsz;
-    int32_t	type;
-    char	name[sizeof ABI_VENDOR];
-    int32_t	android_api;
-} abitag __attribute__ ((section (ABI_SECTION), aligned(4), used)) = {
-    sizeof ABI_VENDOR,
-    sizeof(int32_t),
-    ABI_NOTETYPE,
-    ABI_VENDOR,
-    ABI_ANDROID_API,
-};
diff --git a/libc/crt.mk b/libc/crt.mk
index 410f229..6365332 100644
--- a/libc/crt.mk
+++ b/libc/crt.mk
@@ -31,18 +31,19 @@
 
 my_libc_crt_target_ldflags := $(libc_crt_target_ldflags_$(my_arch))
 
-
+# crtbrand.S -> crtbrand.o
 GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbrand.o
 $(GEN): PRIVATE_CC := $($(my_2nd_arch_prefix)TARGET_CC)
 $(GEN): PRIVATE_CFLAGS := $(my_libc_crt_target_so_cflags)
-$(GEN): $(LOCAL_PATH)/bionic/crtbrand.c
+$(GEN): $(LOCAL_PATH)/arch-common/bionic/crtbrand.S
+	@mkdir -p $(dir $@)
 	$(hide) $(PRIVATE_CC) $(PRIVATE_CFLAGS) \
 		-MD -MF $(@:%.o=%.d) -o $@ -c $<
 	$(transform-d-to-p)
 -include $(GEN:%.o=%.P)
 
-
-GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_so.o
+# crtbegin_so.c -> crtbegin_so1.o
+GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_so1.o
 $(GEN): PRIVATE_CC := $($(my_2nd_arch_prefix)TARGET_CC)
 $(GEN): PRIVATE_CFLAGS := $(my_libc_crt_target_so_cflags)
 $(GEN): $(my_libc_crt_target_crtbegin_so_file)
@@ -52,7 +53,16 @@
 	$(transform-d-to-p)
 -include $(GEN:%.o=%.P)
 
+# crtbegin_so1.o + crtbrand.o -> crtbegin_so.o
+GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_so.o
+$(GEN): PRIVATE_LD := $($(my_2nd_arch_prefix)TARGET_LD)
+$(GEN): PRIVATE_LDFLAGS := $(my_libc_crt_target_ldflags)
+$(GEN): $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_so1.o \
+    $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbrand.o
+	@mkdir -p $(dir $@)
+	$(hide) $(PRIVATE_LD) $(PRIVATE_LDFLAGS) -r -o $@ $^
 
+# crtend_so.S -> crtend_so.o
 GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtend_so.o
 $(GEN): PRIVATE_CC := $($(my_2nd_arch_prefix)TARGET_CC)
 $(GEN): PRIVATE_CFLAGS := $(my_libc_crt_target_so_cflags)
@@ -63,8 +73,7 @@
 	$(transform-d-to-p)
 -include $(GEN:%.o=%.P)
 
-
-# The following two are installed to device
+# crtbegin_so.o and crtend_so.o are installed to device
 GEN := $($(my_2nd_arch_prefix)TARGET_OUT_SHARED_LIBRARIES)/crtbegin_so.o
 $(GEN): $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_so.o
 	$(hide) mkdir -p $(dir $@) && cp -f $< $@
@@ -75,7 +84,7 @@
 	$(hide) mkdir -p $(dir $@) && cp -f $< $@
 ALL_GENERATED_SOURCES += $(GEN)
 
-
+# crtbegin.c -> crtbegin_static1.o
 GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_static1.o
 $(GEN): PRIVATE_CC := $($(my_2nd_arch_prefix)TARGET_CC)
 $(GEN): PRIVATE_CFLAGS := $(my_libc_crt_target_cflags)
@@ -86,7 +95,7 @@
 	$(transform-d-to-p)
 -include $(GEN:%.o=%.P)
 
-
+# crtbegin_static1.o + crtbrand.o -> crtbegin_static.o
 GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_static.o
 $(GEN): PRIVATE_LD := $($(my_2nd_arch_prefix)TARGET_LD)
 $(GEN): PRIVATE_LDFLAGS := $(my_libc_crt_target_ldflags)
@@ -95,7 +104,7 @@
 	@mkdir -p $(dir $@)
 	$(hide) $(PRIVATE_LD) $(PRIVATE_LDFLAGS) -r -o $@ $^
 
-
+# crtbegin.c -> crtbegin_dynamic1.o
 GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_dynamic1.o
 $(GEN): PRIVATE_CC := $($(my_2nd_arch_prefix)TARGET_CC)
 $(GEN): PRIVATE_CFLAGS := $(my_libc_crt_target_cflags)
@@ -106,7 +115,7 @@
 	$(transform-d-to-p)
 -include $(GEN:%.o=%.P)
 
-
+# crtbegin_dynamic1.o + crtbrand.o -> crtbegin_dynamic.o
 GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtbegin_dynamic.o
 $(GEN): PRIVATE_LD := $($(my_2nd_arch_prefix)TARGET_LD)
 $(GEN): PRIVATE_LDFLAGS := $(my_libc_crt_target_ldflags)
@@ -115,7 +124,7 @@
 	@mkdir -p $(dir $@)
 	$(hide) $(PRIVATE_LD) $(PRIVATE_LDFLAGS) -r -o $@ $^
 
-
+# crtend.S -> crtend_android.o
 # We rename crtend.o to crtend_android.o to avoid a
 # name clash between gcc and bionic.
 GEN := $($(my_2nd_arch_prefix)TARGET_OUT_INTERMEDIATE_LIBRARIES)/crtend_android.o