9fc6ebd8fe
Drop a few more Python 2 relics that are no-longer needed. Signed-off-by: Simon Glass <sjg@chromium.org>
119 lines
3.3 KiB
Python
119 lines
3.3 KiB
Python
# SPDX-License-Identifier: GPL-2.0+
|
|
# Copyright (c) 2018 Google, Inc
|
|
# Written by Simon Glass <sjg@chromium.org>
|
|
#
|
|
# Support for flashrom's FMAP format. This supports a header followed by a
|
|
# number of 'areas', describing regions of a firmware storage device,
|
|
# generally SPI flash.
|
|
|
|
import collections
|
|
import struct
|
|
import sys
|
|
|
|
from patman import tools
|
|
|
|
# constants imported from lib/fmap.h
|
|
FMAP_SIGNATURE = b'__FMAP__'
|
|
FMAP_VER_MAJOR = 1
|
|
FMAP_VER_MINOR = 0
|
|
FMAP_STRLEN = 32
|
|
|
|
FMAP_AREA_STATIC = 1 << 0
|
|
FMAP_AREA_COMPRESSED = 1 << 1
|
|
FMAP_AREA_RO = 1 << 2
|
|
|
|
FMAP_HEADER_LEN = 56
|
|
FMAP_AREA_LEN = 42
|
|
|
|
FMAP_HEADER_FORMAT = '<8sBBQI%dsH'% (FMAP_STRLEN)
|
|
FMAP_AREA_FORMAT = '<II%dsH' % (FMAP_STRLEN)
|
|
|
|
FMAP_HEADER_NAMES = (
|
|
'signature',
|
|
'ver_major',
|
|
'ver_minor',
|
|
'base',
|
|
'image_size',
|
|
'name',
|
|
'nareas',
|
|
)
|
|
|
|
FMAP_AREA_NAMES = (
|
|
'offset',
|
|
'size',
|
|
'name',
|
|
'flags',
|
|
)
|
|
|
|
# These are the two data structures supported by flashrom, a header (which
|
|
# appears once at the start) and an area (which is repeated until the end of
|
|
# the list of areas)
|
|
FmapHeader = collections.namedtuple('FmapHeader', FMAP_HEADER_NAMES)
|
|
FmapArea = collections.namedtuple('FmapArea', FMAP_AREA_NAMES)
|
|
|
|
|
|
def NameToFmap(name):
|
|
if type(name) == bytes:
|
|
name = name.decode('utf-8')
|
|
return name.replace('\0', '').replace('-', '_').upper()
|
|
|
|
def ConvertName(field_names, fields):
|
|
"""Convert a name to something flashrom likes
|
|
|
|
Flashrom requires upper case, underscores instead of hyphens. We remove any
|
|
null characters as well. This updates the 'name' value in fields.
|
|
|
|
Args:
|
|
field_names: List of field names for this struct
|
|
fields: Dict:
|
|
key: Field name
|
|
value: value of that field (string for the ones we support)
|
|
"""
|
|
name_index = field_names.index('name')
|
|
fields[name_index] = tools.ToBytes(NameToFmap(fields[name_index]))
|
|
|
|
def DecodeFmap(data):
|
|
"""Decode a flashmap into a header and list of areas
|
|
|
|
Args:
|
|
data: Data block containing the FMAP
|
|
|
|
Returns:
|
|
Tuple:
|
|
header: FmapHeader object
|
|
List of FmapArea objects
|
|
"""
|
|
fields = list(struct.unpack(FMAP_HEADER_FORMAT, data[:FMAP_HEADER_LEN]))
|
|
ConvertName(FMAP_HEADER_NAMES, fields)
|
|
header = FmapHeader(*fields)
|
|
areas = []
|
|
data = data[FMAP_HEADER_LEN:]
|
|
for area in range(header.nareas):
|
|
fields = list(struct.unpack(FMAP_AREA_FORMAT, data[:FMAP_AREA_LEN]))
|
|
ConvertName(FMAP_AREA_NAMES, fields)
|
|
areas.append(FmapArea(*fields))
|
|
data = data[FMAP_AREA_LEN:]
|
|
return header, areas
|
|
|
|
def EncodeFmap(image_size, name, areas):
|
|
"""Create a new FMAP from a list of areas
|
|
|
|
Args:
|
|
image_size: Size of image, to put in the header
|
|
name: Name of image, to put in the header
|
|
areas: List of FmapArea objects
|
|
|
|
Returns:
|
|
String containing the FMAP created
|
|
"""
|
|
def _FormatBlob(fmt, names, obj):
|
|
params = [getattr(obj, name) for name in names]
|
|
ConvertName(names, params)
|
|
return struct.pack(fmt, *params)
|
|
|
|
values = FmapHeader(FMAP_SIGNATURE, 1, 0, 0, image_size, name, len(areas))
|
|
blob = _FormatBlob(FMAP_HEADER_FORMAT, FMAP_HEADER_NAMES, values)
|
|
for area in areas:
|
|
blob += _FormatBlob(FMAP_AREA_FORMAT, FMAP_AREA_NAMES, area)
|
|
return blob
|