Introduce ARCv2 tcl config files

With this commit we add tcl files which describes
ARCv2 architecture features and configure files
for ARCv2 EMSK board.

Changes since v1:
-Moved from http://openocd.zylin.com/#/c/5332/4
 into separate commit.

Changes:
22.01.2020:
-Removed "actionpoints" handling code in
 tcl/cpu/arc/v2.tcl because this capability
 is not supported yet.

Changes:
17.03.2020:
-Update Licence headers
-Cleanup indents
-Removed "reset halt" in boards .tcl
-Updated adapter frequency commands

Changes:
15.03.2020:
-Removed "init" in the of boards .tcl

Change-Id: I51bf620abe7b8e046e1dccc861a7d963965d3a42
Signed-off-by: Evgeniy Didin <didin@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Reviewed-on: http://openocd.zylin.com/5350
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>

tcl/cpu/arc/common.tcl

@@ -0,0 +1,40 @@
+#  Copyright (C) 2015, 2020 Synopsys, Inc.
+#  Anton Kolesov <anton.kolesov@synopsys.com>
+#  Didin Evgeniy <didin@synopsys.com>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Things common to all ARCs
+
+# It is assumed that target is already halted.
+proc arc_common_reset { {target ""} } {
+        if { $target != "" } {
+                targets $target
+        }
+
+        halt
+
+        # 1. Interrupts are disabled (STATUS32.IE)
+        # 2. The status register flags are cleared.
+        # All fields, except the H bit, are set to 0 when the processor is Reset.
+
+        arc jtag set-aux-reg 0xA 0x1
+
+        # 3. The loop count, loop start, and loop end registers are cleared.
+        arc jtag set-core-reg 60 0
+        arc jtag set-aux-reg 0x2 0
+        arc jtag set-aux-reg 0x3 0
+
+        # Program execution begins at the address referenced by the four byte reset
+        # vector located at the interrupt vector base address, which is the first
+        # entry (offset 0x00) in the vector table.
+        set int_vector_base [arc jtag get-aux-reg 0x25]
+        set start_pc ""
+        mem2array start_pc 32 $int_vector_base 1
+        arc jtag set-aux-reg 0x6 $start_pc(0)
+
+        # It is OK to do uncached writes - register cache will be invalidated by
+        # the reset_assert() function.
+}
+
+# vim:expandtab: