u-boot/tools/binman/state.py
Simon Glass e0e5df9310 binman: Support hashing entries
Sometimesi it us useful to be able to verify the content of entries with
a hash. Add an easy way to do this in binman. The hash information can be
retrieved from the device tree at run time.

Signed-off-by: Simon Glass <sjg@chromium.org>
2018-09-29 11:49:35 -06:00

253 lines
7 KiB
Python

# SPDX-License-Identifier: GPL-2.0+
# Copyright 2018 Google, Inc
# Written by Simon Glass <sjg@chromium.org>
#
# Holds and modifies the state information held by binman
#
import hashlib
import re
from sets import Set
import os
import tools
# Records the device-tree files known to binman, keyed by filename (e.g.
# 'u-boot-spl.dtb')
fdt_files = {}
# Arguments passed to binman to provide arguments to entries
entry_args = {}
# True to use fake device-tree files for testing (see U_BOOT_DTB_DATA in
# ftest.py)
use_fake_dtb = False
# Set of all device tree files references by images
fdt_set = Set()
# Same as above, but excluding the main one
fdt_subset = Set()
# The DTB which contains the full image information
main_dtb = None
def GetFdt(fname):
"""Get the Fdt object for a particular device-tree filename
Binman keeps track of at least one device-tree file called u-boot.dtb but
can also have others (e.g. for SPL). This function looks up the given
filename and returns the associated Fdt object.
Args:
fname: Filename to look up (e.g. 'u-boot.dtb').
Returns:
Fdt object associated with the filename
"""
return fdt_files[fname]
def GetFdtPath(fname):
"""Get the full pathname of a particular Fdt object
Similar to GetFdt() but returns the pathname associated with the Fdt.
Args:
fname: Filename to look up (e.g. 'u-boot.dtb').
Returns:
Full path name to the associated Fdt
"""
return fdt_files[fname]._fname
def GetFdtContents(fname):
"""Looks up the FDT pathname and contents
This is used to obtain the Fdt pathname and contents when needed by an
entry. It supports a 'fake' dtb, allowing tests to substitute test data for
the real dtb.
Args:
fname: Filename to look up (e.g. 'u-boot.dtb').
Returns:
tuple:
pathname to Fdt
Fdt data (as bytes)
"""
if fname in fdt_files and not use_fake_dtb:
pathname = GetFdtPath(fname)
data = GetFdt(fname).GetContents()
else:
pathname = tools.GetInputFilename(fname)
data = tools.ReadFile(pathname)
return pathname, data
def SetEntryArgs(args):
"""Set the value of the entry args
This sets up the entry_args dict which is used to supply entry arguments to
entries.
Args:
args: List of entry arguments, each in the format "name=value"
"""
global entry_args
entry_args = {}
if args:
for arg in args:
m = re.match('([^=]*)=(.*)', arg)
if not m:
raise ValueError("Invalid entry arguemnt '%s'" % arg)
entry_args[m.group(1)] = m.group(2)
def GetEntryArg(name):
"""Get the value of an entry argument
Args:
name: Name of argument to retrieve
Returns:
String value of argument
"""
return entry_args.get(name)
def Prepare(images, dtb):
"""Get device tree files ready for use
This sets up a set of device tree files that can be retrieved by GetFdts().
At present there is only one, that for U-Boot proper.
Args:
images: List of images being used
dtb: Main dtb
"""
global fdt_set, fdt_subset, fdt_files, main_dtb
# Import these here in case libfdt.py is not available, in which case
# the above help option still works.
import fdt
import fdt_util
# If we are updating the DTBs we need to put these updated versions
# where Entry_blob_dtb can find them. We can ignore 'u-boot.dtb'
# since it is assumed to be the one passed in with options.dt, and
# was handled just above.
main_dtb = dtb
fdt_files.clear()
fdt_files['u-boot.dtb'] = dtb
fdt_subset = Set()
if not use_fake_dtb:
for image in images.values():
fdt_subset.update(image.GetFdtSet())
fdt_subset.discard('u-boot.dtb')
for other_fname in fdt_subset:
infile = tools.GetInputFilename(other_fname)
other_fname_dtb = fdt_util.EnsureCompiled(infile)
out_fname = tools.GetOutputFilename('%s.out' %
os.path.split(other_fname)[1])
tools.WriteFile(out_fname, tools.ReadFile(other_fname_dtb))
other_dtb = fdt.FdtScan(out_fname)
fdt_files[other_fname] = other_dtb
def GetFdts():
"""Yield all device tree files being used by binman
Yields:
Device trees being used (U-Boot proper, SPL, TPL)
"""
yield main_dtb
for other_fname in fdt_subset:
yield fdt_files[other_fname]
def GetUpdateNodes(node):
"""Yield all the nodes that need to be updated in all device trees
The property referenced by this node is added to any device trees which
have the given node. Due to removable of unwanted notes, SPL and TPL may
not have this node.
Args:
node: Node object in the main device tree to look up
Yields:
Node objects in each device tree that is in use (U-Boot proper, which
is node, SPL and TPL)
"""
yield node
for dtb in fdt_files.values():
if dtb != node.GetFdt():
other_node = dtb.GetNode(node.path)
if other_node:
yield other_node
def AddZeroProp(node, prop):
"""Add a new property to affected device trees with an integer value of 0.
Args:
prop_name: Name of property
"""
for n in GetUpdateNodes(node):
n.AddZeroProp(prop)
def AddSubnode(node, name):
"""Add a new subnode to a node in affected device trees
Args:
node: Node to add to
name: name of node to add
Returns:
New subnode that was created in main tree
"""
first = None
for n in GetUpdateNodes(node):
subnode = n.AddSubnode(name)
if not first:
first = subnode
return first
def AddString(node, prop, value):
"""Add a new string property to affected device trees
Args:
prop_name: Name of property
value: String value (which will be \0-terminated in the DT)
"""
for n in GetUpdateNodes(node):
n.AddString(prop, value)
def SetInt(node, prop, value):
"""Update an integer property in affected device trees with an integer value
This is not allowed to change the size of the FDT.
Args:
prop_name: Name of property
"""
for n in GetUpdateNodes(node):
n.SetInt(prop, value)
def CheckAddHashProp(node):
hash_node = node.FindNode('hash')
if hash_node:
algo = hash_node.props.get('algo')
if not algo:
return "Missing 'algo' property for hash node"
if algo.value == 'sha256':
size = 32
else:
return "Unknown hash algorithm '%s'" % algo
for n in GetUpdateNodes(hash_node):
n.AddEmptyProp('value', size)
def CheckSetHashValue(node, get_data_func):
hash_node = node.FindNode('hash')
if hash_node:
algo = hash_node.props.get('algo').value
if algo == 'sha256':
m = hashlib.sha256()
m.update(get_data_func())
data = m.digest()
for n in GetUpdateNodes(hash_node):
n.SetData('value', data)