Add FreeBSD/riscv architecture.

Support for collecting and supplying general purpose and floating
point register sets is provided along with signal frame unwinding.

FreeBSD only supports RV64 currently, so while some provision is made
for RV32 in the general-purpose register set, the changes have only
been tested on RV64.

gdb/ChangeLog:

	* Makefile.in (ALL_TARGET_OBS): Add riscv-fbsd-tdep.o.
	(HFILES_NO_SRCDIR): Add riscv-fbsd-tdep.h.
	(ALLDEPFILES): Add riscv-fbsd-tdep.c.
	* NEWS: Mention new FreeBSD/riscv target.
	* configure.tgt: Add riscv*-*-freebsd*.
	* riscv-fbsd-tdep.c: New file.
	* riscv-fbsd-tdep.h: New file.

1 files changed, 33 insertions, 0 deletions

diff --git a/gdb/riscv-fbsd-tdep.h b/gdb/riscv-fbsd-tdep.h
new file mode 100644
index 00000000000..8b6abd565b9
--- /dev/null
+++ b/gdb/riscv-fbsd-tdep.h
@@ -0,0 +1,33 @@
+/* FreeBSD/riscv target support, prototypes.
+
+   Copyright (C) 2018 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "regset.h"
+
+/* The general-purpose regset consists of 31 X registers, EPC, and
+   SSTATUS.  */
+#define RISCV_FBSD_NUM_GREGS		33
+
+/* The fp regset always consists of 32 128-bit registers, plus a
+   64-bit CSR_FCSR.  If 'Q' is not supported, only the low 64-bits of
+   each floating point register are valid.  If 'D' is not supported,
+   only the low 32-bits of each floating point register are valid.  */
+#define RISCV_FBSD_SIZEOF_FPREGSET (32 * 16 + 8)
+
+extern const struct regset riscv_fbsd_gregset;
+extern const struct regset riscv_fbsd_fpregset;