1dfa028808
O_DIRECTORY, O_NOFOLLOW, O_NOATIME, O_CLOEXEC, __O_SYNC, O_PATH and __O_TMPFILE are defined as shifts by 16 to 22 bits. Where int is 16 bits (AVR, for example), these shifts exceed the width of the type: GCC evaluates them to 0, and the -Wshift-count-overflow warning is not shown because include/ is a system include directory. The oflags argument of open() is an int, so it could not carry those bits anyway. As a result, on arch with int equal 16-bit opendir() opens directories without O_DIRECTORY, so opening a mount point such as /proc fails with ENOENT, and O_CLOEXEC and O_NOFOLLOW have no effect. When UINT_MAX is 0xffff, use the unused bits 2 to 4 for O_DIRECTORY, O_CLOEXEC and O_NOFOLLOW, define O_NOATIME and __O_SYNC as 0 (O_SYNC falls back to O_DSYNC), and leave O_PATH and O_TMPFILE undefined, so that code which needs them fails to build instead of silently opening with the wrong flags; nothing in the tree uses them. _O_MAXBIT becomes 15. On bigger systems (32-bit, 64-bit) keep the original bit shift. Signed-off-by: Alan Carvalho de Assis <acassis@gmail.com> Assisted-by: Claude Opus 5.5 (claude-opus-5-5) |
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| .github | ||
| arch | ||
| audio | ||
| binfmt | ||
| boards | ||
| cmake | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| dummy | ||
| fs | ||
| graphics | ||
| include | ||
| libs | ||
| mm | ||
| net | ||
| openamp | ||
| pass1 | ||
| sched | ||
| syscall | ||
| tools | ||
| video | ||
| wireless | ||
| .asf.yaml | ||
| .codespell-ignore-lines | ||
| .codespellrc | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmessage | ||
| .mcp.json | ||
| .pre-commit-config.yaml | ||
| .yamllint | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| INVIOLABLES.md | ||
| Kconfig | ||
| LICENSE | ||
| Makefile | ||
| NOTICE | ||
| README.md | ||
| ReleaseNotes | ||
Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).
For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.
Getting Started
First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.
Documentation
You can find the current NuttX documentation on the Documentation Page.
Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.
The old NuttX documentation is still available in the Apache wiki.
Supported Boards
NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.
Contributing
If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.
License
The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.