Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/
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Marco Casaroli b903062b75 tools/mkallsyms.py: let the dependency error actually reach the user
mkallsyms.py prints "Please execute the following command to install
dependencies: pip install pyelftools cxxfilt" and then calls
os._exit(errno.EINVAL).  os._exit() terminates without flushing stdio, so
when stdout is a pipe -- which it always is under make -- the message sits in
the buffer and is discarded.  What the developer sees is:

  make[1]: *** [Makefile:65: nuttx] Error 22

with no indication of the cause anywhere in the build output.  Error 22 is
just errno.EINVAL leaking out as an exit status.  The same applies to
usage(), which exits ENOENT the same way.

Use sys.exit() in both places, which raises SystemExit and lets the
interpreter flush on the way out.  Nothing else changes:  the exit statuses
are the same, and os is no longer referenced, so the import goes too.

Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>

Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-04 00:36:00 +08:00
.github !arch/stm32: move stm32l1 and finalize the directory split 2026-07-03 10:27:27 +08:00
arch arch/arm: carry CONTROL over to the fork child on Cortex-M 2026-08-04 00:35:32 +08:00
audio drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-08-03 17:23:22 +08:00
binfmt fs/binfmt: Enforce POSIX execute permissions prior to binary load 2026-06-17 17:11:07 +08:00
boards boards/mps2-an521: Correct the swapped UART0 TX and RX interrupts. 2026-08-03 23:17:11 +08:00
cmake cmake: Sanitize NAME for _main symbol generation 2026-08-03 20:59:22 +08:00
crypto drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-08-03 17:23:22 +08:00
Documentation docs/raspberrypi-4b: Documentation about the SD card updated 2026-08-03 20:57:47 +08:00
drivers drivers/video: zero message on MIPI DSI driver 2026-08-03 23:16:13 +08:00
dummy build: add initial cmake build system 2023-07-08 13:50:48 +08:00
fs drivers/eeprom: I2C EEPROM Read/Write Kernel Operations Cause a Device Crash 2026-08-03 21:00:39 +08:00
graphics drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-08-03 17:23:22 +08:00
include lib/math32: Avoid __uint128_t casts for LDC ImportC 2026-08-03 22:20:43 +08:00
libs libs/libbuiltin/compiler-rt: skip unsupported Arm VFP builtins asm 2026-08-03 23:18:05 +08:00
mm mm/gran: reject pools with too many granules 2026-07-03 10:32:15 +08:00
net net/tcp: don't accept a reset connection as connected (fixes send hang) 2026-08-04 00:35:39 +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 sched/sched_critmonitor: remove duplicate preemption start block 2026-08-04 00:35:18 +08:00
syscall syscall: fcntl param3 type to uintptr_t 2026-04-27 12:01:55 -03:00
tools tools/mkallsyms.py: let the dependency error actually reach the user 2026-08-04 00:36:00 +08:00
video video: fix EDID standard timing decode 2026-08-03 20:59:41 +08:00
wireless drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-08-03 17:23:22 +08:00
.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 feat: add a GitHub action to lint the YAML files 2020-12-15 09:52:04 -06:00
AUTHORS AUTHORS: add Eren Terzioglu 2026-05-20 15:17:00 +08:00
CMakeLists.txt cmake: Do not link an executable to detect the compiler. 2026-08-03 22:21:10 +08:00
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 sched/misc/assert: Add CONFIG_SCHED_DUMP_TASKS and CONFIG_SCHED_DUMP_STACK 2026-07-04 13:29:32 -04:00
LICENSE !arch/stm32: move stm32l1 and finalize the directory split 2026-07-03 10:27:27 +08:00
Makefile !boards: enforce secure ROMFS passwd and TEA key setup 2026-07-06 12:04:07 -03:00
NOTICE Remove the double blank line from source files 2022-02-20 20:10:14 +01:00
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.