nds32: add NPTL/TLS, *context function, libm changes and code cleanup

This commit includes following features.
1. Support NPTL/TLS
2. Add libm function which is used to handle FP rounding and excpetions
   (ex: fclrexcpt,fedisblxcpti,feenablxcpt... )
3. Add *context function for operating user context
   (ex: setcontext,getcontext,makecontext... )
4. Change the return flow from signal handler
5. Cleanup of old code

The testsuite only has 2 errors, tst-cpuclock1 and tst-cputimer1,
which are related to timing accuracy. (math and locale tests are disabled)

Signed-off-by: Vincent Ren-Wei Chen <vincentc@andestech.com>

1 files changed, 77 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/nds32/makecontext.c b/libc/sysdeps/linux/nds32/makecontext.c
new file mode 100644
index 000000000..d8f38aa15
--- /dev/null
+++ b/libc/sysdeps/linux/nds32/makecontext.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Copyright (C) 2011-2013 Free Software Foundation, Inc.
+   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
+
+   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 <stdarg.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.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:
+     $r0 .. $r5: parameter 1 to 6
+     $r6   : uc_link
+     $sp   : stack pointer.
+*/
+void
+__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
+{
+  extern void __startcontext (void);
+  unsigned long int *sp;
+  unsigned long *regptr;
+  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 < 6 ? 0 : argc - 6;
+
+  /* Keep the stack aligned.  */
+  sp = (unsigned long int *) (((uintptr_t) sp) & -8L);
+
+  ucp->uc_mcontext.nds32_r6 = (uintptr_t) ucp->uc_link;
+  ucp->uc_mcontext.nds32_sp = (uintptr_t) sp;
+  ucp->uc_mcontext.nds32_ipc = (uintptr_t) func;
+  ucp->uc_mcontext.nds32_lp = (uintptr_t) &__startcontext;
+
+  va_start (ap, argc);
+  regptr = &ucp->uc_mcontext.nds32_r0;
+  for (i = 0; i < argc; ++i)
+    if (i < 6)
+      *regptr++ = va_arg (ap, unsigned long int);
+    else
+      sp[i - 6] = va_arg (ap, unsigned long int);
+
+  va_end (ap);
+
+}
+weak_alias (__makecontext, makecontext)