1 files changed, 48 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/arm/libc-do-syscall.S b/ports/sysdeps/unix/sysv/linux/arm/libc-do-syscall.S
new file mode 100644
index 0000000000..0ec81734f8
--- /dev/null
+++ b/ports/sysdeps/unix/sysv/linux/arm/libc-do-syscall.S
@@ -0,0 +1,48 @@
+/* Copyright (C) 2010-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+
+/* Out-of-line syscall stub.  We expect the system call number in ip
+   and return the raw result in r0.  No registers are clobbered.
+   We could avoid using the stack for this, but the goal is accurate
+   unwind information - and while there is a reserved prefix in the
+   ARM unwind tables for register to register moves, the actual opcodes
+   are not defined.  */
+
+#if defined(__thumb__)
+	.thumb
+	.syntax unified
+	.hidden __libc_do_syscall
+
+#undef CALL_MCOUNT
+#define CALL_MCOUNT
+
+ENTRY (__libc_do_syscall)
+	.fnstart
+	push	{r7, lr}
+	.save	{r7, lr}
+	cfi_adjust_cfa_offset (8)
+	cfi_rel_offset (r7, 0)
+	cfi_rel_offset (lr, 4)
+	mov	r7, ip
+	swi	0x0
+	pop	{r7, pc}
+	.fnend
+END (__libc_do_syscall)
+
+#endif /* __thumb__ */