@ -13,12 +13,67 @@ import typing
import math
import struct
from dataclasses import dataclass
from functools import reduce
from pathlib import Path
from tlc . te import TransferEntry
TRANSFER_LIST_ENABLE_CHECKSUM = 0b1
# Description of each TE type. For each TE, there is a tag ID, a format (to be
# used in struct.pack to encode the TE), and a list of field names that can
# appear in the yaml file for that TE. Some fields are missing, if that TE has
# to be processed differently, or if it can only be added with a blob file.
transfer_entry_formats = {
0 : {
" tag_name " : " empty " ,
" format " : " 4x " ,
" fields " : [ ] ,
} ,
1 : {
" tag_name " : " fdt " ,
} ,
2 : {
" tag_name " : " hob_block " ,
} ,
3 : {
" tag_name " : " hob_list " ,
} ,
4 : {
" tag_name " : " acpi_table_aggregate " ,
} ,
5 : {
" tag_name " : " tpm_event_log_table " ,
" fields " : [ " event_log " , " flags " ] ,
} ,
6 : {
" tag_name " : " tpm_crb_base_address_table " ,
" format " : " QI " ,
" fields " : [ " crb_base_address " , " crb_size " ] ,
} ,
0x100 : {
" tag_name " : " optee_pageable_part " ,
" format " : " Q " ,
" fields " : [ " pp_addr " ] ,
} ,
0x101 : {
" tag_name " : " dt_spmc_manifest " ,
} ,
0x102 : {
" tag_name " : " exec_ep_info " ,
" format " : " 2BHIQI4x8Q " ,
" fields " : [ " ep_info " ] ,
} ,
0x104 : {
" tag_name " : " sram_layout " ,
" format " : " 2Q " ,
" fields " : [ " addr " , " size " ] ,
} ,
}
tag_name_to_tag_id = {
te [ " tag_name " ] : tag_id for tag_id , te in transfer_entry_formats . items ( )
}
class TransferList :
""" Class representing a Transfer List based on version 1.0 of the Firmware Handoff specification. """
@ -96,6 +151,28 @@ class TransferList:
return tl
@classmethod
def from_dict ( cls , config : dict ) :
""" Create a TL from data in a dictionary
The dictionary should have the same format as the yaml config files .
See the readme for more detail .
: param config : Dictionary containing the data described above .
"""
# get settings from config and set defaults
max_size = config . get ( " max_size " , 0x1000 )
has_checksum = config . get ( " has_checksum " , True )
flags = TRANSFER_LIST_ENABLE_CHECKSUM if has_checksum else 0
tl = cls ( max_size , flags )
for entry in config [ " entries " ] :
tl . add_transfer_entry_from_dict ( entry )
return tl
def header_to_bytes ( self ) - > bytes :
return struct . pack (
self . encoding ,
@ -141,6 +218,106 @@ class TransferList:
self . update_checksum ( )
return te
def add_transfer_entry_from_struct_format (
self , tag_id : int , struct_format : str , * args
) :
struct_format = " < " + struct_format
data = struct . pack ( struct_format , * args )
return self . add_transfer_entry ( tag_id , data )
def add_entry_point_info_transfer_entry ( self , entry : dict ) - > " TransferEntry " :
""" Add entry_point_info transfer entry
: param entry : Dictionary of the transfer entry , in the same format as
the YAML file .
"""
ep_info = entry [ " ep_info " ]
header = ep_info [ " h " ]
# size of the entry_point_info struct
entry_point_size = 88
attr = header [ " attr " ]
if type ( attr ) is str :
# convert string of flags names to an integer
# bit number | 0 | 1 |
# ------------|-----------------------|----------------------|
# 0 | secure | non-secure |
# 1 | little endian | big-endian |
# 2 | disable secure timer | enable secure timer |
# 3 | executable | non-executable |
# 4 | first exe | not first exe |
#
# Bit 5 and bit 0 are used to determine the security state.
flag_names = {
" EP_SECURE " : 0x0 ,
" EP_NON_SECURE " : 0x1 ,
" EP_REALM " : 0x21 ,
" EP_EE_LITTLE " : 0x0 ,
" EP_EE_BIG " : 0x2 ,
" EP_ST_DISABLE " : 0x0 ,
" EP_ST_ENABLE " : 0x4 ,
" EP_NON_EXECUTABLE " : 0x0 ,
" EP_EXECUTABLE " : 0x8 ,
" EP_FIRST_EXE " : 0x10 ,
}
# create list of integer flags, then bitwise-or them together
flags = [ flag_names [ f . strip ( ) ] for f in attr . split ( " | " ) ]
attr = reduce ( lambda x , y : x | y , flags )
return self . add_transfer_entry_from_struct_format (
0x102 ,
transfer_entry_formats [ 0x102 ] [ " format " ] ,
header [ " type " ] ,
header [ " version " ] ,
entry_point_size ,
attr ,
ep_info [ " pc " ] ,
ep_info [ " spsr " ] ,
* ep_info [ " args " ] ,
)
def add_transfer_entry_from_dict (
self ,
entry : dict ,
) - > " TransferEntry " :
""" Add a transfer entry from data in a dictionary
The dictionary should have the same format as the entries in the yaml
config files . See the readme for more detail .
: param entry : Dictionary containing the data described above .
"""
# Tag_id is either a tag name or a tag id. Use it to get the TE format.
tag_id = entry [ " tag_id " ]
if tag_id in tag_name_to_tag_id :
tag_id = tag_name_to_tag_id [ tag_id ]
te_format = transfer_entry_formats [ tag_id ]
tag_name = te_format [ " tag_name " ]
if " blob_file_path " in entry :
return self . add_transfer_entry_from_file ( tag_id , entry [ " blob_file_path " ] )
elif tag_name == " tpm_event_log_table " :
with open ( entry [ " event_log " ] , " rb " ) as f :
event_log_data = f . read ( )
flags_bytes = entry [ " flags " ] . to_bytes ( 4 , " little " )
data = flags_bytes + event_log_data
return self . add_transfer_entry ( tag_id , data )
elif tag_name == " exec_ep_info " :
return self . add_entry_point_info_transfer_entry ( entry )
elif " format " in te_format and " fields " in te_format :
fields = [ entry [ field ] for field in te_format [ " fields " ] ]
return self . add_transfer_entry_from_struct_format (
tag_id , te_format [ " format " ] , * fields
)
else :
raise ValueError ( f " Invalid transfer entry { entry } . " )
def add_transfer_entry_from_file ( self , tag_id : int , path : Path ) - > " TransferEntry " :
with open ( path , " rb " ) as f :
return self . add_transfer_entry ( tag_id , f . read ( ) )
Manish Pandey
3 months ago
TrustedFirmware Code Review
