Merge pull request #1574 from elicn/fix-qdb-cortexm

Fix qdb support for ARM Cortex-M

Author: xwings

qiling/debugger/qdb/arch/arch_arm.py

@@ -3,12 +3,14 @@
 # Cross Platform and Multi Architecture Advanced Binary Emulation Framework
 #
 
-from typing import Dict, Optional
+from typing import ClassVar, Dict, Optional
 
 from .arch import Arch
 
 
 class ArchARM(Arch):
+    _flags_reg: ClassVar[str] = 'cpsr'
+
     def __init__(self) -> None:
         regs = (
             'r0', 'r1', 'r2', 'r3',
@@ -134,6 +136,8 @@ def read_insn(self, address: int) -> Optional[bytearray]:
 
 
 class ArchCORTEX_M(ArchARM):
+    _flags_reg: ClassVar[str] = 'xpsr'
+
     def __init__(self):
         super().__init__()
 

qiling/debugger/qdb/branch_predictor/branch_predictor_arm.py

@@ -27,11 +27,11 @@ class BranchPredictorARM(BranchPredictor, ArchARM):
 
     stop = 'udf'
 
-    def get_cpsr(self) -> Tuple[bool, bool, bool, bool]:
-        """Get flags map of CPSR.
+    def get_cond_flags(self) -> Tuple[bool, bool, bool, bool]:
+        """Get condition status flags from CPSR / xPSR.
         """
 
-        cpsr = self.read_reg('cpsr')
+        cpsr = self.read_reg(self._flags_reg)
 
         return (
             (cpsr & (0b1 << 28)) != 0,  # V, overflow flag
@@ -122,9 +122,9 @@ def __parse_op(op: ArmOp, *args, **kwargs) -> Optional[int]:
 
         def __is_taken(cc: int) -> Tuple[bool, Tuple[bool, ...]]:
             pred = predicate[cc]
-            cpsr = self.get_cpsr()
+            flags = self.get_cond_flags()
 
-            return pred(*cpsr), cpsr
+            return pred(*flags), flags
 
         # conditions predicate selector
         predicate: Dict[int, Callable[..., bool]] = {
@@ -215,13 +215,13 @@ def __is_taken(cc: int) -> Tuple[bool, Tuple[bool, ...]]:
                     where = __parse_op(operands[1], **msize[suffix])
 
             elif iname in binop:
-                going, cpsr = __is_taken(insn.cc)
+                going, flags = __is_taken(insn.cc)
 
                 if going:
                     operator = binop[iname]
                     op1 = __parse_op(operands[1])
                     op2 = __parse_op(operands[2])
-                    carry = int(cpsr[1])
+                    carry = int(flags[1])
 
                     where = (op1 and op2) and operator(op1, op2, carry)
 

qiling/debugger/qdb/render/render_arm.py

@@ -3,7 +3,7 @@
 # Cross Platform and Multi Architecture Advanced Binary Emulation Framework
 #
 
-from typing import Iterator, Optional
+from typing import Iterator
 
 from .render import Render, ContextRender
 from ..arch import ArchARM, ArchCORTEX_M
@@ -15,7 +15,7 @@ class ContextRenderARM(ContextRender, ArchARM):
     """
 
     def print_mode_info(self) -> None:
-        cpsr = self.read_reg('cpsr')
+        cpsr = self.read_reg(self._flags_reg)
 
         flags = ArchARM.get_flags(cpsr)
         mode = ArchARM.get_mode(cpsr)