DebugInfo

This repository regenerates debug information (like PDB) from LeviLamina's public data.

Background

• After 1.21.3.01, Mojang removed debug information from BDS.
• Mojang no longer provides any debugging information (both server and client) to the community.
• Mojang has an agreement with LiteLDev to provide them with debug data.
• LiteLDev generates header files and obfuscated symbol to RVA lookup tables from debug data and provides them to the community.

Problems caused by Mojang's collaboration with LiteLDev

• Mojang's collaboration with LiteLDev is opaque and we have no idea what they do.
• LiteLDev has completed its monopoly, and there will no longer be a second mod loader in the community.
• Due to the obfuscated format, the community can no longer reverse engineer BDS.

Header files, obfuscation format and security

• LeviLamina's design necessitates that they publish header files.
• The header file contains all the declaration information so that symbols can be generated.
• The RVA of the corresponding symbol can be extracted from the obfuscated format at runtime.
• The obfuscated format is actually a carrier of the complete "symbol table", which used to be PDB/DWARF.

Tool for restoring original DebugInfo from obfuscated format

Note

LiteLDev has not yet released bedrock_runtime_data/magicblob for the Linux server.

They are dethunk, dumpsym, askrva and makepdb (todo). Each tool is in a directory with the same name as it, and also has a README to help you use it.
In short, the PDB is generated by the following steps:

• Preprocess the header files published by LiteLDev by dethunk.
• Compile the header file and load the dumpsym plugin in the compilation parameters.

xmake f -c -p windows -a x64 -m release --sdk=/opt/msvc --cxflags=-fplugin=/path/to/libdumpsym.so --toolchain=clang
xmake -v

• Find the generated symbols file

{HEADER_PROJECT_DIR}/build/.objs/bdsheader/windows/x64/release/test/__cpp_main.cpp.cpp.symbols

• Generate symbol table using askrva

./askrva __cpp_main.cpp.cpp.symbols --output succeed.json --output-failed failed.txt --output-format=fakepdb

• This will generate a Json file that can be recognized by FakePDB. Refer to FakePDB's README to import it to IDB.

TODOs

• Automatically build PDB on CI.
• Tap into more available symbols.
• Fully open source HeaderGen.
• Standalone makepdb/makedwarf, no longer requires fakepdb.

Be with us

Our vision is to build an open and inclusive Minecraft: Bedrock Edition ecosystem.

• https://t.me/bdsplugin

LICENSE

All tools are open source under the MIT license.