1 files changed, 79 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/nios2/makecontext.c b/sysdeps/unix/sysv/linux/nios2/makecontext.c
new file mode 100644
index 0000000000..5df951a4e6
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/nios2/makecontext.c
@@ -0,0 +1,79 @@
+/* Create new context.
+   Copyright (C) 2015 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 ->      | parameters 5 to n     |
+               +-----------------------+
+
+   The registers are set up like this:
+     r4--r7 : parameter 1 to 4
+     r16    : uc_link
+     sp     : stack pointer.
+*/
+
+void
+__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
+{
+  extern void __startcontext (void);
+  unsigned long *sp;
+  va_list ap;
+  int i;
+
+  sp = (unsigned long *)
+    ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+
+  /* Allocate stack arguments.  */
+  sp -= argc < 4 ? 0 : argc - 4;
+
+  /* Keep the stack aligned.  */
+  sp = (unsigned long*) (((uintptr_t) sp) & -4L);
+
+  /* Init version field.  */
+  ucp->uc_mcontext.version = 2;
+  /* Keep uc_link in r16.  */
+  ucp->uc_mcontext.regs[15] = (uintptr_t) ucp->uc_link;
+  /* Return address points to __startcontext().  */
+  ucp->uc_mcontext.regs[23] = (uintptr_t) &__startcontext;
+  /* Frame pointer is null.  */
+  ucp->uc_mcontext.regs[24] = (uintptr_t) 0;
+  /* Restart in user-space starting at 'func'.  */
+  ucp->uc_mcontext.regs[27] = (uintptr_t) func;
+  /* Set stack pointer.  */
+  ucp->uc_mcontext.regs[28] = (uintptr_t) sp;
+
+  va_start (ap, argc);
+  for (i = 0; i < argc; ++i)
+    if (i < 4)
+      ucp->uc_mcontext.regs[i + 3] = va_arg (ap, unsigned long);
+    else
+      sp[i - 4] = va_arg (ap, unsigned long);
+
+  va_end (ap);
+}
+
+weak_alias (__makecontext, makecontext)