arcv: Add support for riscv targets in nSIM setup.

Modified the nSIM setup logic to call setup_sim riscv when targeting
ARCV. It returns a simulator named with the target alias and a "-run"
suffix (for example, riscv64-unknown-elf-run), which can serve as a
wrapper for the simulator.

For non-ARCv targets, retain the previous behavior of setting the sim
board info directly.

Signed-off-by: Luis Silva <[email protected]>

Author: luismgsilva

dejagnu/baseboards/arc-sim-nsimdrv.exp

@@ -216,13 +216,9 @@ if {[check_target_arc64_64]} {
         -p nsim_isa_core=3 \
         -on nsim_isa_sat
 } elseif {[check_target_arcv]} {
-    set ext \
-        "-all.i.zicsr.zifencei.zihintpause.b.zca.zcb.zcmp.zcmt.a.m.zbb.zba.zbs"
-    lappend nsim_flags \
-        -p nsim_isa_family=rv32 \
-        -p nsim_isa_ext=${ext} \
-        -p nsim_semihosting=1 \
-        -off=enable_exceptions
+    # Not used.  The ARCV nSIM configuration is done through a wrapper.
+    # The simulator name is defined by "setup_sim riscv" which will be
+    # the target alias name with "-run" suffix. (e.g., riscv64-unknown-elf-run)
 } else {
     perror "Unknown CPU configuration"
 }
@@ -292,7 +288,11 @@ if {[info exists env(ARC_NSIM_OPTS) ]} {
 }
 
 # Setup nSIM.
-set_board_info sim "$nsim_bin [join $nsim_flags]"
+if {[check_target_arcv]} {
+    setup_sim riscv
+} else {
+    set_board_info sim "$nsim_bin [join $nsim_flags]"
+}
 # is_simulator should be set already by 'load_generic_config "sim"'. Do it here
 # to be safe.
 set_board_info is_simulator 1