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[PATCH 14/21] ARC: Enable __start as entry point vs. canonical _start
- From: Vineet Gupta <vineet dot gupta1 at synopsys dot com>
- To: <libc-alpha at sourceware dot org>
- Cc: <linux-snps-arc at lists dot infradead dot org>, Vineet Gupta <vineet dot gupta1 at synopsys dot com>
- Date: Tue, 18 Dec 2018 13:04:36 -0800
- Subject: [PATCH 14/21] ARC: Enable __start as entry point vs. canonical _start
- References: <1545167083-16764-1-git-send-email-vgupta@synopsys.com>
ARC linker scripts have defined __start as entry point so to not break
ABI for uClibc et al we allow __start for glibc as well
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
ChangeLog | 3 +++
sysdeps/arc/dl-machine.h | 14 ++++++++++----
sysdeps/arc/entry.h | 5 +++++
sysdeps/arc/start.S | 14 +++++++++++---
4 files changed, 29 insertions(+), 7 deletions(-)
create mode 100644 sysdeps/arc/entry.h
diff --git a/ChangeLog b/ChangeLog
index 6628960c487e..86e4db890850 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -105,6 +105,9 @@
* sysdeps/unix/sysv/linux/arc/configure: New file.
* sysdeps/unix/sysv/linux/arc/configure.ac: New file.
* sysdeps/unix/sysv/linux/arc/shlib-versions: New file.
+ * sysdeps/arc/dl-machine.h: replace _start with __start.
+ * sysdeps/arc/start.S: likewise.
+ * sysdeps/arc/entry.h: Add ENTRY_POINT define check.
2018-12-17 Joseph Myers <joseph@codesourcery.com>
diff --git a/sysdeps/arc/dl-machine.h b/sysdeps/arc/dl-machine.h
index da1aef79152d..02727a3a4d47 100644
--- a/sysdeps/arc/dl-machine.h
+++ b/sysdeps/arc/dl-machine.h
@@ -21,6 +21,12 @@
#define ELF_MACHINE_NAME "arc"
+#include <entry.h>
+
+#ifndef ENTRY_POINT
+#error ENTRY_POINT needs to be defined for ARC
+#endif
+
#include <string.h>
#include <link.h>
#include <dl-tls.h>
@@ -150,9 +156,9 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
#define RTLD_START asm ("\
.text \n\
-.globl _start \n\
-.type _start, @function \n\
-_start: \n\
+.globl __start \n\
+.type __start, @function \n\
+__start: \n\
; (1). bootstrap ld.so \n\
bl.d _dl_start \n\
mov_s r0, sp ; pass ptr to aux vector tbl \n\
@@ -182,7 +188,7 @@ _start: \n\
add r0, pcl, _dl_fini@pcl \n\
j [r13] \n\
\n\
- .size _start,.-_start \n\
+ .size __start,.-__start \n\
.previous \n\
");
diff --git a/sysdeps/arc/entry.h b/sysdeps/arc/entry.h
new file mode 100644
index 000000000000..adb01d981afd
--- /dev/null
+++ b/sysdeps/arc/entry.h
@@ -0,0 +1,5 @@
+#ifndef __ASSEMBLY__
+extern void __start (void) attribute_hidden;
+#endif
+
+#define ENTRY_POINT __start
diff --git a/sysdeps/arc/start.S b/sysdeps/arc/start.S
index 119d596db07f..79e73e27d00d 100644
--- a/sysdeps/arc/start.S
+++ b/sysdeps/arc/start.S
@@ -34,7 +34,14 @@
<http://www.gnu.org/licenses/>. */
+#define __ASSEMBLY__ 1
+#include <entry.h>
+#ifndef ENTRY_POINT
+#error ENTRY_POINT needs to be defined for ARC
+#endif
+
/* When we enter this piece of code, the program stack looks like this:
+
argc argument counter (integer)
argv[0] program name (pointer)
argv[1...N] program args (pointers)
@@ -45,9 +52,9 @@
*/
.text
.align 4
- .global _start
- .type _start,@function
-_start:
+ .global __start
+ .type __start,@function
+__start:
mov fp, 0
ld_s r1, [sp] ; argc
@@ -71,6 +78,7 @@ _start:
/* Should never get here.... */
flag 1
+ .size __start,.-__start
/* Define a symbol for the first piece of initialized data. */
.data
--
2.7.4