bootimg.py

#!/usr/bin/env python

import argparse
import sys
import subprocess
from shutil import copy, rmtree
from os import listdir, makedirs, chdir, getcwd, walk
from os.path import isdir, isfile, join, exists, abspath, dirname

prebuilts_dir='prebuilts'

def unpack_boot(bootimg, base_dir, tmp_dir):

    mkboot = join(join(base_dir, prebuilts_dir), 'mkboot')
    p = subprocess.Popen([mkboot, bootimg, tmp_dir])
    p.communicate()
    return map(lambda x:join(tmp_dir, x), [name for name in listdir(tmp_dir)
            if isdir(join(tmp_dir, name))])[0]

def repack_boot(base_dir, tmp_dir, out):
    mkboot = join(join(base_dir, prebuilts_dir), 'mkboot')
    p = subprocess.Popen([mkboot, tmp_dir, join(out, 'newboot.img')])
    p.communicate()

def unpack_repack(bootimg, base_dir, tmp_dir, out, sepolicy, file_contexts, seapp_contexts, property_contexts):

    ramdisk_dir = unpack_boot(bootimg, base_dir, tmp_dir)
    
    if sepolicy and isfile(sepolicy):
        print 'Copying sepolicy'
        copy(sepolicy, ramdisk_dir)

    if file_contexts and isfile(file_contexts):
        print 'Copying file_contexts'
        copy(file_contexts, ramdisk_dir)

    if seapp_contexts and isfile(seapp_contexts):
        print 'Copying seapp_contexts file'
        copy(seapp_contexts, ramdisk_dir)

    if property_contexts and isfile(property_contexts):
        print 'Copying property_contexts file'
        copy(property_contexts, ramdisk_dir)
        
    repack_boot(base_dir, tmp_dir, out)


def update_boot(args):

    project_dir = dirname(abspath(__file__))
    tmp_dir = join(project_dir, 'tmp')

    if exists(tmp_dir):
        rmtree(tmp_dir)

    if exists(args.out_dir):
        rmtree(args.out_dir)
    
    makedirs(args.out_dir)

    if not isfile(args.bootimg):
        print 'Please specify a valid boot.img file'
        raise SystemExit

    unpack_repack(args.bootimg, project_dir, tmp_dir, args.out_dir, args.sepolicy,
                  args.file_contexts, args.seapp_contexts, args.property_contexts)
    rmtree(tmp_dir)

def main():
    parser = argparse.ArgumentParser(description=__doc__)

    parser = argparse.ArgumentParser(description='Unpack and repack boot.img')
    parser.add_argument('-boot', required=True, dest='bootimg', help='boot.img file')
    parser.add_argument('-sepolicy', required=False, dest='sepolicy', 
                        help='new sepolicy file to add in the boot.img')
    parser.add_argument('-file_contexts', required=False, dest='file_contexts', 
                        help='new file_contexts file to add in the boot.img')
    parser.add_argument('-seapp_contexts', required=False, dest='seapp_contexts', 
                        help='new seapp_contexts file to add in the boot.img')
    parser.add_argument('-property_contexts', required=False, dest='property_contexts', 
                        help='new property_contexts file to add in the boot.img')
    parser.add_argument('-out', required=True, dest='out_dir', help='output directory')
    parser.set_defaults(func=update_boot)
    args = parser.parse_args()
    args.func(args)

if __name__ == '__main__':
    main()