Clone this repo:
  1. 103d628 Merge changes I93476e3e,I9ebca2f2 by Steven Moreland · 2 days ago master
  2. cbd6cc9 hidl2aidl: emit @VintfStability before structs by Steven Moreland · 3 days ago
  3. 69ec771 hidl2aidl_test builds backends. by Steven Moreland · 3 days ago
  4. e7ea091 Move IBase transaction codes back to libhwbinder. by Steven Moreland · 11 days ago
  5. 54186d1 Add android namespace to hidl error for safe unions by Devin Moore · 2 weeks ago


Full documentation can be found here:

hidl-gen is a compiler for the HIDL (HAL Interface Design Language) which generates C++ and Java endpoints for RPC mechanisms. The main userspace libraries which this compiler uses can be found at system/libhidl.

1. Build

m hidl-gen

2. Run

Note that options for hidl-gen expected to be invoked by the build system are marked with ‘internal’ in the help menu.

hidl-gen -h

hidl-gen -o output -L c++-impl -r android.hardware:hardware/interfaces -r android.hidl:system/libhidl/transport android.hardware.nfc@1.0

Some defaults for package roots are also provided

hidl-gen -o output -L c++-impl android.hardware.nfc@1.0
hidl-gen -o output -L vts android.hardware.nfc@1.0
hidl-gen -L hash android.hardware.nfc@1.0

Example command for vendor project

hidl-gen -L c++-impl -r

See and for examples of how to generate HIDL makefiles (using the -Landroidbp option).

NOTE: When using the -Landroidbp option, you can force generated modules to be installed in /system_ext rather than other parition by putting a marker file .hidl_for_system_ext alongside *.hal files.


This is a helper tool to convert C headers to valid .hal files.

m c2hal && c2hal -h