From a5427d704a9620b7ebbf552523141dcc4604d199 Mon Sep 17 00:00:00 2001
From: Chris Baker <chris.l.baker@gmail.com>
Date: Sun, 21 Apr 2024 14:17:05 -0400
Subject: [PATCH 1/2] icebox_vlog: use proper Verilog-2001 module declarations

Resolves #328
Summary:
- By default emit Verilog-2001 style module declarations with direction
  and signal type defined in the module prototype and not in the body of
  the module
- Add -C option to output Verilog-1995 module declarations for
  compatibility with older toolchains
- Add some comments to the file to assist future maintainers

Background:
Currently, icebox_vlog outputs a mixed-style module declaration in which
it puts the port direction in the module prototype and later declares
the signals as ports or wires.
```verilog
module chip (input pin1, output pin2);

wire pin1;
reg pin2 = 0;
```

The inclusion of the direction in the module prototype is a feature of
newer Verilog-2001 specification.

It seems probable that older versions of Icarus Verilog had some leeway
in handling this mixed-style of declaration. But, it seems that at least
the version included in newer Ubuntu distributions considers this to be
a syntax error.

In this commit, the module declaration above will be emitted as:
```verilog
module chip (input wire pin1, output reg pin2 = 0);
```

Or if you sepcificy the -C option for Verilog-1995 compatibility:
```verilog
module chip (pin1, pin2);
input pin1;
output pin2;

wire pin1;
reg pin2 = 0;
```
---
 icebox/icebox_vlog.py | 129 ++++++++++++++++++++++++++++++++----------
 1 file changed, 99 insertions(+), 30 deletions(-)

diff --git a/icebox/icebox_vlog.py b/icebox/icebox_vlog.py
index 74ac3d3dac..0fb272d10d 100755
--- a/icebox/icebox_vlog.py
+++ b/icebox/icebox_vlog.py
@@ -26,6 +26,7 @@
 check_driver = False
 lookup_symbols = False
 do_collect = False
+v95_compatibility = False
 package = None
 pcf_data = dict()
 portnames = set()
@@ -70,11 +71,14 @@ def usage():
 
     -D
         enable exactly-one-driver checks
+
+    -C
+        use old Verilog-1995 module declarations (for compatibility)
 """ % os.path.basename(sys.argv[0]))
     sys.exit(0)
 
 try:
-    opts, args = getopt.getopt(sys.argv[1:], "sSlLap:P:n:d:cRD")
+    opts, args = getopt.getopt(sys.argv[1:], "sSlLap:P:n:d:cRDC")
 except:
     usage()
 
@@ -125,6 +129,8 @@ def usage():
         check_ieren = True
     elif o == "-D":
         check_driver = True
+    elif o == "-C":
+        v95_compatibility = True
     else:
         usage()
 
@@ -140,8 +146,11 @@ def usage():
 ic.read_file(args[0])
 print()
 
-text_wires = list()
-text_ports = list()
+# these variables store text representations that will end up printed to the
+# output to create the body of the verilog file
+text_wires = list() # all wires in the body of the module
+text_ports = list() # all ports in the module declaration
+v95_module_text_ports = list() # port signal declarations without decoration
 
 luts_queue = set()
 special_5k_queue = set()
@@ -870,58 +879,118 @@ def make_lut_expr(bits, sigs):
     text_func.append("assign %-*s = %s;" % (max_net_len, a[0], a[1]))
 
 if do_collect:
-    new_text_ports = set()
+    new_text_ports = list()
     vec_ports_min = dict()
     vec_ports_max = dict()
     vec_ports_dir = dict()
     for port in text_ports:
+        # find ports with [x] subscripts to combine into [a:b] style busses
         match = re_match_cached(r"(input|output|inout) (.*)\[(\d+)\] ?$", port);
         if match:
             vec_ports_min[match.group(2)] = min(vec_ports_min.setdefault(match.group(2), int(match.group(3))), int(match.group(3)))
             vec_ports_max[match.group(2)] = max(vec_ports_max.setdefault(match.group(2), int(match.group(3))), int(match.group(3)))
             vec_ports_dir[match.group(2)] = match.group(1)
         else:
-            new_text_ports.add(port)
+            new_text_ports.append(port)
+            if v95_compatibility:
+                # strip direction from text used in module declaration
+                port=str(port.split()[-1:][0])
+                v95_module_text_ports.append("%s%s" % (port, ' ' if port.startswith("\\") else ''))
     for port, direct in list(vec_ports_dir.items()):
         min_idx = vec_ports_min[port]
         max_idx = vec_ports_max[port]
-        new_text_ports.add("%s [%d:%d] %s " % (direct, max_idx, min_idx, port))
-    text_ports = list(new_text_ports)
-
-print("module %s (%s);\n" % (modname, ", ".join(text_ports)))
-
-new_text_wires = list()
-new_text_regs = list()
-new_text_raw = list()
-for line in text_wires:
+        new_text_ports.append("%s wire [%d:%d] %s " % (direct, max_idx, min_idx, port))
+        if v95_compatibility:
+            # strip direction and dimensions from text used in module declaration
+            v95_module_text_ports.append("%s%s" % (port, ' ' if port.startswith("\\") else ''))
+    text_ports = new_text_ports
+
+if not do_collect:
+    if v95_compatibility:
+        # strip direction from from text used in module declaration
+        for port in text_ports:
+            port=str(port.split()[-1:][0])
+            v95_module_text_ports.append("%s%s" % (port, ' ' if port.startswith("\\") else ''))
+
+# these variables used to normalize/filter the output
+new_text_wires = list() # list of wire names to declare at top of module
+new_text_regs = list() # list of reg names to declare at top of module
+new_text_raw = list() # remaining content not moved to previous 2 variables
+vec_ports_type = dict() # track which ports should be reg vs wire
+temp_flat_ports = " ".join(text_ports) # temp variable
+
+for line in text_wires: #note - continue in loop body (twice)
+    # match wire declarations (not comments, assigns, etc)
     match = re_match_cached(r"wire ([^ ;]+)(.*)", line)
     if match:
+        name = match.group(1)
+        lineend = match.group(2)
+        isreg = (name in wire_to_reg)
+        isport = (name in temp_flat_ports)
+        if not v95_compatibility and isport:
+            # find the port declration and store off its type
+            for port in text_ports: #note - break in loop body
+                if name in port:
+                    vec_ports_type[port] = "reg" if isreg else "wire"
+                    break # break inner loop when any match found
+            continue # continue outer loop
         if strip_comments:
-            name = match.group(1)
+            # strip_comments will also compact reg and wire declarations
+            # 10 per line with comma separation
+            # names starting with \ can't immediately have a comma after them
+            # so insert a space in the name
+            proper_name = name
             if name.startswith("\\"):
-                name += " "
-            if match.group(1) in wire_to_reg:
-                new_text_regs.append(name)
+                proper_name += " "
+            if isreg:
+                new_text_regs.append(proper_name)
             else:
-                new_text_wires.append(name)
-            continue
+                new_text_wires.append(proper_name)
+            continue # continue outer loop
         else:
-            if match.group(1) in wire_to_reg:
-                line = "reg " + match.group(1) + " = 0" + match.group(2)
-    if strip_comments:
-        new_text_raw.append(line)
-    else:
-        print(line)
-for names in [new_text_wires[x:x+10] for x in range(0, len(new_text_wires), 10)]:
-    print("wire %s;" % ", ".join(names))
-for names in [new_text_regs[x:x+10] for x in range(0, len(new_text_regs), 10)]:
-    print("reg %s = 0;" % " = 0, ".join(names))
+            if isreg:
+                line = "reg " + name + " = 0" + lineend
+    new_text_raw.append(line)
+
+# BEGIN PRINTING THE VERILOG OUTPUT
+# print the module declaration
+if not v95_compatibility:
+    print("module %s (" % modname, end='');
+    separator = ""
+    for port in text_ports:
+        iotype = vec_ports_type.get(port)
+        if iotype:
+            # insert the reg/wire designator after the port direction
+            port = port.replace(" ", " %s " % iotype, 1)
+        print("%s%s%s" % (separator, port, " = 0" if "reg"==iotype else ""), end='')
+        separator=", "
+    print(");\n")
+else:
+    # use v95_module_text_ports with stripped metadata
+    print("module %s (%s);" % (modname, ", ".join(v95_module_text_ports)))
+    # print verbose port declaration on lines after the module declaration
+    for line in text_ports:
+        print(line, end=";\n")
+    print()
+
+# print module body
 if strip_comments:
+    for names in [new_text_wires[x:x+10] for x in range(0, len(new_text_wires), 10)]:
+        print("wire %s;" % ", ".join(names))
+    for names in [new_text_regs[x:x+10] for x in range(0, len(new_text_regs), 10)]:
+        print("reg %s = 0;" % " = 0, ".join(names))
     for line in new_text_raw:
         print(line)
     print()
+else:
+    for line in new_text_raw:
+        print(line)
 
 if do_collect:
+    # when collecing ports into busses, the module declaration is changed to
+    # create a bus interface as a wire
+    # individual component signals may be wire or reg, so assign the signals
+    # to the bus port here
     for port, direct in list(vec_ports_dir.items()):
         min_idx = vec_ports_min[port]
         max_idx = vec_ports_max[port]

From 95990fb2fc611ca019f4547b21f70ee743030017 Mon Sep 17 00:00:00 2001
From: Chris Baker <chris.l.baker@gmail.com>
Date: Sun, 21 Apr 2024 15:15:08 -0400
Subject: [PATCH 2/2] icebox_vlog: add basic test cases

Makefile provides various targets for testing icebox_vlog.
- %_syn.v targets will use icebox_vlog to generate a .v file from
  the blinky.asc file
- %_syntb targets will invoke iverilog on the .v files
- %.json targets will invoke yosys on the .v files
- test target will attempt several combinations of command line options
  for icebox_vlog (all combinations of -s, -l, -p, -c, -C) and will then
  trigger iverilog and yosys targets to attempt parsing the .v files

Output files generated by `make test` can be compared after making code
changes to icebox_vlog.py to identify any regressions.
---
 icebox/testcase/.gitignore         |  8 ++++
 icebox/testcase/Makefile           | 73 ++++++++++++++++++++++++++++++
 icebox/testcase/blinky-C_stb.v     |  1 +
 icebox/testcase/blinky-Cc_stb.v    |  1 +
 icebox/testcase/blinky-Ccp_stb.v   |  1 +
 icebox/testcase/blinky-Cl_stb.v    |  1 +
 icebox/testcase/blinky-Clc_stb.v   |  1 +
 icebox/testcase/blinky-Clcp_stb.v  |  1 +
 icebox/testcase/blinky-Clp_stb.v   |  1 +
 icebox/testcase/blinky-Cp_stb.v    |  1 +
 icebox/testcase/blinky-Cs_stb.v    |  1 +
 icebox/testcase/blinky-Csc_stb.v   |  1 +
 icebox/testcase/blinky-Cscp_stb.v  |  1 +
 icebox/testcase/blinky-Csl_stb.v   |  1 +
 icebox/testcase/blinky-Cslc_stb.v  |  1 +
 icebox/testcase/blinky-Cslcp_stb.v |  1 +
 icebox/testcase/blinky-Cslp_stb.v  |  1 +
 icebox/testcase/blinky-Csp_stb.v   |  1 +
 icebox/testcase/blinky-c_stb.v     | 35 ++++++++++++++
 icebox/testcase/blinky-cp_stb.v    |  1 +
 icebox/testcase/blinky-l_stb.v     | 35 ++++++++++++++
 icebox/testcase/blinky-lc_stb.v    |  1 +
 icebox/testcase/blinky-lcp_stb.v   |  1 +
 icebox/testcase/blinky-lp_stb.v    |  1 +
 icebox/testcase/blinky-p_stb.v     | 35 ++++++++++++++
 icebox/testcase/blinky-s_stb.v     |  1 +
 icebox/testcase/blinky-sc_stb.v    |  1 +
 icebox/testcase/blinky-scp_stb.v   |  1 +
 icebox/testcase/blinky-sl_stb.v    |  1 +
 icebox/testcase/blinky-slc_stb.v   |  1 +
 icebox/testcase/blinky-slcp_stb.v  |  1 +
 icebox/testcase/blinky-slp_stb.v   |  1 +
 icebox/testcase/blinky-sp_stb.v    |  1 +
 icebox/testcase/blinky.pcf         |  9 ++++
 icebox/testcase/blinky.v           | 23 ++++++++++
 icebox/testcase/blinky_stb.v       |  1 +
 icebox/testcase/blinky_tb.v        | 31 +++++++++++++
 37 files changed, 278 insertions(+)
 create mode 100644 icebox/testcase/.gitignore
 create mode 100644 icebox/testcase/Makefile
 create mode 120000 icebox/testcase/blinky-C_stb.v
 create mode 120000 icebox/testcase/blinky-Cc_stb.v
 create mode 120000 icebox/testcase/blinky-Ccp_stb.v
 create mode 120000 icebox/testcase/blinky-Cl_stb.v
 create mode 120000 icebox/testcase/blinky-Clc_stb.v
 create mode 120000 icebox/testcase/blinky-Clcp_stb.v
 create mode 120000 icebox/testcase/blinky-Clp_stb.v
 create mode 120000 icebox/testcase/blinky-Cp_stb.v
 create mode 120000 icebox/testcase/blinky-Cs_stb.v
 create mode 120000 icebox/testcase/blinky-Csc_stb.v
 create mode 120000 icebox/testcase/blinky-Cscp_stb.v
 create mode 120000 icebox/testcase/blinky-Csl_stb.v
 create mode 120000 icebox/testcase/blinky-Cslc_stb.v
 create mode 120000 icebox/testcase/blinky-Cslcp_stb.v
 create mode 120000 icebox/testcase/blinky-Cslp_stb.v
 create mode 120000 icebox/testcase/blinky-Csp_stb.v
 create mode 100644 icebox/testcase/blinky-c_stb.v
 create mode 120000 icebox/testcase/blinky-cp_stb.v
 create mode 100644 icebox/testcase/blinky-l_stb.v
 create mode 120000 icebox/testcase/blinky-lc_stb.v
 create mode 120000 icebox/testcase/blinky-lcp_stb.v
 create mode 120000 icebox/testcase/blinky-lp_stb.v
 create mode 100644 icebox/testcase/blinky-p_stb.v
 create mode 120000 icebox/testcase/blinky-s_stb.v
 create mode 120000 icebox/testcase/blinky-sc_stb.v
 create mode 120000 icebox/testcase/blinky-scp_stb.v
 create mode 120000 icebox/testcase/blinky-sl_stb.v
 create mode 120000 icebox/testcase/blinky-slc_stb.v
 create mode 120000 icebox/testcase/blinky-slcp_stb.v
 create mode 120000 icebox/testcase/blinky-slp_stb.v
 create mode 120000 icebox/testcase/blinky-sp_stb.v
 create mode 100644 icebox/testcase/blinky.pcf
 create mode 100644 icebox/testcase/blinky.v
 create mode 120000 icebox/testcase/blinky_stb.v
 create mode 100644 icebox/testcase/blinky_tb.v

diff --git a/icebox/testcase/.gitignore b/icebox/testcase/.gitignore
new file mode 100644
index 0000000000..3e8c983312
--- /dev/null
+++ b/icebox/testcase/.gitignore
@@ -0,0 +1,8 @@
+*.asc
+*.json
+*_tb
+*_syntb
+*_syn.v
+*.vcd
+*.rpt
+*.bin
diff --git a/icebox/testcase/Makefile b/icebox/testcase/Makefile
new file mode 100644
index 0000000000..4c96405729
--- /dev/null
+++ b/icebox/testcase/Makefile
@@ -0,0 +1,73 @@
+PROJ = blinky
+
+PIN_DEF = blinky.pcf
+DEVICE = hx1k
+PACKAGE = tq144
+icebox_vlog_test_params := s l p c sl sp sc lp lc cp slp slc scp lcp slcp
+
+all: test
+
+test: icebox_vlog_test
+
+# Create test target list for icebox_vlog with different parameter options
+# composed of the case with no options, all of the options specified in
+# $(icebox_vlog_test_params), and all of the same cases with -C (Verilog-1995)
+# compatibilty.
+icebox_vlog_output := $(PROJ)_syn.v $(PROJ)-C_syn.v \
+	$(foreach case,$(icebox_vlog_test_params),$(PROJ)-$(case)_syn.v) \
+	$(foreach case,$(icebox_vlog_test_params),$(PROJ)-C$(case)_syn.v)
+icebox_vlog_iverilog_testlist := $(PROJ)_syntb $(PROJ)-C_syntb \
+	$(foreach case,$(icebox_vlog_test_params),$(PROJ)-$(case)_syntb) \
+	$(foreach case,$(icebox_vlog_test_params),$(PROJ)-C$(case)_syntb)
+icebox_vlog_yosys_testlist := $(PROJ)_syn.json $(PROJ)-C_syn.json \
+	$(foreach case,$(icebox_vlog_test_params),$(PROJ)-$(case)_syn.json) \
+	$(foreach case,$(icebox_vlog_test_params),$(PROJ)-C$(case)_syn.json)
+icebox_vlog_test: $(icebox_vlog_output) $(icebox_vlog_iverilog_testlist) $(icebox_vlog_yosys_testlist)
+
+%.json: %.v
+	yosys -p 'synth_ice40 -top $(PROJ) -json $@' $<
+
+%.asc: $(PIN_DEF) %.json
+	nextpnr-ice40 --$(DEVICE) --package $(PACKAGE) --asc $@ --pcf $< --json $*.json
+
+%.bin: %.asc
+	icepack $< $@
+
+%.rpt: %.asc
+	icetime -d $(DEVICE) -mtr $@ $<
+
+%_tb: %_tb.v %.v
+	iverilog -o $@ $^
+
+%_tb.vcd: %_tb
+	vvp -N $< +vcd=$@
+
+get_test_params = $(subst p,p $(PIN_DEF),\
+	$(filter-out $(1),\
+	$(1:$(PROJ)-%_syn.v=-%)))
+%_syn.v: $(PROJ).asc
+	../icebox_vlog.py -n blinky $(call get_test_params,$@) $^ > $@
+
+%_syntb: %_stb.v %_syn.v
+	iverilog -o $@ $^
+
+%_syntb.vcd: %_syntb
+	vvp -N $< +vcd=$@
+
+sim: $(PROJ)_tb.vcd
+
+postsim: $(PROJ)_syntb.vcd
+
+prog: $(PROJ).bin
+	iceprog $<
+
+sudo-prog: $(PROJ).bin
+	@echo 'Executing prog as root!!!'
+	sudo iceprog $<
+
+clean:
+	rm -f *.json $(PROJ).asc $(PROJ).rpt $(PROJ).bin \
+		*.vcd *_tb *_syntb *_syn.v
+
+.SECONDARY:
+.PHONY: all prog clean test icebox_vlog_test
diff --git a/icebox/testcase/blinky-C_stb.v b/icebox/testcase/blinky-C_stb.v
new file mode 120000
index 0000000000..6d0e1f0d81
--- /dev/null
+++ b/icebox/testcase/blinky-C_stb.v
@@ -0,0 +1 @@
+blinky_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Cc_stb.v b/icebox/testcase/blinky-Cc_stb.v
new file mode 120000
index 0000000000..6d0e1f0d81
--- /dev/null
+++ b/icebox/testcase/blinky-Cc_stb.v
@@ -0,0 +1 @@
+blinky_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Ccp_stb.v b/icebox/testcase/blinky-Ccp_stb.v
new file mode 120000
index 0000000000..0f7fb4462f
--- /dev/null
+++ b/icebox/testcase/blinky-Ccp_stb.v
@@ -0,0 +1 @@
+blinky_tb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Cl_stb.v b/icebox/testcase/blinky-Cl_stb.v
new file mode 120000
index 0000000000..5aba7026d7
--- /dev/null
+++ b/icebox/testcase/blinky-Cl_stb.v
@@ -0,0 +1 @@
+blinky-l_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Clc_stb.v b/icebox/testcase/blinky-Clc_stb.v
new file mode 120000
index 0000000000..5aba7026d7
--- /dev/null
+++ b/icebox/testcase/blinky-Clc_stb.v
@@ -0,0 +1 @@
+blinky-l_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Clcp_stb.v b/icebox/testcase/blinky-Clcp_stb.v
new file mode 120000
index 0000000000..0f7fb4462f
--- /dev/null
+++ b/icebox/testcase/blinky-Clcp_stb.v
@@ -0,0 +1 @@
+blinky_tb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Clp_stb.v b/icebox/testcase/blinky-Clp_stb.v
new file mode 120000
index 0000000000..bddaa97603
--- /dev/null
+++ b/icebox/testcase/blinky-Clp_stb.v
@@ -0,0 +1 @@
+blinky-p_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Cp_stb.v b/icebox/testcase/blinky-Cp_stb.v
new file mode 120000
index 0000000000..bddaa97603
--- /dev/null
+++ b/icebox/testcase/blinky-Cp_stb.v
@@ -0,0 +1 @@
+blinky-p_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Cs_stb.v b/icebox/testcase/blinky-Cs_stb.v
new file mode 120000
index 0000000000..6d0e1f0d81
--- /dev/null
+++ b/icebox/testcase/blinky-Cs_stb.v
@@ -0,0 +1 @@
+blinky_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Csc_stb.v b/icebox/testcase/blinky-Csc_stb.v
new file mode 120000
index 0000000000..6d0e1f0d81
--- /dev/null
+++ b/icebox/testcase/blinky-Csc_stb.v
@@ -0,0 +1 @@
+blinky_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Cscp_stb.v b/icebox/testcase/blinky-Cscp_stb.v
new file mode 120000
index 0000000000..0f7fb4462f
--- /dev/null
+++ b/icebox/testcase/blinky-Cscp_stb.v
@@ -0,0 +1 @@
+blinky_tb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Csl_stb.v b/icebox/testcase/blinky-Csl_stb.v
new file mode 120000
index 0000000000..5aba7026d7
--- /dev/null
+++ b/icebox/testcase/blinky-Csl_stb.v
@@ -0,0 +1 @@
+blinky-l_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Cslc_stb.v b/icebox/testcase/blinky-Cslc_stb.v
new file mode 120000
index 0000000000..5aba7026d7
--- /dev/null
+++ b/icebox/testcase/blinky-Cslc_stb.v
@@ -0,0 +1 @@
+blinky-l_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Cslcp_stb.v b/icebox/testcase/blinky-Cslcp_stb.v
new file mode 120000
index 0000000000..0f7fb4462f
--- /dev/null
+++ b/icebox/testcase/blinky-Cslcp_stb.v
@@ -0,0 +1 @@
+blinky_tb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Cslp_stb.v b/icebox/testcase/blinky-Cslp_stb.v
new file mode 120000
index 0000000000..bddaa97603
--- /dev/null
+++ b/icebox/testcase/blinky-Cslp_stb.v
@@ -0,0 +1 @@
+blinky-p_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-Csp_stb.v b/icebox/testcase/blinky-Csp_stb.v
new file mode 120000
index 0000000000..bddaa97603
--- /dev/null
+++ b/icebox/testcase/blinky-Csp_stb.v
@@ -0,0 +1 @@
+blinky-p_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-c_stb.v b/icebox/testcase/blinky-c_stb.v
new file mode 100644
index 0000000000..c40375cdb1
--- /dev/null
+++ b/icebox/testcase/blinky-c_stb.v
@@ -0,0 +1,35 @@
+// From nextpnr:ice40/examples/blinky
+// Original file due to Claire Xenia Wolf
+
+module blinky_tb;
+    reg clk;
+    always #5 clk = (clk === 1'b0);
+
+    wire led1, led2, led3, led4, led5;
+
+    blinky uut (
+        .io_0_8_1(clk),
+        .io_13_12_1(led1),
+        .io_13_12_0(led2),
+        .io_13_11_1(led3),
+        .io_13_11_0(led4),
+        .io_13_9_1(led5)
+    );
+
+    reg [4095:0] vcdfile;
+
+    initial begin
+        if ($value$plusargs("vcd=%s", vcdfile)) begin
+            $dumpfile(vcdfile);
+            $dumpvars(0, blinky_tb);
+        end
+    end
+
+    initial begin
+        repeat (10) begin
+            repeat (900000) @(posedge clk);
+            $display(led1, led2, led3, led4, led5);
+        end
+        $finish;
+    end
+endmodule
diff --git a/icebox/testcase/blinky-cp_stb.v b/icebox/testcase/blinky-cp_stb.v
new file mode 120000
index 0000000000..0f7fb4462f
--- /dev/null
+++ b/icebox/testcase/blinky-cp_stb.v
@@ -0,0 +1 @@
+blinky_tb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-l_stb.v b/icebox/testcase/blinky-l_stb.v
new file mode 100644
index 0000000000..b2c4f01546
--- /dev/null
+++ b/icebox/testcase/blinky-l_stb.v
@@ -0,0 +1,35 @@
+// From nextpnr:ice40/examples/blinky
+// Original file due to Claire Xenia Wolf
+
+module blinky_tb;
+    reg clk;
+    always #5 clk = (clk === 1'b0);
+
+    wire led1, led2, led3, led4, led5;
+
+    blinky uut (
+        .pin_21(clk),
+        .pin_95(led1),
+        .pin_96(led2),
+        .pin_97(led3),
+        .pin_98(led4),
+        .pin_99(led5)
+    );
+
+    reg [4095:0] vcdfile;
+
+    initial begin
+        if ($value$plusargs("vcd=%s", vcdfile)) begin
+            $dumpfile(vcdfile);
+            $dumpvars(0, blinky_tb);
+        end
+    end
+
+    initial begin
+        repeat (10) begin
+            repeat (900000) @(posedge clk);
+            $display(led1, led2, led3, led4, led5);
+        end
+        $finish;
+    end
+endmodule
diff --git a/icebox/testcase/blinky-lc_stb.v b/icebox/testcase/blinky-lc_stb.v
new file mode 120000
index 0000000000..5aba7026d7
--- /dev/null
+++ b/icebox/testcase/blinky-lc_stb.v
@@ -0,0 +1 @@
+blinky-l_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-lcp_stb.v b/icebox/testcase/blinky-lcp_stb.v
new file mode 120000
index 0000000000..0f7fb4462f
--- /dev/null
+++ b/icebox/testcase/blinky-lcp_stb.v
@@ -0,0 +1 @@
+blinky_tb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-lp_stb.v b/icebox/testcase/blinky-lp_stb.v
new file mode 120000
index 0000000000..bddaa97603
--- /dev/null
+++ b/icebox/testcase/blinky-lp_stb.v
@@ -0,0 +1 @@
+blinky-p_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-p_stb.v b/icebox/testcase/blinky-p_stb.v
new file mode 100644
index 0000000000..564b1717c1
--- /dev/null
+++ b/icebox/testcase/blinky-p_stb.v
@@ -0,0 +1,35 @@
+// From nextpnr:ice40/examples/blinky
+// Original file due to Claire Xenia Wolf
+
+module blinky_tb;
+    reg clk;
+    always #5 clk = (clk === 1'b0);
+
+    wire led1, led2, led3, led4, led5;
+
+    blinky uut (
+        .clki (clk),
+        .\led[0] (led1),
+        .\led[1] (led2),
+        .\led[2] (led3),
+        .\led[3] (led4),
+        .\led[4] (led5)
+    );
+
+    reg [4095:0] vcdfile;
+
+    initial begin
+        if ($value$plusargs("vcd=%s", vcdfile)) begin
+            $dumpfile(vcdfile);
+            $dumpvars(0, blinky_tb);
+        end
+    end
+
+    initial begin
+        repeat (10) begin
+            repeat (900000) @(posedge clk);
+            $display(led1, led2, led3, led4, led5);
+        end
+        $finish;
+    end
+endmodule
diff --git a/icebox/testcase/blinky-s_stb.v b/icebox/testcase/blinky-s_stb.v
new file mode 120000
index 0000000000..6d0e1f0d81
--- /dev/null
+++ b/icebox/testcase/blinky-s_stb.v
@@ -0,0 +1 @@
+blinky_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-sc_stb.v b/icebox/testcase/blinky-sc_stb.v
new file mode 120000
index 0000000000..6d0e1f0d81
--- /dev/null
+++ b/icebox/testcase/blinky-sc_stb.v
@@ -0,0 +1 @@
+blinky_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-scp_stb.v b/icebox/testcase/blinky-scp_stb.v
new file mode 120000
index 0000000000..0f7fb4462f
--- /dev/null
+++ b/icebox/testcase/blinky-scp_stb.v
@@ -0,0 +1 @@
+blinky_tb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-sl_stb.v b/icebox/testcase/blinky-sl_stb.v
new file mode 120000
index 0000000000..5aba7026d7
--- /dev/null
+++ b/icebox/testcase/blinky-sl_stb.v
@@ -0,0 +1 @@
+blinky-l_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-slc_stb.v b/icebox/testcase/blinky-slc_stb.v
new file mode 120000
index 0000000000..5aba7026d7
--- /dev/null
+++ b/icebox/testcase/blinky-slc_stb.v
@@ -0,0 +1 @@
+blinky-l_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-slcp_stb.v b/icebox/testcase/blinky-slcp_stb.v
new file mode 120000
index 0000000000..0f7fb4462f
--- /dev/null
+++ b/icebox/testcase/blinky-slcp_stb.v
@@ -0,0 +1 @@
+blinky_tb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-slp_stb.v b/icebox/testcase/blinky-slp_stb.v
new file mode 120000
index 0000000000..bddaa97603
--- /dev/null
+++ b/icebox/testcase/blinky-slp_stb.v
@@ -0,0 +1 @@
+blinky-p_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky-sp_stb.v b/icebox/testcase/blinky-sp_stb.v
new file mode 120000
index 0000000000..bddaa97603
--- /dev/null
+++ b/icebox/testcase/blinky-sp_stb.v
@@ -0,0 +1 @@
+blinky-p_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky.pcf b/icebox/testcase/blinky.pcf
new file mode 100644
index 0000000000..42d205a317
--- /dev/null
+++ b/icebox/testcase/blinky.pcf
@@ -0,0 +1,9 @@
+# From nextpnr:ice40/examples/blinky
+# Original file due to David Shah
+
+set_io led[0] 99
+set_io led[1] 98
+set_io led[2] 97
+set_io led[3] 96
+set_io led[4] 95
+set_io clki 21
diff --git a/icebox/testcase/blinky.v b/icebox/testcase/blinky.v
new file mode 100644
index 0000000000..e31c87318a
--- /dev/null
+++ b/icebox/testcase/blinky.v
@@ -0,0 +1,23 @@
+// From nextpnr:ice40/examples/blinky
+// Original file due to Claire Xenia Wolf
+
+module blinky (
+    input  clki,
+    output [4:0] led
+);
+
+    assign clk = clki;
+
+    localparam BITS = 5;
+    localparam LOG2DELAY = 21;
+
+    reg [BITS+LOG2DELAY-1:0] counter = 0;
+    reg [BITS-1:0] outcnt;
+
+    always @(posedge clk) begin
+        counter <= counter + 1;
+        outcnt <= counter >> LOG2DELAY;
+    end
+
+    assign led = outcnt ^ (outcnt >> 1);
+endmodule
diff --git a/icebox/testcase/blinky_stb.v b/icebox/testcase/blinky_stb.v
new file mode 120000
index 0000000000..4f93d11e5c
--- /dev/null
+++ b/icebox/testcase/blinky_stb.v
@@ -0,0 +1 @@
+blinky-c_stb.v
\ No newline at end of file
diff --git a/icebox/testcase/blinky_tb.v b/icebox/testcase/blinky_tb.v
new file mode 100644
index 0000000000..f0b764e72e
--- /dev/null
+++ b/icebox/testcase/blinky_tb.v
@@ -0,0 +1,31 @@
+// From nextpnr:ice40/examples/blinky
+// Original file due to Claire Xenia Wolf
+
+module blinky_tb;
+    reg clk;
+    always #5 clk = (clk === 1'b0);
+
+    wire led1, led2, led3, led4, led5;
+
+    blinky uut (
+        .clki (clk),
+        .\led ({led1, led2, led3, led4, led5})
+    );
+
+    reg [4095:0] vcdfile;
+
+    initial begin
+        if ($value$plusargs("vcd=%s", vcdfile)) begin
+            $dumpfile(vcdfile);
+            $dumpvars(0, blinky_tb);
+        end
+    end
+
+    initial begin
+        repeat (10) begin
+            repeat (900000) @(posedge clk);
+            $display(led1, led2, led3, led4, led5);
+        end
+        $finish;
+    end
+endmodule