checkpoint: VT1200 reverse-engineering workspace before board-model work

lat/notes/mapfuncs.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python3
+"""Map ROM string refs to enclosing functions in the unidasm output."""
+import bisect
+import re
+import struct
+
+ASM = "/tmp/opencode/v22.asm"
+ROM = "vt1200_v22.bin"
+ROM_BASE = 0x07E40000
+
+lines = []
+with open(ASM) as f:
+    for line in f:
+        head = line.split(":", 1)[0].strip()
+        try:
+            a = int(head, 16)
+        except ValueError:
+            continue
+        lines.append((a, line.rstrip("\n")))
+addrs = [a for a, _ in lines]
+
+# function prologues: MMTM SP, ... ; MOVE A14,A13
+entries = []
+for i, (a, t) in enumerate(lines):
+    if "MMTM   SP," in t:
+        # look ahead a few instructions for MOVE A14,A13
+        for j in range(i + 1, min(i + 4, len(lines))):
+            if "MOVE   A14,A13" in lines[j][1]:
+                entries.append(a)
+                break
+
+print(f"{len(entries)} function entries (MMTM prologue)")
+
+
+def enclosing(bitaddr):
+    i = bisect.bisect_right(entries, bitaddr) - 1
+    return entries[i] if i >= 0 else None
+
+
+def main():
+    image = open(ROM, "rb").read()
+    pat = re.compile(r"DMUL|DMUX|demultiplex|Illegal slot|service class|"
+                     r"STOP_SLOT|ATTN|DATA_B|Data_A|host_credits|Multiplex|"
+                     r"insert_latjob|LAT_CREATE|LAT_CLOSE|LAT_SEND|lat session|"
+                     r"slot|extinct|circuit|Circuit|Calloc")
+    for m in re.finditer(rb"[\x20-\x7e]{4,}", image):
+        s = m.group().decode("latin1")
+        if not pat.search(s):
+            continue
+        off = m.start()
+        val = (ROM_BASE + off) << 3
+        p = struct.pack("<I", val)
+        start = 0
+        refs = []
+        while True:
+            i = image.find(p, start)
+            if i < 0:
+                break
+            refs.append(i * 8)
+            start = i + 1
+        if not refs:
+            continue
+        for r in refs:
+            e = enclosing(r)
+            print(f"func 0x{(e or 0)//8:06X}  ref 0x{r//8:06X}  str 0x{off:06X}  {s!r}")
+
+
+if __name__ == "__main__":
+    main()