BaseTools: Scripts: efi_debugging.py: search for EFI_SYSTEM_TABLE_POINTER

Add code to search for gST via EFI_SYSTEM_TABLE_POINTER.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>

1 files changed, 34 insertions, 2 deletions

diff --git a/BaseTools/Scripts/efi_debugging.py b/BaseTools/Scripts/efi_debugging.py
index 9848cd5968..1c1446a878 100755
--- a/BaseTools/Scripts/efi_debugging.py
+++ b/BaseTools/Scripts/efi_debugging.py
@@ -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'''