tbxi/tbxi/supermario_build.py
Elliot Nunn 93c5d270cd Support fixed-offset resources
Most TNT-era ROMs use this feature of RomLayout. Heuristically detect,
report and rebuild these ROMs.
2019-06-11 12:29:47 +08:00

157 lines
4.4 KiB
Python

import shlex
import ast
import struct
from os import path
from . import lowlevel
from . import dispatcher
ALIGN = 16
REV_COMBO_FIELDS = {v: k for (k, v) in lowlevel.COMBO_FIELDS.items()}
def checksum(binary):
binary[:4] = bytes(4)
binary[0x30:0x40] = bytes(16)
lanes = [sum(binary[i::4]) & 0xFFFFFFFF for i in range(4)]
struct.pack_into('>LLLL', binary, 0x30, *lanes)
oneword = (sum(binary[::2])*256 + sum(binary[1::2])) & 0xFFFFFFFF
struct.pack_into('>L', binary, 0, oneword)
def build(src):
if not path.exists(path.join(src, 'Romfile')): raise dispatcher.WrongFormat
romfile = dispatcher.build(path.join(src, 'Romfile')).decode('utf8').split('\n')
rsrc_list = []
for l in romfile:
words = shlex.split(l, comments=True, posix=True)
thisdict = {}
for word in words:
a, sep, b = word.partition('=')
if sep == '=':
if a == 'type':
b = b.encode('mac_roman')
elif a in ('id', 'rom_size', 'offset'):
b = ast.literal_eval(b)
thisdict[a] = b
if 'rom_size' in thisdict:
rom_size = thisdict['rom_size']
elif 'type' in thisdict:
rsrc_list.append(thisdict)
rom = bytearray(b'kc' * (rom_size // 2))
free_map = bytearray(b'X' * (rom_size // ALIGN))
def rom_insert(offset, binary, letter=' '):
letter = letter.encode('ascii')
if offset + len(binary) > len(rom):
raise IndexError('ROM too small to insert %r at %s' % (letter, hex(offset)))
rom[offset:offset+len(binary)] = binary
# Populate the informational array of letters
# Only capitals can be overwritten
start = offset // ALIGN
stop = (offset + len(binary) - 1) // ALIGN + 1
for i in range(start, stop):
if free_map[i] != 20:
if free_map[i:i+1].upper() != free_map[i:i+1]:
raise ValueError('Tried to insert %r over %r at %s' % (letter, free_map[i], hex(offset)))
free_map[i:i+1] = letter
def find_free(length):
length = (length + ALIGN - 1) // ALIGN
return free_map.index(b'X' * length) * ALIGN
maincode = dispatcher.build(path.join(src, 'MainCode'))
rom_insert(0, maincode, 'm')
head_ptr = find_free(16)
rom_insert(head_ptr, b'fake header', 'H')
try:
decldata = dispatcher.build(path.join(src, 'DeclData'))
except FileNotFoundError:
pass
else:
rom_insert(len(rom) - len(decldata), decldata, 'd')
# now blat in the resources
ent_ptr = 0
bogus_off = 0x5C
for r in rsrc_list:
data = dispatcher.build(path.join(src, r['src']))
# First place the data, including the fake MemMgr header
if 'offset' in r:
ofs = r['offset']
else:
ofs = find_free(16 + len(data))
mm_ptr = ofs + 4
data_ptr = ofs + 16
# And insert that
mm = lowlevel.FakeMMHeader.pack(
MagicKurt=b'Kurt',
MagicC0A00000=0xC0A00000,
dataSizePlus12=len(data) + 12,
bogusOff=bogus_off,
)
rom_insert(mm_ptr - 4, mm + data, 'r')
# Calculate the independently-placed entry struct
combo = r.get('combo', 'AllCombos')
combo = REV_COMBO_FIELDS.get(combo, None)
if combo is None:
combo = ast.literal_eval(combo) << 56
ent = lowlevel.ResEntry.pack(
combo=combo,
offsetToNext=ent_ptr, # this is the previous one
offsetToData=data_ptr,
rsrcType=r['type'],
rsrcID=r['id'],
rsrcAttr=0x58,
rsrcName=r['name'].encode('mac_roman'),
)
# snip off pascal string padding
ent = ent[:0x18 + ent[0x17]]
# Place the entry struct
ent_ptr = find_free(len(ent))
rom_insert(ent_ptr, ent, 'e')
bogus_off += 8
head = lowlevel.ResHeader.pack(
offsetToFirst=ent_ptr,
maxValidIndex=4,
comboFieldSize=8,
comboVersion=1,
headerSize=12,
)
rom_insert(head_ptr, head, 'h')
# now set the size
fields = lowlevel.SuperMarioHeader.unpack_from(rom)._asdict()
fields['RomRsrc'] = head_ptr
fields['RomSize'] = len(rom)
lowlevel.SuperMarioHeader.pack_into(rom, 0, **fields)
# now set the checksums!
checksum(rom)
return bytes(rom)