tbxi/tbxi/powerpc_build.py

265 lines
8.7 KiB
Python

from os import path
import shlex
import ast
import re
import struct
from .lowlevel import ConfigInfo
from . import dispatcher
MAPNAMES = ['sup', 'usr', 'cpu', 'ovl']
BATNAMES = ['ibat0', 'ibat1', 'ibat2', 'ibat3', 'dbat0', 'dbat1', 'dbat2', 'dbat3']
class CodeLine(dict):
def __getattr__(self, attrname):
return self[attrname]
def __setattr__(self, attrname, attrval):
self[attrname] = attrval
def iter_configinfo_names():
n = 1
while True:
yield 'Configfile-%d' % n
n += 1
def is_safe(expr):
chexpr = re.sub(r'\b(0x[0-9a-f]+|0b[01]+|\b[1-9][0-9]*|\b0\b)', '', expr.lower())
for char in chexpr:
if char not in '+-|&()':
return False
return True
def sub_constants(expr):
K = dict(PMDT_InvalidAddress=0xA00, PMDT_Available=0xA01)
for k, v in K.items():
expr = re.sub(r'\b%s\b' % k, '(%s)' % hex(v), expr)
return expr
def parse_configinfo(src_path):
filenames = {}
linelist = []
chunks = {'': linelist} # must sort as first
for line in open(src_path):
words = shlex.split(line, comments=True, posix=True)
if len(words) == 0: continue
if len(words) == 1 and words[0].startswith('[') and words[0].endswith(']'):
linelist = []
chunks[words[0][1:-1]] = linelist
continue
worddict = CodeLine()
linelist.append(worddict)
for word in words:
k, sep, v = word.partition('=')
if sep:
v1, sep, v2 = v.partition('=') # the second = delimits a filename
if sep and k.endswith('Offset'):
worddict[k] = v1
filenames[k] = v2
else:
worddict[k] = v
# do some cleanup: replace all instances of BASE with ROMImageBaseOffset
base = '-0x30C000' # bad fallback, don't skip ROMImageBaseOffset
lines = chunks['']
for words in lines:
for k, v in words.items():
if k == 'ROMImageBaseOffset':
base = v
base = '(%s)' % base
for header, lines in chunks.items():
for words in lines:
for k, v in list(words.items()):
if k == 'BootstrapVersion':
words[k] = v.encode('mac_roman')
continue
if k == 'brpn':
v2 = re.sub(r'\bBASE\b', base, v)
is_relative = (v != v2)
if is_safe(v2):
words[k] = is_relative, eval(v2)
continue
v2 = re.sub(r'\bBASE\b', base, v)
v2 = sub_constants(v2)
if is_safe(v2):
words[k] = eval(v2)
return chunks, filenames
def insert_and_assert(binary, insertee, offset):
new_len = offset + len(insertee)
binary.extend(b'\0' * (new_len - len(binary)))
existing = binary[offset:offset+len(insertee)]
if any(existing): # premature optimisation
for a, b in zip(insertee, existing):
if a != 0 and b != 0 and a != b:
raise ValueError('inserting over something else @%X' % offset)
binary[offset:offset+len(insertee)] = insertee
def checksum_image(binary, ofs):
# ugly, but iterating the right was is painfully slow
byte_lanes = [sum(binary[i::8]) for i in range(8)]
zeroed_byte_lanes = list(byte_lanes)
for j in range(ofs, ofs+40):
zeroed_byte_lanes[j % 8] -= binary[j]
sum32 = [lane % (1<<32) for lane in zeroed_byte_lanes]
sum64 = sum(lane << (k * 8) for (k, lane) in enumerate(reversed(zeroed_byte_lanes)))
sum64 %= 1 << 64
allsums = b''.join(x.to_bytes(4, byteorder='big') for x in sum32)
allsums += sum64.to_bytes(8, byteorder='big')
return allsums
def build(src):
cilist = []
for ciname in iter_configinfo_names():
try:
cilist.append(parse_configinfo(path.join(src, ciname)))
except (FileNotFoundError, NotADirectoryError):
break
if len(cilist) == 0: raise dispatcher.WrongFormat
# Expand this as we go
rom = bytearray()
# Now we go through every configinfo and insert it (oh hell)
for ci, filenames in reversed(cilist):
fields = {key: 0 for key in ConfigInfo._fields}
lowmem = bytearray()
pagemap = bytearray()
segptrs = [bytearray(128) for _ in MAPNAMES]
batmap = bytearray() # will be padded to 128
batptrs = [0 for _ in MAPNAMES]
for header, lines in ci.items():
if header == '':
for words in lines:
for k, v in words.items():
if k in fields:
fields[k] = v
# The parallel filenames dict tells us what data to put at that address
if k in filenames:
blob = dispatcher.build(path.join(src, filenames[k]))
try:
insert_and_assert(rom, blob, v - fields['ROMImageBaseOffset'])
except ValueError:
raise ValueError('Could not insert %r at %s' % (filenames[k], v - fields['ROMImageBaseOffset']))
elif header == 'LowMemory':
for words in lines:
lowmem.extend(struct.pack('>LL', words.address, words.value))
elif header == 'PageMappingInfo':
for words in lines:
if 'segment_ptr_here' in words:
mapidx = MAPNAMES.index(words.map.lower())
struct.pack_into('>LL', segptrs[mapidx], 8 * words.segment_ptr_here, len(pagemap), words.segment_register)
elif 'special_pmdt' in words:
key = 'PageMap%sOffset' % words.special_pmdt.upper()
fields[key] = len(pagemap)
elif 'pmdt_page_offset' in words:
long2 = words.phys_page << 12 | words.attr
pagemap.extend(struct.pack('>HHL', words.pmdt_page_offset, words.pages_minus_1, long2))
elif header == 'BatMappingInfo':
for words in lines:
if 'bat_ptr_here' in words:
batidx = BATNAMES.index(words.bat_ptr_here.lower())
mapidx = MAPNAMES.index(words.map.lower())
fourbits = len(batmap) // 8
shift = 4 * (7 - batidx)
batptrs[mapidx] |= fourbits << shift
elif 'bepi' in words:
ubat = lbat = 0
ubat |= words.bepi & 0xFFFE0000 # trailing zeroes hopefully
ubat |= words.bl_128k << 2
ubat |= words.vs << 1
ubat |= words.vp
lbat |= words.unk23 << 8
lbat |= words.wim << 4
lbat |= words.ks << 3
lbat |= words.ku << 2
lbat |= words.pp
is_relative, brpn = words.brpn # special case in parse_configinfo
if is_relative: lbat |= 0x200
lbat = (lbat + brpn) & 0xFFFFFFFF
batmap.extend(struct.pack('>LL', ubat, lbat))
# Get the awkward array data into the struct
fields['SegMap32SupInit'] = segptrs[0]
fields['SegMap32UsrInit'] = segptrs[1]
fields['SegMap32CPUInit'] = segptrs[2]
fields['SegMap32OvlInit'] = segptrs[3]
fields['BatMap32SupInit'] = batptrs[0]
fields['BatMap32UsrInit'] = batptrs[1]
fields['BatMap32CPUInit'] = batptrs[2]
fields['BatMap32OvlInit'] = batptrs[3]
fields['BATRangeInit'] = batmap
# Great, now we'll neaten up fields and blat it out
lowmem.extend(b'\0\0\0\0')
flat = bytearray(0x1000)
ptr = len(flat)
ptr -= len(lowmem)
insert_and_assert(flat, lowmem, ptr)
fields['MacLowMemInitOffset'] = ptr
if len(pagemap) > 0:
ptr -= len(pagemap)
insert_and_assert(flat, pagemap, ptr)
fields['PageMapInitOffset'] = ptr
fields['PageMapInitSize'] = len(pagemap)
insert_and_assert(flat, ConfigInfo.pack(**fields), 0)
# Insert the ConfigInfo struct!
configinfo_offset = -fields['ROMImageBaseOffset'] # this var used below
insert_and_assert(rom, flat, configinfo_offset)
rom.extend(b'\0' * (fields['ROMImageSize'] - len(rom)))
# let's do a cheeky checksum!
cksum = checksum_image(rom, configinfo_offset)
insert_and_assert(rom, cksum, configinfo_offset) # overwrites start of ConfigInfo
return bytes(rom)