From 858c177d1b96ad6306edcda744e49d0cee906aff Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Wed, 6 May 2026 06:34:29 +0000
Subject: debug: refactor dump_mb2i tool

---
 scripts/gdb/teachos/dump_mb2i.py | 199 ++++++++++++++++++++++++++-------------
 1 file changed, 135 insertions(+), 64 deletions(-)

(limited to 'scripts')

diff --git a/scripts/gdb/teachos/dump_mb2i.py b/scripts/gdb/teachos/dump_mb2i.py
index 41a2932..06f4531 100644
--- a/scripts/gdb/teachos/dump_mb2i.py
+++ b/scripts/gdb/teachos/dump_mb2i.py
@@ -1,30 +1,72 @@
 import gdb
 import struct
+from enum import IntEnum
+
+
+class TagType(IntEnum):
+    END = 0
+    CMDLINE = 1
+    BOOT_LOADER_NAME = 2
+    MODULE = 3
+    BASIC_MEMINFO = 4
+    BOOTDEV = 5
+    MMAP = 6
+    VBE = 7
+    FRAMEBUFFER = 8
+    ELF_SECTIONS = 9
+    APM = 10
+    EFI32_SYSTEM_TABLE_POINTER = 11
+    EFI64_SYSTEM_TABLE_POINTER = 12
+    SMBIOS_TABLES = 13
+    ACPI_OLD = 14
+    ACPI_NEW = 15
+    NETWORKING = 16
+    EFI_MEMORY_MAP = 17
+    EFI_BOOT_SERVICES_NOT_TERMINATED = 18
+    EFI32_IMAGE_HANDLE_POINTER = 19
+    EFI64_IMAGE_HANDLE_POINTER = 20
+    LOAD_BASE_ADDR = 21
+
+
+class MemoryType(IntEnum):
+    AVAILABLE = 1
+    RESERVED = 2
+    ACPI_RECLAIM = 3
+    NVS = 4
+    BAD = 5
 
 
 TAG_NAMES = {
-    0: "End of Tags",
-    1: "Boot Command Line",
-    2: "Boot Loader Name",
-    3: "Boot Module",
-    4: "Basic Memory Information",
-    5: "BIOS Boot Device",
-    6: "Memory Map",
-    7: "VBE Info",
-    8: "Framebuffer Info",
-    9: "ELF Symbols",
-    10: "APM Table",
-    14: "ACPI old RSDP (1.0)",
-    15: "ACPI new RSDP (2.0+)",
-    21: "Image Load Base Physical Address",
+    TagType.END: "End of Tags",
+    TagType.CMDLINE: "Boot Command Line",
+    TagType.BOOT_LOADER_NAME: "Boot Loader Name",
+    TagType.MODULE: "Boot Module",
+    TagType.BASIC_MEMINFO: "Basic Memory Information",
+    TagType.BOOTDEV: "BIOS Boot Device",
+    TagType.MMAP: "Memory Map",
+    TagType.VBE: "VBE Info",
+    TagType.FRAMEBUFFER: "Framebuffer Info",
+    TagType.ELF_SECTIONS: "ELF Symbols",
+    TagType.APM: "APM Table",
+    TagType.EFI32_SYSTEM_TABLE_POINTER: "EFI 32-bit System Table Pointer",
+    TagType.EFI64_SYSTEM_TABLE_POINTER: "EFI 64-bit System Table Pointer",
+    TagType.SMBIOS_TABLES: "SMBIOS Tables",
+    TagType.ACPI_OLD: "ACPI old RSDP (1.0)",
+    TagType.ACPI_NEW: "ACPI new RSDP (2.0+)",
+    TagType.NETWORKING: "Networking Information",
+    TagType.EFI_MEMORY_MAP: "EFI Memory Map",
+    TagType.EFI_BOOT_SERVICES_NOT_TERMINATED: "EFI Boot Services Not Terminated",
+    TagType.EFI32_IMAGE_HANDLE_POINTER: "EFI 32-bit Image Handle Pointer",
+    TagType.EFI64_IMAGE_HANDLE_POINTER: "EFI 64-bit Image Handle Pointer",
+    TagType.LOAD_BASE_ADDR: "Image Load Base Physical Address",
 }
 
 MEMORY_TYPES = {
-    1: "Available",
-    2: "Reserved",
-    3: "ACPI Reclaim",
-    4: "Non-volatile storage",
-    5: "Bad Memory",
+    MemoryType.AVAILABLE: "Available",
+    MemoryType.RESERVED: "Reserved",
+    MemoryType.ACPI_RECLAIM: "ACPI Reclaim",
+    MemoryType.NVS: "Non-volatile storage",
+    MemoryType.BAD: "Bad Memory",
 }
 
 INDENT = f"{' '*11}"
@@ -64,7 +106,9 @@ class DumpMB2I(gdb.Command):
             return
 
         if total_size < 8 or total_size > 1024 * 1024:
-            gdb.write("Warning: suspicious total size ({total_size} bytes). Aborting.")
+            gdb.write(
+                f"Warning: suspicious total size ({total_size} bytes). Aborting.\n"
+            )
             return
 
         gdb.write(f"+{'-'*70}+\n")
@@ -86,11 +130,11 @@ class DumpMB2I(gdb.Command):
                 )
                 break
 
-            self._print_tag(inferior, tag_address, tag_type, tag_size)
-
-            if tag_type == 0 and tag_size == 0:
+            if tag_type == TagType.END and tag_size == 8:
                 break
 
+            self._print_tag(inferior, tag_address, tag_type, tag_size)
+
             offset += (tag_size + 7) & ~7
 
     def _format_size(self, size):
@@ -104,50 +148,77 @@ class DumpMB2I(gdb.Command):
 
     def _print_tag(self, inferior, tag_address, tag_type, tag_size):
         name = TAG_NAMES.get(tag_type, f"Unknown Tag")
-        gdb.write(f"[Tag {tag_type:#04x}] {name} (size: {self._format_size(tag_size)})\n")
+        gdb.write(
+            f"[Tag {tag_type:#04x}] {name} (size: {self._format_size(tag_size)})\n"
+        )
 
-        if tag_size <= 8 and tag_type != 0:
+        if tag_size <= 8 and tag_type != TagType.END:
             return
 
         try:
-            if tag_type in (1, 2):
-                data = inferior.read_memory(tag_address + 8, tag_size - 8).tobytes()
-                text = data.split(b"\x00")[0].decode("ascii", "replace")
-                gdb.write(f'{INDENT}"{text}"\n')
-            elif tag_type == 3:
-                data = inferior.read_memory(tag_address + 8, tag_size - 8).tobytes()
-                start, end = struct.unpack_from("<II", data)
-                string = data[8:].split(b"\x00")[0].decode("ascii", "replace")
-                gdb.write(
-                    f"{INDENT}start: {start:#010x} | end: {end:#010x} | size: {self._format_size(end - start)}\n"
-                )
-                if string:
-                    gdb.write(f'{INDENT}string: "{string}"\n')
-            elif tag_type == 5:
-                data = inferior.read_memory(tag_address + 8, tag_size - 8).tobytes()
-                device, partition, sub_partition = struct.unpack_from("<III", data)
-                gdb.write(
-                    f"{INDENT}device: {device:#04x} | partition: {partition:#06x} | sub-partion: {sub_partition:#06x}\n"
-                )
-            elif tag_type == 6:
-                data = inferior.read_memory(tag_address + 8, tag_size - 8).tobytes()
-                entry_size, entry_version = struct.unpack_from("<II", data)
-                if entry_size < 24:
-                    return
-                num_entries = (tag_size - 16) // entry_size
-                for i in range(num_entries):
-                    entry_offset = 8 + i * entry_size
-                    base, length, memory_type = struct.unpack_from(
-                        "<QQI", data, entry_offset
-                    )
-                    type_string = MEMORY_TYPES.get(memory_type, "Unknown")
-                    gdb.write(
-                        f"{INDENT}[{i:02d}] {base:#018x} - {base + length:#018x} | {self._format_size(length)} | type: {type_string}\n"
-                    )
-            elif tag_type == 21:
-                data = inferior.read_memory(tag_address + 8, tag_size - 8).tobytes()
-                base = struct.unpack("<I", data)[0]
-                gdb.write(f"{INDENT}address: {base:#010x}\n")
+            data = inferior.read_memory(tag_address + 8, tag_size - 8).tobytes()
+
+            handlers = {
+                TagType.CMDLINE: self._write_string_tag,
+                TagType.BOOT_LOADER_NAME: self._write_string_tag,
+                TagType.MODULE: self._write_module_tag,
+                TagType.BASIC_MEMINFO: self._write_basic_memory_info_tag,
+                TagType.BOOTDEV: self._write_boot_device_tag,
+                TagType.MMAP: self._write_memory_map_tag,
+                TagType.LOAD_BASE_ADDR: self._write_image_load_base_physical_address_tag,
+                TagType.FRAMEBUFFER: self._write_framebuffer_info_tag,
+            }
+
+            handler = handlers.get(tag_type)
+            if handler:
+                handler(data)
 
         except Exception as e:
-            gdb.write(f"{INDENT}<failed to decode tag: {e}>\n")
+            gdb.write(
+                f"{INDENT}<failed to decode tag: {e} ({tag_type:#04x} | {tag_size:#06x})>\n"
+            )
+
+    def _write_string_tag(self, data):
+        text = data.split(b"\x00")[0].decode("ascii", "replace")
+        gdb.write(f'{INDENT}"{text}"\n')
+
+    def _write_module_tag(self, data):
+        start, end = struct.unpack_from("<II", data)
+        string = data[8:].split(b"\x00")[0].decode("ascii", "replace")
+        gdb.write(
+            f"{INDENT}start: {start:#010x} | end: {end:#010x} | size: {self._format_size(end - start)}\n"
+        )
+        if string:
+            gdb.write(f'{INDENT}string: "{string}"\n')
+
+    def _write_basic_memory_info_tag(self, data):
+        lower, upper = struct.unpack_from("<II", data)
+        gdb.write(
+            f"{INDENT}upper memory: {self._format_size(upper * 1024)} | lower memory: {self._format_size(lower * 1024)}\n"
+        )
+
+    def _write_boot_device_tag(self, data):
+        device, partition, sub_partition = struct.unpack_from("<III", data)
+        gdb.write(
+            f"{INDENT}device: {device:#04x} | partition: {partition:#06x} | sub-partition: {sub_partition:#06x}\n"
+        )
+
+    def _write_memory_map_tag(self, data):
+        entry_size, entry_version = struct.unpack_from("<II", data)
+        if entry_size < 24:
+            return
+        num_entries = (len(data) - 8) // entry_size
+        for i in range(num_entries):
+            entry_offset = 8 + i * entry_size
+            base, length, memory_type = struct.unpack_from("<QQI", data, entry_offset)
+            type_string = MEMORY_TYPES.get(memory_type, "Unknown")
+            gdb.write(
+                f"{INDENT}[{i:02d}] {base:#018x} - {base + length:#018x} | {self._format_size(length)} | type: {type_string}\n"
+            )
+
+    def _write_image_load_base_physical_address_tag(self, data):
+        base = struct.unpack("<I", data)[0]
+        gdb.write(f"{INDENT}address: {base:#010x}\n")
+
+    def _write_framebuffer_info_tag(self, data):
+        pass
-- 
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