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BaseTools: Scripts: efi_debugging.py: search for EFI_SYSTEM_TABLE_POINTER

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Add code to search for gST via EFI_SYSTEM_TABLE_POINTER.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
This commit is contained in:
Ying-Chun Liu (PaulLiu) 2025-04-18 15:37:09 +01:00 • committed by mergify[bot]
parent 55b4688157
commit d985bd4b97
1 changed files with 34 additions and 2 deletions
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36
BaseTools/Scripts/efi_debugging.py
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@ -33,6 +33,7 @@ import os
import uuid
import struct
import re
import zlib
from ctypes import c_char, c_uint8, c_uint16, c_uint32, c_uint64, c_void_p
from ctypes import ARRAY, sizeof
from ctypes import Structure, LittleEndianStructure
@ -1770,8 +1771,10 @@ class EfiConfigurationTable:
def __init__(self, file, gST_addr=None):
self._file = file
if gST_addr is None:
# ToDo add code to search for gST via EFI_SYSTEM_TABLE_POINTER
return
# search for gST via EFI_SYSTEM_TABLE_POINTER
system_table_pointer = self._get_system_table_pointer()
if not system_table_pointer is None:
gST_addr = system_table_pointer.EfiSystemTableBase
gST = self._ctype_read(EFI_SYSTEM_TABLE, gST_addr)
self.read_efi_config_table(gST.NumberOfTableEntries,
@ -1796,6 +1799,35 @@ class EfiConfigurationTable:
data = self._file.read(sizeof(ctype_struct))
return ctype_struct.from_buffer(bytearray(data))
def _get_system_table_pointer(self):
start_addr = 0x0
end_addr = 0xf0000000
alignment = 0x00400000
# The translation of "IBI SYST" for the signature of EFI_SYSTEM_TABLE
efi_system_table_signature = 0x5453595320494249
system_table_pointer = None
current_addr = start_addr
while current_addr < end_addr:
try:
self._file.seek(current_addr)
data = self._file.read(sizeof(EFI_SYSTEM_TABLE_POINTER))
except:
current_addr = current_addr + alignment
continue
system_table_pointer = EFI_SYSTEM_TABLE_POINTER.from_buffer(bytearray(data))
if system_table_pointer.Signature == efi_system_table_signature:
buf1 = bytearray(system_table_pointer)[:16]
crc32_value = zlib.crc32(buf1)
crc32_value = zlib.crc32(b'\0' * (sizeof(EFI_SYSTEM_TABLE_POINTER) - len(buf1)), crc32_value)
if crc32_value == system_table_pointer.Crc32:
break
system_table_pointer = None
current_addr = current_addr + alignment
return system_table_pointer
@ classmethod
def read_efi_config_table(cls, table_cnt, table_ptr, ctype_read):
'''Create a dictionary of EFI Configuration table entries'''