upac

upac is a small C++ utility/library for reading Unisoc/Spreadtrum .pac firmware packages.

It can:

• inspect PAC headers and file tables
• extract embedded files
• dump the embedded XML flash scheme
• expose reusable PAC parsing logic to other tools like uflash

Build

cmake -S . -B build
cmake --build build

The CLI binary is produced as:

./build/upac

Usage

./build/upac info firmware.pac
./build/upac list firmware.pac
./build/upac extract firmware.pac extracted/
./build/upac xml firmware.pac
./build/upac ops firmware.pac
./build/upac verify firmware.pac

Library

The reusable library target is upac_lib with alias upac::upac.

Other CMake projects in this source tree can consume it with:

add_subdirectory(../upac upac-build)
target_link_libraries(my_tool PRIVATE upac::upac)

Notes

• PAC metadata strings are UTF-16LE on disk and are converted to UTF-8 in memory.
• The reader caches decoded file metadata and XML config so repeated operations are faster.
• Extraction is streamed in chunks, so large images do not need to be fully loaded into memory first.