gdb: Add OpenRISC or1k and or1knd target support

This patch prepares the current GDB port of the OpenRISC processor from
https://github.com/openrisc/binutils-gdb for upstream merging.

Testing has been done with a cgen sim provided in a separate patch. This
has been tested with 2 toolchains. GCC [1] 5.4.0 from the OpenRISC
project with Newlib [2] and GCC 5.4.0 with Musl [3] 1.1.4.

It supports or1knd (no delay slot target).
The default target is or1k (with delay slot).

You can change the target arch with:

(gdb) set architecture or1knd
The target architecture is assumed to be or1knd

[1] https://github.com/openrisc/or1k-gcc
[2] https://github.com/openrisc/newlib
[3] https://github.com/openrisc/musl-cross

gdb/doc/ChangeLog:

2017-12-12  Stafford Horne  <shorne@gmail.com>
	    Stefan Wallentowitz  <stefan@wallentowitz.de>
	    Franck Jullien  <franck.jullien@gmail.com>
	    Jeremy Bennett  <jeremy.bennett@embecosm.com>

	* gdb.texinfo: Add OpenRISC documentation.

gdb/ChangeLog:

2017-12-12  Stafford Horne  <shorne@gmail.com>
	    Stefan Wallentowitz  <stefan@wallentowitz.de>
	    Stefan Kristiansson  <stefan.kristiansson@saunalahti.fi>
	    Franck Jullien  <franck.jullien@gmail.com>
	    Jeremy Bennett  <jeremy.bennett@embecosm.com>

	* configure.tgt: Add targets for or1k and or1knd.
	* or1k-tdep.c: New file.
	* or1k-tdep.h: New file.
	* features/Makefile: Add or1k.xml to build.
	* features/or1k.xml: New file.
	* features/or1k-core.xml: New file.
	* features/or1k.c: Generated.

1 files changed, 56 insertions, 0 deletions

diff --git a/gdb/or1k-tdep.h b/gdb/or1k-tdep.h
new file mode 100644
index 00000000000..edcad886765
--- /dev/null
+++ b/gdb/or1k-tdep.h
@@ -0,0 +1,56 @@
+/* Definitions to target GDB to OpenRISC 1000 32-bit targets.
+   Copyright (C) 2008-2017 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/>.  */
+
+
+#ifndef OR1K_TDEP__H
+#define OR1K_TDEP__H
+
+#ifndef TARGET_OR1K
+#define TARGET_OR1K
+#endif
+
+#include "opcodes/or1k-desc.h"
+#include "opcodes/or1k-opc.h"
+
+/* General Purpose Registers */
+#define OR1K_ZERO_REGNUM          0
+#define OR1K_SP_REGNUM            1
+#define OR1K_FP_REGNUM            2
+#define OR1K_FIRST_ARG_REGNUM     3
+#define OR1K_LAST_ARG_REGNUM      8
+#define OR1K_LR_REGNUM            9
+#define OR1K_FIRST_SAVED_REGNUM  10
+#define OR1K_RV_REGNUM           11
+#define OR1K_PPC_REGNUM          (OR1K_MAX_GPR_REGS + 0)
+#define OR1K_NPC_REGNUM          (OR1K_MAX_GPR_REGS + 1)
+#define OR1K_SR_REGNUM           (OR1K_MAX_GPR_REGS + 2)
+
+/* Properties of the architecture. GDB mapping of registers is all the GPRs
+   and SPRs followed by the PPC, NPC and SR at the end. Red zone is the area
+   past the end of the stack reserved for exception handlers etc.  */
+
+#define OR1K_MAX_GPR_REGS            32
+#define OR1K_NUM_PSEUDO_REGS         0
+#define OR1K_NUM_REGS               (OR1K_MAX_GPR_REGS + 3)
+#define OR1K_STACK_ALIGN             4
+#define OR1K_INSTLEN                 4
+#define OR1K_INSTBITLEN             (OR1K_INSTLEN * 8)
+#define OR1K_NUM_TAP_RECORDS         8
+#define OR1K_FRAME_RED_ZONE_SIZE     2536
+
+#endif /* OR1K_TDEP__H */