Add big-endian support in the patchmaker. Also add ARM BE8 support (#284

) * Add big-endian support in the patchmaker. Also add ARM BE8 support * Update changelogs * Moved big endian flags from abstract to ARM toolchain * Added tests for ARM big endian and BE8 modes * Linter * Added missing import * Fix import * Fixed alignement test for big-endian --------- Co-authored-by: Paul Noalhyt <[email protected]>
redballoonsecurity · Dec 4, 2024 · 54c2956 · 54c2956
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Showing 6 changed files with 44 additions and 3 deletions.
diff --git a/ofrak_patch_maker/CHANGELOG.md b/ofrak_patch_maker/CHANGELOG.md
@@ -44,6 +44,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Extend parsed symbol dictionary to include LinkableSymbolType.
 - Extend AssembledObject and BOM types to include relocation and unresolved symbols.
 - Add separate data sections support to LLVM toolchain, and add general flag for including subsections
+- Add support for big endian in the GNU toolchain
+- Add support for ARM BE8 in the GNU toolchain
 
 ### Changed
 - Switch to standard GCC-like frontend for LLVM, which supports C attribute(weak)

diff --git a/ofrak_patch_maker/ofrak_patch_maker/toolchain/gnu.py b/ofrak_patch_maker/ofrak_patch_maker/toolchain/gnu.py
@@ -46,7 +46,6 @@ def __init__(
                 #      if sections contain more than one function =/
                 "-fno-merge-constants",  # avoids sections like .rodata.cst16, .rodata.str1.1 etc
                 "-fno-reorder-functions",
-                "-Wall",
             ]
         )
         if self._config.separate_data_sections:

diff --git a/ofrak_patch_maker/ofrak_patch_maker/toolchain/gnu_arm.py b/ofrak_patch_maker/ofrak_patch_maker/toolchain/gnu_arm.py
@@ -1,7 +1,8 @@
 from ofrak_patch_maker.binary_parser.gnu import GNU_ELF_Parser
 from ofrak_patch_maker.toolchain.gnu import GNU_10_Toolchain
 from ofrak_patch_maker.toolchain.model import ToolchainConfig, ToolchainException
-from ofrak_type.architecture import InstructionSet, SubInstructionSet, ArchInfo
+from ofrak_type.architecture import InstructionSet, SubInstructionSet, ArchInfo, ProcessorType
+from ofrak_type.endianness import Endianness
 import logging
 
 
@@ -19,6 +20,13 @@ def __init__(
             self._compiler_flags.append("-mfloat-abi=hard")
         else:
             self._compiler_flags.append("-msoft-float")
+        if self._processor.processor == ProcessorType.GENERIC_ARM_BE8:
+            self._compiler_flags.append("-mbe8")
+            self._linker_flags.append("-be8")
+        if self._processor.endianness == Endianness.BIG_ENDIAN:
+            self._compiler_flags.append("-mbig-endian")
+            self._linker_flags.append("-EB")
+            self._assembler_flags.append("-mbig-endian")
 
     @property
     def name(self) -> str:

diff --git a/ofrak_patch_maker/ofrak_patch_maker_test/test_arm_toolchain.py b/ofrak_patch_maker/ofrak_patch_maker_test/test_arm_toolchain.py
@@ -46,6 +46,28 @@
             ),
             ARM_EXTENSION,
         ),
+        ToolchainUnderTest(
+            GNU_ARM_NONE_EABI_10_2_1_Toolchain,
+            ArchInfo(
+                InstructionSet.ARM,
+                SubInstructionSet.ARMv8A,
+                BitWidth.BIT_32,
+                Endianness.BIG_ENDIAN,
+                ProcessorType.GENERIC_A9_V7_THUMB,
+            ),
+            ARM_EXTENSION,
+        ),
+        ToolchainUnderTest(
+            GNU_ARM_NONE_EABI_10_2_1_Toolchain,
+            ArchInfo(
+                InstructionSet.ARM,
+                SubInstructionSet.ARMv8A,
+                BitWidth.BIT_32,
+                Endianness.BIG_ENDIAN,
+                ProcessorType.GENERIC_ARM_BE8,
+            ),
+            ARM_EXTENSION,
+        ),
         ToolchainUnderTest(
             LLVM_12_0_1_Toolchain,
             ArchInfo(
@@ -164,4 +186,12 @@ def test_arm_alignment(toolchain_under_test: ToolchainUnderTest):
     with open(exec_path, "rb") as f:
         dat = f.read()
         code_offset = code_segments[0].offset
-        assert dat[code_offset : code_offset + 2] == b"\x05\xe0"
+        if (
+            toolchain_under_test.proc.endianness == Endianness.LITTLE_ENDIAN
+            or toolchain_under_test.proc.processor == ProcessorType.GENERIC_ARM_BE8
+        ):
+            # little-endian code instructions
+            expected_bytes = b"\x05\xe0"
+        else:
+            expected_bytes = b"\xe0\x05"
+        assert dat[code_offset : code_offset + 2] == expected_bytes
diff --git a/ofrak_type/CHANGELOG.md b/ofrak_type/CHANGELOG.md
@@ -13,6 +13,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Added
 - `ProcessorType.CORTEX_A72`
 - LinkableSymbolType enum for generalized representation of symbol types (essentially functions vs. data)
+- Added a `GENERIC_ARM_BE8` ProcessorType for ARM BE8
 
 ## [2.1.0](https://github.com/redballoonsecurity/ofrak/compare/ofrak-type-v2.0.0...ofrak-type-v2.1.0) - 2023-01-20
 ### Added

diff --git a/ofrak_type/ofrak_type/architecture.py b/ofrak_type/ofrak_type/architecture.py
@@ -139,6 +139,7 @@ class ProcessorType(Enum):
     GENERIC_A9_V6 = "generic_a9_v6"
     GENERIC_A9_V7 = "generic_a9_v7"
     GENERIC_A9_V7_THUMB = "generic_a9_v7_thumb"
+    GENERIC_ARM_BE8 = "generic_be8"  # ARM with little endian code but big endian data
     MSP430 = "msp340"
     MIPS_LITTLE = "mips"
     MIPS_RM5721_BIG = "mips_rm5721_big"