Flattener: 32-bit

This commit is contained in:
Elliot Nunn 2022-03-31 11:00:01 +08:00
parent e568ef33af
commit f67194a889

View File

@ -34,14 +34,6 @@ if not resources or resources[0].id != 0:
jt_resource, *other_resources = resources
bigboy = bytearray()
for r in other_resources:
bigboy.extend(bytes(addr(r.id) - len(bigboy)))
bigboy.extend(r)
with open(args.dest, "wb") as f:
f.write(bigboy)
jump_table = {} # a5_ofs: (segnum, seg_ofs)
(jt_size, a5_offset_of_jt) = struct.unpack_from(">LL", jt_resource, 8)
@ -125,6 +117,25 @@ def is_mxbg_str(s):
return True
def unpack_relocs(blob):
# blob = memoryview(blob)
while True:
if blob[:2] == b"\x00\x00":
break
elif blob[0] == 0 and blob[1] & 0x80:
yield ((blob[1] << 25) + (blob[2] << 17) + (blob[3] << 9) + (blob[4] << 1)) & 0xFFFFFFFF
blob = blob[5:]
elif blob[0] & 0x80:
yield ((blob[0] << 9) + (blob[1] << 1)) & 0xFFFF
blob = blob[2:]
else:
yield blob[0] << 1
blob = blob[1:]
with open(args.dest + ".py", "w") as idascript:
# Find MacsBug symbols
namedict = {}
@ -146,11 +157,37 @@ with open(args.dest + ".py", "w") as idascript:
interseg_calls = {}
for r in other_resources:
for i in range(0, len(r) - 3, 2):
if r[i : i + 2] in (b"\x4e\xad", b"\x48\x6d") or (r[i] == 0x41 and r[i + 1] & 0xF8 == 0xE8):
(targ,) = struct.unpack_from(">h", r, i + 2)
if targ > 0:
interseg_calls.setdefault(targ, []).append(addr(r.id) + i)
# 32-bit segment
if r[:2] == b"\xFF\xFF":
a5relocs, pcrelocs = struct.unpack_from(">LxxxxL", r, 0x14)
ofs = 0
for reloc in unpack_relocs(r[a5relocs:]):
ofs = (ofs + reloc) & 0xFFFFFFFF # reloc can be negative!
(a5offset,) = struct.unpack_from(">L", r, ofs)
# Instead of hacking IDA to treat xxxx(A5) as a function address,
# just stuff the actual function address in the JMP target
if a5offset in jump_table:
target_seg, target_seg_offset = jump_table[a5offset]
target_addr = addr(target_seg) + target_seg_offset
struct.pack_into(">L", r, ofs, target_addr)
ofs = 0
for reloc in unpack_relocs(r[pcrelocs:]):
ofs = (ofs + reloc) & 0xFFFFFFFF # reloc can be negative!
(target_addr,) = struct.unpack_from(">L", r, ofs)
target_addr += addr(r.id)
struct.pack_into(">L", r, ofs, target_addr)
# 16-bit segment
else:
for i in range(0, len(r) - 3, 2):
if r[i : i + 2] in (b"\x4e\xad", b"\x48\x6d") or (r[i] == 0x41 and r[i + 1] & 0xF8 == 0xE8):
(targ,) = struct.unpack_from(">h", r, i + 2)
if targ > 0:
interseg_calls.setdefault(targ, []).append(addr(r.id) + i)
# Make some neat names for the segments...
segnames = {}
@ -178,3 +215,11 @@ with open(args.dest + ".py", "w") as idascript:
for bigboy_ofs, name in sorted(namedict.items()):
cool_name = f"{segnames[bigboy_ofs >> 20]}${name}"
print(f'MakeFunction(0x{bigboy_ofs:X}); MakeName(0x{bigboy_ofs:X}, "{cool_name}")', file=idascript)
bigboy = bytearray()
for r in other_resources:
bigboy.extend(bytes(addr(r.id) - len(bigboy)))
bigboy.extend(r)
with open(args.dest, "wb") as f:
f.write(bigboy)