RISC-V: ABI Implementation

This patch contains code that needs to directly know about the RISC-V
ABI, which is specified in a work-in-progress psABI document:

  https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md

This is meant to contain all the RISC-V code that needs to explicitly
name registers or manage in-memory structure layout.  This does not
contain any of the Linux-specific code.

2018-01-29  Palmer Dabbelt  <palmer@sifive.com>

        * sysdeps/riscv/__longjmp.S: New file.
        * sysdeps/riscv/backtrace.c: Likewise.
        * sysdeps/riscv/bits/endian.h: Likewise.
        * sysdeps/riscv/bits/setjmp.h: Likewise.
        * sysdeps/riscv/bits/wordsize.h: Likewise.
        * sysdeps/riscv/bsd-_setjmp.c: Likewise.
        * sysdeps/riscv/bsd-setjmp.c: Likewise.
        * sysdeps/riscv/dl-trampoline.S: Likewise.
        * sysdeps/riscv/gccframe.h: Likewise.
        * sysdeps/riscv/jmpbuf-offsets.h: Likewise.
        * sysdeps/riscv/jmpbuf-unwind.h: Likewise.
        * sysdeps/riscv/machine-gmon.h: Likewise.
        * sysdeps/riscv/memusage.h: Likewise.
        * sysdeps/riscv/setjmp.S: Likewise.
        * sysdeps/riscv/sys/asm.h: Likewise.
        * sysdeps/riscv/tls-macros.h: Likewise.

1 files changed, 37 insertions, 0 deletions

diff --git a/sysdeps/riscv/machine-gmon.h b/sysdeps/riscv/machine-gmon.h
new file mode 100644
index 0000000000..a50d50a2e1
--- /dev/null
+++ b/sysdeps/riscv/machine-gmon.h
@@ -0,0 +1,37 @@
+/* RISC-V definitions for profiling support.
+   Copyright (C) 1996-2018 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/>.  */
+
+/* Accept 'frompc' address as argument from the function that calls
+   _mcount for profiling.  Use  __builtin_return_address (0)
+   for the 'selfpc' address.  */
+
+#include <sysdep.h>
+
+static void mcount_internal (unsigned long int frompc,
+			     unsigned long int selfpc);
+
+#define _MCOUNT_DECL(frompc, selfpc) \
+static inline void mcount_internal (unsigned long int frompc, \
+unsigned long int selfpc)
+
+#define MCOUNT								\
+void _mcount (void *frompc)						\
+{									\
+  mcount_internal ((unsigned long int) frompc,				\
+		   (unsigned long int) RETURN_ADDRESS (0));		\
+}