Converting code in IDA with a simple script

The below code is a very efficient and simple way of converting chunks of Bytes to code. This becomes specially handy when analyzing large binaries, specially firmware.

The script first asks for the start and end addresses (these are both auto-filled based on the selected address on the disassembly vie and the last address of the code segment).

The it automagically starts creating functions and if there are locations where it can’t, it will display the address in the console so by double-clicking it you can go to that address and analyze whether it’s a function or maybe it’s a bunch of data that needs to be manually analyzed.

import ida_kernwin
import idautils
import idaapi
import idc


def make_functions_in_range(start_ea, end_ea):
    ea = start_ea
    failed_addrs = []

    while ea < end_ea:
        if idc.is_unknown(idc.get_full_flags(ea)):
            func_start = ea
            

            res = idc.add_func(func_start)
            print("res", res)

            if not res or idc.get_func_name(func_start) == '':
                failed_addrs.append(func_start)

            ea = idc.next_head(func_start, end_ea)

        else:
            ea += 1

    if failed_addrs:
        print("Could not create function at:")
        for a in failed_addrs:
            tmp = idc.get_wide_word(a)
            # Skip some bytes which are not functions.
            if tmp != 0xBF00:
                print("  - {0:X}".format(a))

    return failed_addrs


def main():
    start = ida_kernwin.ask_addr(get_screen_ea(), "Start address:")
    if start is None:
        return

    end = ida_kernwin.ask_addr(idc.get_segm_end(start), "End address:")
    if end is None:
        return

    failed = make_functions_in_range(start, end)

if __name__ == "__main__":
    main()