[sim] cleanup GHDL scripts

sim/ghdl.sh

@@ -1,11 +1,46 @@
 #!/usr/bin/env bash
 
-# Abort if any command returns != 0
 set -e
 
 cd $(dirname "$0")
+GHDL="${GHDL:-ghdl}"
 
-echo "[TIP] Compile application with USER_FLAGS+=-DUART[0/1]_SIM_MODE to enable UART[0/1]'s simulation mode (redirect UART output to simulator console)."
+# Prepare UART SIM_MODE output files
+touch neorv32.uart0_sim_mode.out neorv32.uart1_sim_mode.out
+chmod 777 neorv32.uart0_sim_mode.out neorv32.uart1_sim_mode.out
 
-# Run simulation (pass down more than 1 parameter to GHDL)
-/bin/bash ghdl.run.sh $@
+# Prepare testbench UART log files
+touch neorv32_tb.uart0_rx.out neorv32_tb.uart1_rx.out
+chmod 777 neorv32_tb.uart0_rx.out neorv32_tb.uart1_rx.out
+
+# GHDL build directory
+mkdir -p build
+
+# GHDL import
+find ../rtl/core ../sim -type f -name '*.vhd'  -exec \
+  ghdl -i --std=08 --workdir=build --ieee=standard --work=neorv32 {} \;
+
+# GHDL analyze
+$GHDL -m --work=neorv32 --workdir=build --std=08 neorv32_tb
+
+# GHDL run parameters
+if [ -z "$1" ]
+  then
+    GHDL_RUN_ARGS="${@:---stop-time=10ms}"
+  else
+    # Let's pass down all the parameters to GHDL
+    GHDL_RUN_ARGS=$@
+fi
+echo "GHDL simulation run parameters: $GHDL_RUN_ARGS";
+
+# GHDL run
+runcmd="$GHDL -r --work=neorv32 --workdir=build --std=08 neorv32_tb \
+  --max-stack-alloc=0 \
+  --ieee-asserts=disable \
+  --assert-level=error $GHDL_RUN_ARGS"
+
+if [ -n "$GHDL_DEVNULL" ]; then
+  $runcmd >> /dev/null
+else
+  $runcmd
+fi