Relocate AArch64 from ports to libc.

This patch moves the AArch64 port to the main sysdeps hierarchy.  The
move is essentially:

  git mv ports/sysdeps/aarch64 sysdeps/aarch64
  git mv ports/sysdeps/unix/sysv/linux/aarch64 sysdeps/unix/sysv/linux/aarch64

The README is updated and I've updated ChangeLog.aarch64 along the
lines of the ARM move.  The AArch64 build has been tested to confirm
that there were no changes in objdump -dr output or the shared
objects.

1 files changed, 74 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/aarch64/makecontext.c b/sysdeps/unix/sysv/linux/aarch64/makecontext.c
new file mode 100644
index 0000000000..806eab2cf9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/makecontext.c
@@ -0,0 +1,74 @@
+/* Create new context.
+   Copyright (C) 2002-2014 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>
+#include <stdarg.h>
+#include <stdint.h>
+#include <ucontext.h>
+
+
+/* makecontext sets up a stack and the registers for the
+   user context.  The stack looks like this:
+
+               +-----------------------+
+	       | padding as required   |
+               +-----------------------+
+    sp ->      | parameter 7-n         |
+               +-----------------------+
+
+   The registers are set up like this:
+     %x0 .. %x7: parameter 1 to 8
+     %x19   : uc_link
+     %sp    : stack pointer.
+*/
+
+void
+__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
+{
+  extern void __startcontext (void);
+  unsigned long int *sp;
+  va_list ap;
+  int i;
+
+  sp = (unsigned long int *)
+    ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+
+  /* Allocate stack arguments.  */
+  sp -= argc < 8 ? 0 : argc - 8;
+
+  /* Keep the stack aligned.  */
+  sp = (unsigned long int *) (((uintptr_t) sp) & -16L);
+
+  ucp->uc_mcontext.regs[19] = (uintptr_t) ucp->uc_link;
+  ucp->uc_mcontext.sp = (uintptr_t) sp;
+  ucp->uc_mcontext.pc = (uintptr_t) func;
+  ucp->uc_mcontext.regs[29] = (uintptr_t) 0;
+  ucp->uc_mcontext.regs[30] = (uintptr_t) &__startcontext;
+
+  va_start (ap, argc);
+  for (i = 0; i < argc; ++i)
+    if (i < 8)
+      ucp->uc_mcontext.regs[i] = va_arg (ap, unsigned long int);
+    else
+      sp[i - 8] = va_arg (ap, unsigned long int);
+
+  va_end (ap);
+}
+
+weak_alias (__makecontext, makecontext)