esptool.py 文件源码

def _read_sections(self, f, section_header_offs, shstrndx):
        f.seek(section_header_offs)
        section_header = f.read()
        LEN_SEC_HEADER = 0x28
        if len(section_header) == 0:
            raise FatalError("No section header found at offset %04x in ELF file." % section_header_offs)
        if len(section_header) % LEN_SEC_HEADER != 0:
            print('WARNING: Unexpected ELF section header length %04x is not mod-%02x' % (len(section_header),LEN_SEC_HEADER))

        # walk through the section header and extract all sections
        section_header_offsets = range(0, len(section_header), LEN_SEC_HEADER)

        def read_section_header(offs):
            name_offs,sec_type,_flags,lma,sec_offs,size = struct.unpack_from("<LLLLLL", section_header[offs:])
            return (name_offs, sec_type, lma, size, sec_offs)
        all_sections = [read_section_header(offs) for offs in section_header_offsets]
        prog_sections = [s for s in all_sections if s[1] == ELFFile.SEC_TYPE_PROGBITS]

        # search for the string table section
        if not shstrndx * LEN_SEC_HEADER in section_header_offsets:
            raise FatalError("ELF file has no STRTAB section at shstrndx %d" % shstrndx)
        _,sec_type,_,sec_size,sec_offs = read_section_header(shstrndx * LEN_SEC_HEADER)
        if sec_type != ELFFile.SEC_TYPE_STRTAB:
            print('WARNING: ELF file has incorrect STRTAB section type 0x%02x' % sec_type)
        f.seek(sec_offs)
        string_table = f.read(sec_size)

        # build the real list of ELFSections by reading the actual section names from the
        # string table section, and actual data for each section from the ELF file itself
        def lookup_string(offs):
            raw = string_table[offs:]
            return raw[:raw.index(b'\x00')]

        def read_data(offs,size):
            f.seek(offs)
            return f.read(size)

        prog_sections = [ELFSection(lookup_string(n_offs), lma, read_data(offs, size)) for (n_offs, _type, lma, size, offs) in prog_sections
                         if lma != 0]
        self.sections = prog_sections