From c318400b94731114d7d7dc49b5dd692b494c63bf Mon Sep 17 00:00:00 2001
From: uvok
Date: Sun, 4 Jan 2026 17:29:31 +0100
Subject: finish disassembler

---
 nandgame/assembler/disas.py | 55 +++++++++++++++++++++++++++------------------
 1 file changed, 33 insertions(+), 22 deletions(-)

(limited to 'nandgame/assembler')

diff --git a/nandgame/assembler/disas.py b/nandgame/assembler/disas.py
index 21cd081..65e4a2c 100755
--- a/nandgame/assembler/disas.py
+++ b/nandgame/assembler/disas.py
@@ -7,7 +7,7 @@ def decode_jump(ins: int) -> str:
     if (ins & 0x7) == 0:
         return ""
     if (ins & 0x7) == 0x7:
-        return "; j"
+        return "j"
 
     jl = (ins & (1 << 2)) != 0
     je = (ins & (1 << 1)) != 0
@@ -15,23 +15,23 @@ def decode_jump(ins: int) -> str:
 
     # implied: and not jg
     if jl and je:
-        return "; jle"
+        return "jle"
     # implied: and not je
     if jl and jg:
-        return "; jne"
+        return "jne"
     # implied: and not je
     if je and jg:
-        return "; jge"
+        return "jge"
 
     # implied: only one flag is 1
     if jl:
-        return "; jl"
+        return "jl"
     if je:
-        return "; je"
+        return "je"
     if jg:
-        return "; jg"
+        return "jg"
 
-    return "; <unknown>"
+    return "<unknown>"
 
 
 # return op, and whether it's a one-op or two-op
@@ -90,30 +90,41 @@ def decode_dest(ins: int) -> str:
     dA = (ins & (1 << 5)) != 0
     dD = (ins & (1 << 4)) != 0
     dM = (ins & (1 << 3)) != 0
-    dest_s = ""
+    dest = ""
     if dA:
-        dest_s += "A "
+        dest += "A "
     if dD:
-        dest_s += "D "
+        dest += "D "
     if dM:
-        dest_s += "M"
-    if dest_s:
-        dest_s += ", "
-    return dest_s
+        dest += "M"
 
+    return dest
 
-def decode(ins: int) -> str:
+
+def decode_instruction_complete(ins: int) -> list[str]:
+    """
+    Will return a 5 element list/tuple/whatever
+    mnemonic, destination, X, Y, jumpdest
+    """
     if ins & 0x8000 == 0:
         # mov? ldr? ldi? aaaaaaaaaaa....
-        return f"mov  A, #{ins}"
+        return ["mov", "A", f"#{ins}", "", ""]
     else:
-        dest_s = decode_dest(ins)
         codename, two_op = decode_ins(ins)
+        dest = decode_dest(ins)
         op1 = decode_arg1(ins)
-        op2 = decode_arg2(ins)
+        op2 = decode_arg2(ins) if two_op else ""
+        jumpdest = decode_jump(ins)
+        return [codename, dest, op1, op2, jumpdest]
+
+
+def print_decoded(ins: int) -> str:
+    (codename, dest, op1, op2, jumpdest) = decode_instruction_complete(ins)
 
-        op2_s = f", {op2}" if two_op else ""
-        return f"{codename:<5}{dest_s:<8}{op1:<3}{op2_s:<5}{decode_jump(ins)}"
+    dest_str = f"{dest:<5}, " if dest else 7 * " "
+    jumpdest_str = f"; {jumpdest}" if jumpdest else ""
+    op2_str = f", {op2}" if op2 else ""
+    return f"{codename:<5}{dest_str}{op1:<2}{op2_str:<5}{jumpdest_str}"
 
 
 def main():
@@ -129,7 +140,7 @@ def main():
                 if not insb:
                     break
                 ins = int.from_bytes(insb)
-                print(f"\t{insb[0]:02x} {insb[1]:02x}\t{decode(ins)}")
+                print(f"\t{insb[0]:02x} {insb[1]:02x}\t{print_decoded(ins)}")
 
     except FileNotFoundError:
         print(f"File {filename} not found.")
-- 
cgit v1.2.3