Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/
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Chengdong Wang fa534b75b7 arch/riscv: Add CONFIG_ARCH_RV_ISA_ZICSR_ZIFENCEI for fence.i
The fence.i instruction is only available when the Zifencei extension
(CONFIG_ARCH_RV_ISA_ZICSR_ZIFENCEI) is supported by the hardware.

This commit adds a macro wrapper around fence.i usages to prevent
compilation errors on toolchains or targets where the Zifencei
extension is absent.

Signed-off-by: Chengdong Wang <wangcd91@gmail.com>
2026-07-04 02:00:04 +08:00
.github !arch/stm32: move stm32l1 and finalize the directory split 2026-07-03 10:27:27 +08:00
arch arch/riscv: Add CONFIG_ARCH_RV_ISA_ZICSR_ZIFENCEI for fence.i 2026-07-04 02:00:04 +08:00
audio include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
binfmt fs/binfmt: Enforce POSIX execute permissions prior to binary load 2026-06-17 17:11:07 +08:00
boards boards/sim: Configuration for NXDoom on simulator 2026-07-04 01:59:40 +08:00
cmake boards/arm/qemu: Fix KASAN global sections placement in linker script 2026-07-03 10:32:00 +08:00
crypto !nuttx: drop redundant casts on tv_sec/tv_nsec and fix printf formats 2026-05-19 16:21:28 +08:00
Documentation docs/sim: Include documentation about NXDoom configuration 2026-07-04 01:59:40 +08:00
drivers stdlib/rand: replace weak LCG with xorshift32 PRNG 2026-07-04 01:59:35 +08:00
dummy
fs !include/fcntl.h: align open flags with Linux values 2026-07-03 10:33:47 +08:00
graphics !include/fcntl.h: align open flags with Linux values 2026-07-03 10:33:47 +08:00
include !include/fcntl.h: align open flags with Linux values 2026-07-03 10:33:47 +08:00
libs stdlib/rand: replace weak LCG with xorshift32 PRNG 2026-07-04 01:59:35 +08:00
mm mm/gran: reject pools with too many granules 2026-07-03 10:32:15 +08:00
net !include/fcntl.h: align open flags with Linux values 2026-07-03 10:33:47 +08:00
openamp openamp: fix CMake dcache option 2026-05-10 15:03:24 +02:00
pass1 Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
sched !include/fcntl.h: align open flags with Linux values 2026-07-03 10:33:47 +08:00
syscall syscall: fcntl param3 type to uintptr_t 2026-04-27 12:01:55 -03:00
tools tools/nxstyle.c: Add symbols for drivers/crypto/pnt/pnt_se05x_api.c 2026-07-03 10:31:02 +08:00
video video: ensure video library is non-empty 2026-05-08 19:51:39 +08:00
wireless include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
.asf.yaml github: master branch protection tune. 2025-05-07 18:37:13 -05:00
.codespell-ignore-lines !boards: Remove NSH_ARCHINIT and board_app_initialize 2026-05-02 18:36:46 +08:00
.codespellrc arch/sim: replace macOS C++ constructor runtime hack with post-link patch 2026-05-19 07:08:55 -03:00
.editorconfig .editorconfig: fix character encoding property specification 2025-11-28 19:12:13 +08:00
.gitignore git: Specify multiple build directories in .gitignore. 2026-05-20 03:06:58 +08:00
.gitmessage docs/contributing: Add a commit message template 2025-06-03 17:33:24 +08:00
.pre-commit-config.yaml pre-commit: enable codespell checks 2025-05-05 12:34:39 +08:00
.yamllint
AUTHORS AUTHORS: add Eren Terzioglu 2026-05-20 15:17:00 +08:00
CMakeLists.txt tools/rust: Fix aarch64 NuttX Rust target specs 2026-05-29 10:25:10 +02:00
CONTRIBUTING.md docs: Fix typos, formatting, and numbering in README.md and CONTRIBUTING.md. 2026-03-23 12:05:24 +01:00
INVIOLABLES.md
Kconfig tools/stackusage.py: use toolchain binaries instead of Python libraries 2026-03-17 11:26:44 -03:00
LICENSE !arch/stm32: move stm32l1 and finalize the directory split 2026-07-03 10:27:27 +08:00
Makefile tools: migrate to SPDX identifier 2024-09-10 23:11:11 +08:00
NOTICE
README.md docs: Fix typos, formatting, and numbering in README.md and CONTRIBUTING.md. 2026-03-23 12:05:24 +01:00
ReleaseNotes Documentation: move ReleaseNotes 2023-09-26 20:41:00 +08:00

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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.