add experimental aarch64 support

Ported over from GNU C Library and runtime tested in Qemu.

1 files changed, 37 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/aarch64/vfork.S b/libc/sysdeps/linux/aarch64/vfork.S
new file mode 100644
index 000000000..9a8fd469a
--- /dev/null
+++ b/libc/sysdeps/linux/aarch64/vfork.S
@@ -0,0 +1,37 @@
+/* Copyright (C) 1999-2017 Free Software Foundation, Inc.
+
+   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>
+#define _ERRNO_H	1
+#include <bits/errno.h>
+
+/* Clone the calling process, but without copying the whole address space.
+   The calling process is suspended until the new process exits or is
+   replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
+   and the process ID of the new process to the old process.  */
+
+ENTRY (vfork)
+
+	mov	x0, #0x4111	/* CLONE_VM | CLONE_VFORK | SIGCHLD */
+	mov	x1, sp
+	DO_CALL (clone, 2)
+
+	cmn	x0, #4095
+	b.cs    .Lsyscall_error
+	RET
+
+PSEUDO_END (vfork)
+libc_hidden_def (vfork)