Start build target config files

This change defines the build target system used by Pigweed, where the
build is configured using per-target globals imported from a target .gni
file. A single build arg specifying the path to the target file replaces
the previous args.

A default build variables file is provided in the Pigweed root. This
file defines and documents all of the build variables used by Pigweed.

A top-level targets directory is added to define the targets used by
Pigweed developers. Currently, only a "host" target is added, which
configures the build for a development system based on the host OS.

Change-Id: Ie62b8d41e5789bfe7fffe20462160142c79076c4
7 files changed
tree: 1b674ea88503143c59c98dd0f12d6a0012a487f5
  1. pw_build/
  2. pw_docgen/
  3. pw_preprocessor/
  4. pw_span/
  5. pw_status/
  6. pw_toolchain/
  7. pw_unit_test/
  8. targets/
  9. .clang-format
  10. .gitignore
  11. .gn
  12. AUTHORS
  13. BUILD.gn
  14. BUILDCONFIG.gn
  15. CONTRIBUTING.md
  16. LICENSE
  17. modules.gni
  18. pw_vars_default.gni
  19. README.md
README.md

Pigweed embedded oriented software libraries

Pigweed is a collection of embedded-focused libraries, which we call "modules". These modules are designed for small-footprint MMU-less microcontrollers like the ST Micro STM32L452 or the Nordic NRF82832. The modules are designed to facilitate easy integration into existing codebases.

Pigweed is in the early stages of development.