tx_decompress_v3_internal.py

# The following is adapted from https://github.com/reswitched/loaders/blob/master/nxo64.py
#
# ===========================================================================================
#
# Copyright 2017 Reswitched Team
#
# Permission to use, copy, modify, and/or distribute this software for any purpose with or
# without fee is hereby granted, provided that the above copyright notice and this permission
# notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
# SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
# THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
# OR PERFORMANCE OF THIS SOFTWARE.

import os
import struct
import lz4.block

uncompress = lz4.block.decompress

# Skip the non-standard size field
kip_skip = 0
 
def kip1_blz_decompress(compressed):
    compressed_size, init_index, uncompressed_addl_size = struct.unpack('<III', compressed[-0xC:])
    decompressed = compressed[:] + '\x00' * uncompressed_addl_size
    decompressed_size = len(decompressed)
    if len(compressed) != compressed_size:
        assert len(compressed) > compressed_size
        compressed = compressed[len(compressed) - compressed_size:]
    if not (compressed_size + uncompressed_addl_size):
        return ''
    compressed = map(ord, compressed)
    decompressed = map(ord, decompressed)
    index = compressed_size - init_index
    outindex = decompressed_size
    while outindex > 0:
        index -= 1
        control = compressed[index]
        for i in xrange(8):
            if control & 0x80:
                if index < 2:
                    print(ValueError('INFO: Compression out of bounds!'))
                index -= 2
                segmentoffset = compressed[index] | (compressed[index+1] << 8)
                segmentsize = ((segmentoffset >> 12) & 0xF) + 3
                segmentoffset &= 0x0FFF
                segmentoffset += 2
                if outindex < segmentsize:
                    print(ValueError('INFO: Compression out of bounds!'))
                for j in xrange(segmentsize):
                    if outindex + segmentoffset >= decompressed_size:
                        print(ValueError('INFO: Compression out of bounds!'))
                    data = decompressed[outindex+segmentoffset]
                    outindex -= 1
                    decompressed[outindex] = data
            else:
                if outindex < 1:
                    print(ValueError('INFO: Compression out of bounds!'))
                outindex -= 1
                index -= 1
                decompressed[outindex] = compressed[index]
            control <<= 1
            control &= 0xFF
            if not outindex:
                break
    return ''.join(map(chr, decompressed))
    
class BinFile(object):
    def __init__(self, li):
        self._f = li
 
    def read(self, arg):
        if isinstance(arg, str):
            fmt = '<' + arg
            size = struct.calcsize(fmt)
            raw = self._f.read(size)
            out = struct.unpack(fmt, raw)
            if len(out) == 1:
                return out[0]
            return out
        elif arg is None:
            return self._f.read()
        else:
            out = self._f.read(arg)
            return out
 
    def read_from(self, arg, offset):
        old = self.tell()
        try:
            self.seek(offset)
            out = self.read(arg)
        finally:
            self.seek(old)
        return out
 
    def seek(self, off):
        self._f.seek(off)
 
    def close(self):
        self._f.close()
 
    def tell(self):
        return self._f.tell()
        
def decompress_kip(fileobj):
    f = BinFile(fileobj)

    if f.read_from('4s', 0 + kip_skip) != 'KIP1':
        raise NxoException('Invalid KIP magic')
 
    tloc, tsize, tfilesize = f.read_from('III', 0x20 + kip_skip)
    rloc, rsize, rfilesize = f.read_from('III', 0x30 + kip_skip)
    dloc, dsize, dfilesize = f.read_from('III', 0x40 + kip_skip)
     
    toff = 0x100
    roff = toff + tfilesize
    doff = roff + rfilesize

    bsssize = f.read_from('I', 0x18 + kip_skip)
 
    text = kip1_blz_decompress(str(f.read_from(tfilesize, toff + kip_skip)))
    ro   = kip1_blz_decompress(str(f.read_from(rfilesize, roff + kip_skip)))
    data = kip1_blz_decompress(str(f.read_from(dfilesize, doff + kip_skip)))

    full = text
    if rloc >= len(full):
        full += '\0' * (rloc - len(full))
    else:
        full = full[:rloc]
    full += ro
    if dloc >= len(full):
        full += '\0' * (dloc - len(full))
    else:
        full = full[:dloc]
    full += data
 
    return full
    
def decompress_nso(fileobj):
    f = BinFile(fileobj)

    if f.read_from('4s', 0) != 'NSO0':
        raise NxoException('Invalid NSO magic')

    toff, tloc, tsize = f.read_from('III', 0x10)
    roff, rloc, rsize = f.read_from('III', 0x20)
    doff, dloc, dsize = f.read_from('III', 0x30)

    tfilesize, rfilesize, dfilesize = f.read_from('III', 0x60)
    bsssize = f.read_from('I', 0x3C)

    text = uncompress(f.read_from(tfilesize, toff), uncompressed_size=tsize)
    ro   = uncompress(f.read_from(rfilesize, roff), uncompressed_size=rsize)
    data = uncompress(f.read_from(dfilesize, doff), uncompressed_size=dsize)

    full = text
    if rloc >= len(full):
        full += '\0' * (rloc - len(full))
    else:
        full = full[:rloc]
    full += ro
    if dloc >= len(full):
        full += '\0' * (dloc - len(full))
    else:
        full = full[:dloc]
    full += data
 
    return full

# ===========================================================================================

def get_ver_int(boot_ver):
    if (boot_ver[1] == 0x30) and (boot_ver[0] == 0x2E302E33):       # TX BOOT 3.0.0
        return 300
    else:
        return 0

f = open("boot.dat", "rb")
b = f.read()
f.close()

# Get the version from boot.dat
version = get_ver_int(struct.unpack("II", b[0x08:0x10]))

if version >= 300:
    kip_skip = 0x100
    hbl_nso_off = 0
    hbl_nso_size = 0
    tx_nso_off = 0
    tx_nso_size = 0
else:
    exit()

# Check which firmware files are present
kip_list = os.listdir("./sxos/firmware/")

# No files found
if not kip_list:
    exit()

os.chdir("./sxos/firmware/")
    
for i in xrange(len(kip_list)):
    if os.path.isfile(kip_list[i]):
        kip_file = open(kip_list[i], "rb")    
        kip_file.seek(kip_skip)
        kip_magic = struct.unpack("I", kip_file.read(4))[0]
        
        # Make sure the file is a KIP1
        if kip_magic == 0x3150494B:
            kip_name = kip_file.read(12).rstrip('\x00')
            
            # Create folder for this KIP1
            if not os.path.exists("./{:s}/".format(kip_name)):
                os.mkdir("./{:s}/".format(kip_name))
            os.chdir("./{:s}/".format(kip_name))  
            
            # Decompress
            dec_kip_file = open("{:s}.bin".format(kip_name), "wb")
            dec_kip_file.write(decompress_kip(kip_file))
            dec_kip_file.close()
            
            # Handle Loader's NSOs
            if (kip_name == "Loader") and \
                    ((hbl_nso_off > 0) and (hbl_nso_off > 0)) and \
                    ((tx_nso_off > 0) and (tx_nso_size > 0)):
                # Create folder for the NSOs
                if not os.path.exists("./NSO/"):
                    os.mkdir("./NSO/")
                
                # Extract the NSOs
                dec_kip_file = open("{:s}.bin".format(kip_name), "rb")
                dec_kip_file.seek(tx_nso_off)
                tx_nso_data = dec_kip_file.read(tx_nso_size)
                dec_kip_file.seek(hbl_nso_off)
                hbl_nso_data = dec_kip_file.read(hbl_nso_size)
                dec_kip_file.close()
                
                # Save the compressed NSOs
                tx_nso_file = open("./NSO/tx.bin", "wb")
                hbl_nso_file = open("./NSO/hbl.bin", "wb")
                tx_nso_file.write(tx_nso_data)
                hbl_nso_file.write(hbl_nso_data)
                hbl_nso_file.close()
                tx_nso_file.close()
                
                os.chdir("./NSO/")
                
                # Create folders
                if not os.path.exists("./tx/".format(kip_name)):
                    os.mkdir("./tx/".format(kip_name)) 
                if not os.path.exists("./hbl/".format(kip_name)):
                    os.mkdir("./hbl/".format(kip_name)) 
                
                # Decompress
                tx_nso_file = open("tx.bin", "rb")
                hbl_nso_file = open("hbl.bin", "rb")
                dec_tx_nso_file = open("./tx/main", "wb")
                dec_hbl_nso_file = open("./hbl/main", "wb")
                dec_tx_nso_file.write(decompress_nso(tx_nso_file))
                dec_hbl_nso_file.write(decompress_nso(hbl_nso_file))
                dec_hbl_nso_file.close()
                dec_tx_nso_file.close()
                hbl_nso_file.close()
                tx_nso_file.close()
                
                os.chdir("..")
            os.chdir("..") 
            
        kip_file.close()