adt.py: Add basic ADT parser

Signed-off-by: Hector Martin <marcan@marcan.st>

proxyclient/adt.py

@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: MIT
+from construct import *
+
+ADTPropertyStruct = Struct(
+    "name" / PaddedString(32, "ascii"),
+    "size" / Int32ul,
+    "value" / Bytes(this.size & 0x7fffffff)
+)
+
+ADTNodeStruct = Struct(
+    "property_count" / Int32ul,
+    "child_count" / Int32ul,
+    "properties" / Array(this.property_count, Aligned(4, ADTPropertyStruct)),
+    "children" / Array(this.child_count, LazyBound(lambda: ADTNodeStruct))
+)
+
+ADTStringList = GreedyRange(CString("ascii"))
+
+ADT2Tuple = Array(2, Int64ul)
+
+STD_PROPERTIES = {
+    "compatible": ADTStringList,
+    "model": CString("ascii"),
+    "#size-cells": Int32ul,
+    "#address-cells": Int32ul,
+}
+
+def parse_prop(path, name, v):
+    if name in STD_PROPERTIES:
+        return STD_PROPERTIES[name].parse(v)
+
+    if v and v[-1] == 0 and all(0x20 <= i <= 0x7e for i in v[:-1]):
+        return CString("ascii").parse(v)
+
+    if len(v) == 4:
+        return Int32ul.parse(v)
+
+    if len(v) == 8:
+        return Int64ul.parse(v)
+
+    if len(v) == 16 and all(v[i] == 0 for i in (6, 7, 14, 15)):
+        return ADT2Tuple.parse(v)
+
+    return v
+
+class ADTNode:
+    def __init__(self, val=None, path="/"):
+        self.name = None
+        self.children = []
+        self.properties = {}
+
+
+
+        if val is not None:
+            for p in val.properties:
+                if p.name == "name":
+                    self.name = p.value.decode("ascii").rstrip("\0")
+                    break
+            else:
+                raise ValueError(f"Node in {path} has no name!")
+
+            self.path = path + self.name
+
+            for p in val.properties:
+                if p.name == "name":
+                    continue
+                self.properties[p.name] = parse_prop(self.path, p.name, p.value)
+
+            for c in val.children:
+                self.children.append(ADTNode(c, f"{self.path}/"))
+
+    def __getitem__(self, item):
+        if isinstance(item, str):
+            for i in self.children:
+                if i.name == item:
+                    return i
+            raise KeyError(f"Child node '{item}' not found")
+        return self.children[item]
+
+    def __getattr__(self, attr):
+        attr = attr.replace("_", "-")
+        return self.properties[attr]
+
+    def __str__(self, t=""):
+        return "\n".join([
+            t + f"{self.name} {{",
+            *(t + f"    {k} = {repr(v)}" for k, v in self.properties.items()),
+            "",
+            *(i.__str__(t + "    ") for i in self.children),
+            t+ "}"
+        ])
+
+    def __iter__(self):
+        return iter(self.children)
+
+def load_adt(data):
+    return ADTNode(ADTNodeStruct.parse(data))
+
+if __name__ == "__main__":
+    import sys
+    adt_data = open(sys.argv[1], "rb").read()
+    adt = load_adt(adt_data)
+    print(adt)