[roll third_party/pigweed] pw_system: Make I/O a facade

Makes pw_system's io library a facade to allow targets to use things
other than pw_sys_io as their transport.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/75940

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 2c042f9c0098c30..66c509979444b2d
Roller-URL: https://ci.chromium.org/b/8825848918453761537
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8825848918453761537
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: If1a7b542c9c5a913188a50c2ffd56decfa4bbb6b
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/76900
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
1 file changed
tree: 3977a356a54c7cdf992bf92f243ccaebc10cab29
  1. applications/
  2. build_overrides/
  3. pw_board_led/
  4. pw_board_led_arduino/
  5. pw_board_led_host/
  6. pw_board_led_stm32cube/
  7. pw_board_led_stm32f429i_disc1/
  8. pw_spin_delay/
  9. pw_spin_delay_arduino/
  10. pw_spin_delay_host/
  11. pw_spin_delay_stm32cube/
  12. pw_spin_delay_stm32f429i_disc1/
  13. targets/
  14. third_party/
  15. tools/
  16. .gitattributes
  17. .gitignore
  18. .gitmodules
  19. .gn
  20. activate.bat
  21. banner.txt
  22. bootstrap.bat
  23. bootstrap.sh
  24. BUILD.gn
  25. BUILDCONFIG.gn
  26. env_setup.json
  27. navbar.md
  28. OWNERS
  29. PW_PLUGINS
  30. README.md
README.md

Pigweed Experimental

This repository contains experimental pigweed modules.

Repository setup

Clone this repo with --recursive to get all required submodules.

git clone --recursive https://pigweed.googlesource.com/pigweed/experimental

This will pull the Pigweed source repository into third_party/pigweed. If you already cloned but forgot to --recursive run git submodule update --init to pull all submodules.