Nayuta Eboot Insert v1

# Insert Nayuta eboot.
# Need decrypted eboot in file boot.orig and ebootdump.csv w/ text to insert
# ebootdump.csv: must be in tab-separated format. Cols beyond the 2nd are ignored
# ebootdump.csv: must be saved with SHIFT-JIS encoding

import os

def get_data(filename):
    totalbytes = os.path.getsize(filename)
    infile = open(filename, 'rb')
    totalfiledata = infile.read(totalbytes)
    return totalfiledata

def replacestr(origstr,replacestr,startpos,replacelen):
#Returns a string with a replaced sub-string
#origstr - the original string, replacestr = the string to replace
#startpos - where the replacement string should go
#replacelen - how many characters of the original string to replace
    return origstr[:startpos] + replacestr + origstr[startpos+replacelen:]

def text_decode(text):
    while '{ ' in text:
        startpos = text.find('{ ')
        endpos = text.find(' }')
        s = text[startpos+1:endpos]
        s = s.translate(None,' ')
        s = s.decode('hex')
        text = text[:startpos] + s + text[endpos+2:]
    return text

inputdata = []
with open('ebootdump.csv','rb') as f:
    for line in f:
        line = line.translate(None,"\r\n") #Trims newline characters
        line = line.split('\t')
        addr = int(line[0],16)
        inputdata.append((addr,line[1]))

filedata = get_data('boot.orig')

for addr, text in inputdata:
    pos = filedata.find('\x00',addr)
    while filedata[pos] == '\x00':
        pos += 1
    avail_len = pos - addr - 1
    text = text_decode(text)
    if len(text) > avail_len:
        print "Text %s at address %s len is %d; max len is %d" \
              % (text, hex(addr), len(text), avail_len)
        text = text[:avail_len]
    text = text + (avail_len - len(text))*'\x00'
    filedata = replacestr(filedata,text,addr,avail_len)

outfile = open('EBOOT.BIN','wb')
outfile.write(filedata)
outfile.close()