board_inspector/memmapparser: add parser of e820 memory maps

This patch adds a parser of the physical E820 memory maps fetched from
/sys/firmware/memmap.

Tracked-On: #5922
Signed-off-by: Junjie Mao <junjie.mao@intel.com>

misc/config_tools/board_inspector/memmapparser/__init__.py

@@ -0,0 +1,6 @@
+# Copyright (C) 2021 Intel Corporation. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+from memmapparser.e820 import parse_e820

misc/config_tools/board_inspector/memmapparser/e820.py

@@ -0,0 +1,47 @@
+# Copyright (C) 2021 Intel Corporation. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import os
+from collections import namedtuple
+
+E820_TYPE_RAM = 1
+E820_TYPE_RESERVED = 2
+E820_TYPE_ACPI = 3
+E820_TYPE_NVS = 4
+E820_TYPE_UNKNOWN = 0xff
+
+name_of_types = {
+    E820_TYPE_RAM: "System RAM",
+    E820_TYPE_RESERVED: "Reserved",
+    E820_TYPE_ACPI: "ACPI Tables",
+    E820_TYPE_NVS: "ACPI Non-volatile Storage",
+    E820_TYPE_UNKNOWN: "Unknown E820 type",
+}
+
+type_of_names = { v: k for (k,v) in name_of_types.items() }
+
+class E820Entry(namedtuple("E820Entry", ["start", "end", "type"])):
+    def __repr__(self):
+        return "{0}(start=0x{1:016x}, end=0x{2:016x}, type='{3}')".format(
+            self.__class__.__name__, self.start, self.end, name_of_types.get(self.type))
+
+sysfs_memmap_path = "/sys/firmware/memmap"
+
+def read_file(path):
+    with open(path, "r") as f:
+        return f.read()
+    return ""
+
+def parse_e820():
+    acc = list()
+
+    for i in os.listdir(sysfs_memmap_path):
+        start = int(read_file(os.path.join(sysfs_memmap_path, i, "start")), base=16)
+        end = int(read_file(os.path.join(sysfs_memmap_path, i, "end")), base=16)
+        type_name = read_file(os.path.join(sysfs_memmap_path, i, "type")).strip()
+        ty = type_of_names.get(type_name, E820_TYPE_UNKNOWN)
+        acc.append(E820Entry(start, end, ty))
+
+    return sorted(acc, key=lambda x: x.start)