import idc

from idautils import *

BOOT_SEGMENT = "QCOM_BOOT"

class SBL_HEADER:

    def __init__(self, data):

        self.load_index = int.from_bytes(data[0:4], 'little')

        self.flash_partition_version = int.from_bytes(data[4:8], 'little')

        self.image_source_pointer = int.from_bytes(data[8:12], 'little')

        self.image_dest_pointer = int.from_bytes(data[12:16], 'little')

        self.image_size = int.from_bytes(data[16:20], 'little')

        self.code_size = int.from_bytes(data[20:24], 'little')

        self.signature_addr = int.from_bytes(data[24:28], 'little')

        self.signature_size = int.from_bytes(data[28:32], 'little')

        self.cert_chain_addr = int.from_bytes(data[32:36], 'little')

        self.cert_chain_size = int.from_bytes(data[36:40], 'little')

def load_file_data(li):

    size = idaapi.get_fileregion_offset(li)

    data = idaapi.get_bytes(li, size)

    return data

def accept_file(li, n):

    if n > 0:

        return 0

    data = load_file_data(li)

    if not data or len(data) < 0x100:

        return 0

    header = SBL_HEADER(data)

    idaapi.set_processor_type("ARM", idaapi.SETPROC_ALL)

    return "Qualcomm MBN Bootchain Stage"

def load_file(li, neflags, formatname):

    data = load_file_data(li)

    if not data or len(data) < 0x100:

        idaapi.loader_failure("cannot read input file\n")

    header = SBL_HEADER(data)

    idaapi.file2base(li, len(data), header.image_dest_pointer, header.image_dest_pointer + header.code_size, True)

    if not idaapi.add_segm(0, header.image_dest_pointer, header.image_dest_pointer + header.code_size, BOOT_SEGMENT, "CODE"):

        idaapi.loader_failure("cannot create code segment\n")

    seg = idaapi.get_segm_by_name(BOOT_SEGMENT)

    idaapi.set_segm_addressing(seg, 1)

    idaapi.add_entry(header.image_dest_pointer, header.image_dest_pointer, "boot_base", True)

def save_file(li, file, formatname):

    seg = idaapi.get_segm_by_name(BOOT_SEGMENT)

    if not seg:

        return 0

    idaapi.base2file(file, 0, seg.start_ea, seg.end_ea)

    return 1

def PLUGIN_ENTRY():

    return idaapi.plugin_t(

        flags=idaapi.PLUGIN_UNL,

        comment="Qualcomm MBN Bootchain Stage Loader",

        help="Loads Qualcomm MBN Bootchain Stage files",

        wanted_name="QCOM MBN Loader",

        wanted_hotkey="",

        init=lambda: idaapi.PLUGIN_OK,

        term=lambda: None,

        run=lambda arg: None

    )