[syscalls][serial] Support partial disabling of serial syscalls

Extend kernel.enable-serial-syscalls to also support an "output-only"
setting, in addition to the previous fully-enabled and fully-disabled
values.

This supports enabling serial write (from the target's perspective), but
disabling read.

Extending the previous command line value allows for a soft transition
for configurations where =true and =false are already in use.

Test: new test in disable_syscalls_test
Bug: 44751
Change-Id: Ie3f937ee1e8d562258ee73dc442a44dd2039bfc6
6 files changed
tree: 72631df1631216178e38cf899ce67a8898588bb8
  1. boards/
  2. build/
  3. bundles/
  4. docs/
  5. examples/
  6. garnet/
  7. products/
  8. scripts/
  9. sdk/
  10. src/
  11. third_party/
  12. tools/
  13. zircon/
  14. .clang-format
  15. .clang-tidy
  16. .dir-locals.el
  17. .gitattributes
  18. .gitignore
  19. .gn
  20. .style.yapf
  21. AUTHORS
  22. BUILD.gn
  23. CODE_OF_CONDUCT.md
  24. CONTRIBUTING.md
  25. LICENSE
  26. OWNERS
  27. PATENTS
  28. README.md
  29. rustfmt.toml
README.md

Fuchsia

Pink + Purple == Fuchsia (a new operating system)

What is Fuchsia?

Fuchsia is a modular, capability-based operating system. Fuchsia runs on modern 64-bit Intel and ARM processors.

Fuchsia is an open source project with a code of conduct that we expect everyone who interacts with the project to respect.

How can I build and run Fuchsia?

See Getting Started.

Where can I learn more about Fuchsia?

See fuchsia.dev.