Diff: tools/flash_algo.py

Revision:

0:01f31e923fe2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/flash_algo.py	Tue Apr 07 12:55:42 2020 +0200
@@ -0,0 +1,359 @@
+#!/usr/bin/env python
+"""
+ mbed
+ Copyright (c) 2017-2019 ARM Limited
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+"""
+
+from __future__ import print_function
+import os
+import struct
+import binascii
+import argparse
+import logging
+from six.moves import StringIO
+import jinja2
+from collections import namedtuple
+from itertools import count
+
+from elftools.common.py3compat import bytes2str
+from elftools.elf.elffile import ELFFile
+from elftools.elf.sections import SymbolTableSection
+
+logger = logging.getLogger(__name__)
+logger.addHandler(logging.NullHandler())
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Algo Extracter")
+    parser.add_argument("input", help="File to extract flash algo from")
+    parser.add_argument("template", default="py_blob.tmpl",
+                        help="Template to use")
+    parser.add_argument("output", help="Output file")
+    args = parser.parse_args()
+
+    with open(args.input, "rb") as file_handle:
+        data = file_handle.read()
+    algo = PackFlashAlgo(data)
+    algo.process_template(args.template, args.output)
+
+
+class PackFlashAlgo(object):
+    """
+    Class to wrap a flash algo
+
+    This class is intended to provide easy access to the information
+    provided by a flash algorithm, such as symbols and the flash
+    algorithm itself.
+    """
+
+    REQUIRED_SYMBOLS = set([
+        "Init",
+        "UnInit",
+        "EraseSector",
+        "ProgramPage",
+    ])
+
+    EXTRA_SYMBOLS = set([
+        "BlankCheck",
+        "EraseChip",
+        "Verify",
+    ])
+
+    def __init__(self, data):
+        """Construct a PackFlashAlgorithm from an ElfFileSimple"""
+        self.elf = ElfFileSimple(data)
+        self.flash_info = PackFlashInfo(self.elf)
+
+        self.flash_start = self.flash_info.start
+        self.flash_size = self.flash_info.size
+        self.page_size = self.flash_info.page_size
+        self.sector_sizes = self.flash_info.sector_info_list
+
+        symbols = {}
+        symbols.update(_extract_symbols(self.elf, self.REQUIRED_SYMBOLS))
+        symbols.update(_extract_symbols(self.elf, self.EXTRA_SYMBOLS,
+                                        default=0xFFFFFFFF))
+        self.symbols = symbols
+
+        sections_to_find = (
+            ("PrgCode", "SHT_PROGBITS"),
+            ("PrgData", "SHT_PROGBITS"),
+            ("PrgData", "SHT_NOBITS"),
+        )
+
+        ro_rw_zi = _find_sections(self.elf, sections_to_find)
+        ro_rw_zi = _algo_fill_zi_if_missing(ro_rw_zi)
+        error_msg = _algo_check_for_section_problems(ro_rw_zi)
+        if error_msg is not None:
+            raise Exception(error_msg)
+
+        sect_ro, sect_rw, sect_zi = ro_rw_zi
+        self.ro_start = sect_ro["sh_addr"]
+        self.ro_size = sect_ro["sh_size"]
+        self.rw_start = sect_rw["sh_addr"]
+        self.rw_size = sect_rw["sh_size"]
+        self.zi_start = sect_zi["sh_addr"]
+        self.zi_size = sect_zi["sh_size"]
+
+        self.algo_data = _create_algo_bin(ro_rw_zi)
+
+    def format_algo_data(self, spaces, group_size, fmt):
+        """"
+        Return a string representing algo_data suitable for use in a template
+
+        The string is intended for use in a template.
+
+        :param spaces: The number of leading spaces for each line
+        :param group_size: number of elements per line (element type
+            depends of format)
+        :param fmt: - format to create - can be either "hex" or "c"
+        """
+        padding = " " * spaces
+        if fmt == "hex":
+            blob = binascii.b2a_hex(self.algo_data)
+            line_list = []
+            for i in xrange(0, len(blob), group_size):
+                line_list.append('"' + blob[i:i + group_size] + '"')
+            return ("\n" + padding).join(line_list)
+        elif fmt == "c":
+            blob = self.algo_data[:]
+            pad_size = 0 if len(blob) % 4 == 0 else 4 - len(blob) % 4
+            blob = blob + "\x00" * pad_size
+            integer_list = struct.unpack("<" + "L" * (len(blob) / 4), blob)
+            line_list = []
+            for pos in range(0, len(integer_list), group_size):
+                group = ["0x%08x" % value for value in
+                         integer_list[pos:pos + group_size]]
+                line_list.append(", ".join(group))
+            return (",\n" + padding).join(line_list)
+        else:
+            raise Exception("Unsupported format %s" % fmt)
+
+    def process_template(self, template_path, output_path, data_dict=None):
+        """
+        Generate output from the supplied template
+
+        All the public methods and fields of this class can be accessed from
+        the template via "algo".
+
+        :param template_path: Relative or absolute file path to the template
+        :param output_path: Relative or absolute file path to create
+        :param data_dict: Additional data to use when generating
+        """
+        if data_dict is None:
+            data_dict = {}
+        else:
+            assert isinstance(data_dict, dict)
+            data_dict = dict(data_dict)
+        assert "algo" not in data_dict, "algo already set by user data"
+        data_dict["algo"] = self
+
+        with open(template_path) as file_handle:
+            template_text = file_handle.read()
+
+        template = jinja2.Template(template_text)
+        target_text = template.render(data_dict)
+
+        with open(output_path, "wb") as file_handle:
+            file_handle.write(target_text)
+
+
+def _extract_symbols(simple_elf, symbols, default=None):
+    """Fill 'symbols' field with required flash algo symbols"""
+    to_ret = {}
+    for symbol in symbols:
+        if symbol not in simple_elf.symbols:
+            if default is not None:
+                to_ret[symbol] = default
+                continue
+            raise Exception("Missing symbol %s" % symbol)
+        to_ret[symbol] = simple_elf.symbols[symbol].value
+    return to_ret
+
+
+def _find_sections(elf, name_type_pairs):
+    """Return a list of sections the same length and order of the input list"""
+    sections = [None] * len(name_type_pairs)
+    for section in elf.iter_sections():
+        section_name = bytes2str(section.name)
+        section_type = section["sh_type"]
+        for i, name_and_type in enumerate(name_type_pairs):
+            if name_and_type != (section_name, section_type):
+                continue
+            if sections[i] is not None:
+                raise Exception("Elf contains duplicate section %s attr %s" %
+                                (section_name, section_type))
+            sections[i] = section
+    return sections
+
+
+def _algo_fill_zi_if_missing(ro_rw_zi):
+    """Create an empty zi section if it is missing"""
+    s_ro, s_rw, s_zi = ro_rw_zi
+    if s_rw is None:
+        return ro_rw_zi
+    if s_zi is not None:
+        return ro_rw_zi
+    s_zi = {
+        "sh_addr": s_rw["sh_addr"] + s_rw["sh_size"],
+        "sh_size": 0
+    }
+    return s_ro, s_rw, s_zi
+
+
+def _algo_check_for_section_problems(ro_rw_zi):
+    """Return a string describing any errors with the layout or None if good"""
+    s_ro, s_rw, s_zi = ro_rw_zi
+    if s_ro is None:
+        return "RO section is missing"
+    if s_rw is None:
+        return "RW section is missing"
+    if s_zi is None:
+        return "ZI section is missing"
+    if s_ro["sh_addr"] != 0:
+        return "RO section does not start at address 0"
+    if s_ro["sh_addr"] + s_ro["sh_size"] != s_rw["sh_addr"]:
+        return "RW section does not follow RO section"
+    if s_rw["sh_addr"] + s_rw["sh_size"] != s_zi["sh_addr"]:
+        return "ZI section does not follow RW section"
+    return None
+
+
+def _create_algo_bin(ro_rw_zi):
+    """Create a binary blob of the flash algo which can execute from ram"""
+    sect_ro, sect_rw, sect_zi = ro_rw_zi
+    algo_size = sect_ro["sh_size"] + sect_rw["sh_size"] + sect_zi["sh_size"]
+    algo_data = bytearray(algo_size)
+    for section in (sect_ro, sect_rw):
+        start = section["sh_addr"]
+        size = section["sh_size"]
+        data = section.data()
+        assert len(data) == size
+        algo_data[start:start + size] = data
+    return algo_data
+
+
+class PackFlashInfo(object):
+    """Wrapper class for the non-executable information in an FLM file"""
+
+    FLASH_DEVICE_STRUCT = "<H128sHLLLLBxxxLL"
+    FLASH_SECTORS_STRUCT = "<LL"
+    FLASH_SECTORS_STRUCT_SIZE = struct.calcsize(FLASH_SECTORS_STRUCT)
+    SECTOR_END = 0xFFFFFFFF
+
+    def __init__(self, elf_simple):
+        dev_info = elf_simple.symbols["FlashDevice"]
+        info_start = dev_info.value
+        info_size = struct.calcsize(self.FLASH_DEVICE_STRUCT)
+        data = elf_simple.read(info_start, info_size)
+        values = struct.unpack(self.FLASH_DEVICE_STRUCT, data)
+
+        self.version = values[0]
+        self.name = values[1].strip("\x00")
+        self.type = values[2]
+        self.start = values[3]
+        self.size = values[4]
+        self.page_size = values[5]
+        self.value_empty = values[7]
+        self.prog_timeout_ms = values[8]
+        self.erase_timeout_ms = values[9]
+
+        sector_gen = self._sector_and_sz_itr(elf_simple,
+                                             info_start + info_size)
+        self.sector_info_list = list(sector_gen)
+
+    def __str__(self):
+        desc = ""
+        desc += "Flash Device:" + os.linesep
+        desc += "  name=%s" % self.name + os.linesep
+        desc += "  version=0x%x" % self.version + os.linesep
+        desc += "  type=%i" % self.type + os.linesep
+        desc += "  start=0x%x" % self.start + os.linesep
+        desc += "  size=0x%x" % self.size + os.linesep
+        desc += "  page_size=0x%x" % self.page_size + os.linesep
+        desc += "  value_empty=0x%x" % self.value_empty + os.linesep
+        desc += "  prog_timeout_ms=%i" % self.prog_timeout_ms + os.linesep
+        desc += "  erase_timeout_ms=%i" % self.erase_timeout_ms + os.linesep
+        desc += "  sectors:" + os.linesep
+        for sector_start, sector_size in self.sector_info_list:
+            desc += ("    start=0x%x, size=0x%x" %
+                     (sector_start, sector_size) + os.linesep)
+        return desc
+
+    def _sector_and_sz_itr(self, elf_simple, data_start):
+        """Iterator which returns starting address and sector size"""
+        for entry_start in count(data_start, self.FLASH_SECTORS_STRUCT_SIZE):
+            data = elf_simple.read(entry_start, self.FLASH_SECTORS_STRUCT_SIZE)
+            size, start = struct.unpack(self.FLASH_SECTORS_STRUCT, data)
+            start_and_size = start, size
+            if start_and_size == (self.SECTOR_END, self.SECTOR_END):
+                return
+            yield start_and_size
+
+
+SymbolSimple = namedtuple("SymbolSimple", "name, value, size")
+
+
+class ElfFileSimple(ELFFile):
+    """Wrapper for elf object which allows easy access to symbols and rom"""
+
+    def __init__(self, data):
+        """Construct a ElfFileSimple from bytes or a bytearray"""
+        super(ElfFileSimple, self).__init__(StringIO.StringIO(data))
+        self.symbols = self._read_symbol_table()
+
+    def _read_symbol_table(self):
+        """Read the symbol table into the field "symbols" for easy use"""
+        section = self.get_section_by_name(b".symtab")
+        if not section:
+            raise Exception("Missing symbol table")
+
+        if not isinstance(section, SymbolTableSection):
+            raise Exception("Invalid symbol table section")
+
+        symbols = {}
+        for symbol in section.iter_symbols():
+            name_str = bytes2str(symbol.name)
+            if name_str in symbols:
+                logging.debug("Duplicate symbol %s", name_str)
+            symbols[name_str] = SymbolSimple(name_str, symbol["st_value"],
+                                             symbol["st_size"])
+        return symbols
+
+    def read(self, addr, size):
+        """Read program data from the elf file
+
+        :param addr: physical address (load address) to read from
+        :param size: number of bytes to read
+        :return: Requested data or None if address is unmapped
+        """
+        for segment in self.iter_segments():
+            seg_addr = segment["p_paddr"]
+            seg_size = min(segment["p_memsz"], segment["p_filesz"])
+            if addr >= seg_addr + seg_size:
+                continue
+            if addr + size <= seg_addr:
+                continue
+            # There is at least some overlap
+
+            if addr >= seg_addr and addr + size <= seg_addr + seg_size:
+                # Region is fully contained
+                data = segment.data()
+                start = addr - seg_addr
+                return data[start:start + size]
+
+
+if __name__ == '__main__':
+    main()