board_inspector: add a visitor to generate AML binary from trees

This patch introduces a visitor that converts an arbitrary AML tree to an
AML binary. Most nodes can be converted in a straightforward way by
following the defined grammar, but the following nodes require some
additional effort:

  - NameStrings can be formatted as either a NameSeg (i.e. four upper case
    characters), a DualNamePath, a MultiNamePath or a NullName.

  - PkgLengths are recalculated according to the actual length of the
    following object (in case they are changed dynamically after being
    generated by the parser) and generated following the AML encoding of
    such lengths.

The visitor works in a bottom-up manner, i.e. the children are visited and
converted to binary before the parent.

The whole trees parsed from DSDT/SSDTs are now also stored in the Context
for further reference.

Tracked-On: #6287
Signed-off-by: Junjie Mao <junjie.mao@intel.com>

misc/config_tools/board_inspector/acpiparser/aml/context.py

@@ -142,6 +142,7 @@ class Context:
     def __init__(self):
         self.streams = {}
         self.current_stream = None
+        self.trees = {}
 
         # Loaded namespace
         self.__symbol_table = {}

misc/config_tools/board_inspector/acpiparser/aml/tree.py

@@ -63,6 +63,14 @@ class Visitor:
                 self.visit_topdown(child)
         self.depth -= 1
 
+    def visit_bottomup(self, tree):
+        self.depth += 1
+        for child in tree.children:
+            if isinstance(child, Tree):
+                self.visit_bottomup(child)
+        self.depth -= 1
+        self.__visit(tree)
+
 class Transformer:
     def __init__(self):
         self.depth = 0

misc/config_tools/board_inspector/acpiparser/aml/visitors.py

@@ -3,7 +3,10 @@
 # SPDX-License-Identifier: BSD-3-Clause
 #
 
+import sys
+
 from .tree import Visitor
+from . import grammar
 
 class PrintLayoutVisitor(Visitor):
     @staticmethod
@@ -69,3 +72,124 @@ class ConditionallyUnregisterSymbolVisitor(Visitor):
             self.depth -= 1
         elif tree.label not in ["DefMethod"]:
             super().visit_topdown(tree)
+
+class GenerateBinaryVisitor(Visitor):
+    def __init__(self):
+        super().__init__()
+
+    @staticmethod
+    def __format_length(length):
+        assert length <= 0x0FFFFFFF
+        if length <= 0x3F:
+            return length.to_bytes(1, sys.byteorder)
+        else:
+            first_byte_value = length & 0xF
+            rest_byte_value = length >> 4
+            if rest_byte_value <= 0xFF:
+                first_byte = (first_byte_value + (1 << 6)).to_bytes(1, sys.byteorder)
+                rest_bytes = rest_byte_value.to_bytes(1, sys.byteorder)
+            elif rest_byte_value <= 0xFFFF:
+                first_byte = (first_byte_value + (2 << 6)).to_bytes(1, sys.byteorder)
+                rest_bytes = rest_byte_value.to_bytes(2, sys.byteorder)
+            else:
+                first_byte = (first_byte_value + (3 << 6)).to_bytes(1, sys.byteorder)
+                rest_bytes = rest_byte_value.to_bytes(3, sys.byteorder)
+            return first_byte + rest_bytes
+
+    @staticmethod
+    def __format_pkg_length(length):
+        assert length <= 0x0FFFFFFB
+        if length <= 0x3E:
+            length += 1
+        elif length <= 0x0FFD:
+            length += 2
+        elif length <= 0x0FFFFC:
+            length += 3
+        else:
+            length += 4
+        return GenerateBinaryVisitor.__format_length(length)
+
+    def generate(self, tree):
+        self.acc = []
+        self.visit(tree)
+        assert len(self.acc) == 1
+        return self.acc.pop()
+
+    def ByteData(self, tree):
+        self.acc.append(tree.value.to_bytes(1, sys.byteorder))
+
+    def WordData(self, tree):
+        self.acc.append(tree.value.to_bytes(2, sys.byteorder))
+
+    def DWordData(self, tree):
+        self.acc.append(tree.value.to_bytes(4, sys.byteorder))
+
+    def TWordData(self, tree):
+        self.acc.append(tree.value.to_bytes(6, sys.byteorder))
+
+    def QWordData(self, tree):
+        self.acc.append(tree.value.to_bytes(8, sys.byteorder))
+
+    def NameSeg(self, tree):
+        name = tree.value[:4]
+        if len(name) < 4:
+            name += ("_" * (4 - len(name)))
+        self.acc.append(bytes(name, "ascii"))
+
+    def NameString(self, tree):
+        acc = bytearray()
+        segs = tree.value.lstrip("^\\")
+        if len(segs) < len(tree.value):
+            acc.extend(bytes(tree.value[:len(tree.value) - len(segs)], "ascii"))
+        if segs:
+            nr_dots = segs.count(".")
+            if nr_dots == 1:
+                acc.append(grammar.AML_DUAL_NAME_PREFIX)
+            elif nr_dots >= 2:
+                acc.append(grammar.AML_MULTI_NAME_PREFIX)
+                acc.append(nr_dots + 1)
+            acc.extend(bytes(segs.replace(".", ""), "ascii"))
+        else:
+            acc.append(grammar.AML_NULL_NAME)
+        self.acc.append(acc)
+
+    def String(self, tree):
+        acc = bytearray()
+        acc.append(grammar.AML_STRING_PREFIX)
+        acc.extend(bytes(tree.value, "latin-1"))
+        acc.append(0)
+        self.acc.append(acc)
+
+    def ByteList(self, tree):
+        self.acc.append(tree.value)
+
+    def PkgLength(self, tree):
+        pass
+
+    def FieldLength(self, tree):
+        self.acc.append(self.__format_length(tree.value))
+
+    def default(self, tree):
+        assert tree.structure and isinstance(tree.structure, tuple)
+        assert tree.structure != ("value",), f"{tree.label} is not expected to be handled by the default handler"
+
+        parts = []
+        for child in reversed(tree.children):
+            if child.label == "PkgLength":
+                if tree.label == "DefIfElse" and tree.DefElse:
+                    # The last component of a DefIfElse clause (i.e. DefElse) is not counted by the PkgLength of the
+                    # DefIfElse.
+                    length = sum(map(len, parts[1:]))
+                else:
+                    length = sum(map(len, parts))
+                parts.append(self.__format_pkg_length(length))
+            else:
+                parts.append(self.acc.pop())
+        if isinstance(tree.structure[0], int):
+            opcode = tree.structure[0]
+            if opcode <= 0xFF:
+                parts.append(opcode.to_bytes(1, sys.byteorder))
+            else:
+                parts.append(opcode.to_bytes(2, sys.byteorder))
+
+        self.acc.append(b''.join(reversed(parts)))

misc/config_tools/board_inspector/acpiparser/dsdt.py

@@ -21,7 +21,6 @@ def DSDT(val):
     tables = [val] + list(map(lambda x: os.path.join(table_dir, x), ssdt))
 
     context = Context()
-    trees = []
     try:
         for t in tables:
             logging.info(f"Loading {t}")
@@ -29,13 +28,13 @@ def DSDT(val):
             tree = Tree()
             AMLCode.parse(context, tree)
             tree = DeferredExpansion(context).transform_topdown(tree)
-            trees.append(tree)
+            context.trees[os.path.basename(t)] = tree
     except Exception as e:
         context.current_stream.dump()
         raise
 
     context.skip_external_on_lookup()
     visitor = ConditionallyUnregisterSymbolVisitor(ConcreteInterpreter(context))
-    for tree in trees:
+    for tree in context.trees.values():
         visitor.visit_topdown(tree)
     return context