Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/
Find a file
Matteo Golin 2d768c294e arch/delays: Invalid default value for BOARD_LOOPSPERMSEC
Changes the default value for CONFIG_BOARD_LOOPSPERMSEC to -1, which is
invalid. All boards that forget to configure this value will encounter a
static assertion at compile time, enforcing that configurations
upstreamed to NuttX have calibrated values for correct delay timings.

Boards which implement ALARM_ARCH or TIMER_ARCH do not rely on the
busy-loop delay implementation and thus only have a run-time check to
ensure proper delay-timings (in the case where delays are used before
the alarm/timer driver is registered).

Some boards already in the NuttX upstream do not have calibrated values,
but there are no users who currently own the board to submit a
calibrated value for the configurations to use. In this scenario, the
value is temporarily set to 0 and a warning is displayed so that users
of these boards are informed of the calibration process.

Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
2026-02-25 15:00:03 -03:00
.github github/workflow: Fix the PR Labeling for Build System 2026-02-22 08:33:10 +08:00
arch arch/delays: Invalid default value for BOARD_LOOPSPERMSEC 2026-02-25 15:00:03 -03:00
audio Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
binfmt Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
boards boards/arm/a1x: CMake added QuickFeather board 2026-02-25 06:47:58 +08:00
cmake cmake(bugfix):change default compile obj extension to .o 2026-01-27 20:54:26 +08:00
crypto Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
Documentation boards/stm32h7: Add button support to nucleo-h743zi2 2026-02-21 08:50:54 +01:00
drivers arch/delays: Invalid default value for BOARD_LOOPSPERMSEC 2026-02-25 15:00:03 -03:00
dummy build: add initial cmake build system 2023-07-08 13:50:48 +08:00
fs Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
graphics Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
include serial/uart_rpmsg: add _raw version of driver 2026-02-23 09:19:57 -03:00
libs Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
mm mm:use mm_malloc inside of mm_memalign 2026-02-24 19:58:17 +08:00
net Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
openamp Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
pass1 Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
sched arch/delays: Invalid default value for BOARD_LOOPSPERMSEC 2026-02-25 15:00:03 -03:00
syscall Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
tools tools: fix make host_info flag parsing and config string escaping 2026-02-05 14:23:19 +01:00
video Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
wireless Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
.asf.yaml github: master branch protection tune. 2025-05-07 18:37:13 -05:00
.codespell-ignore-lines net/icmpv6: replace net_lock with conn_lock and conn_lock_dev 2025-12-29 09:42:18 +08:00
.codespellrc codespellrc: add ist to ignorelist 2025-10-14 17:42:01 +08:00
.editorconfig .editorconfig: fix character encoding property specification 2025-11-28 19:12:13 +08:00
.gitignore gitignore: add more vim swap files 2025-06-18 15:44:51 -04:00
.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 Donny Jiuzhu 2026-02-25 10:17:40 +01:00
CMakeLists.txt boards/arm/stm32: Fix CMake build for protected mode on stm32f4discovery 2026-02-02 13:24:34 +08:00
CONTRIBUTING.md doc: Contributing Guide updates. 2026-02-19 12:11:14 -05:00
INVIOLABLES.md
Kconfig Kconfig: Add ALLOW_CUSTOM_PERMISSIVE_COMPONENTS option 2026-01-20 02:15:19 +08:00
LICENSE style: fix spelling in code comments and strings 2025-05-23 10:48:41 +08:00
Makefile tools: migrate to SPDX identifier 2024-09-10 23:11:11 +08:00
NOTICE
README.md Gathering community recommendations 2023-10-28 13:55:56 +08:00
ReleaseNotes Documentation: move ReleaseNotes 2023-09-26 20:41:00 +08:00

POSIX Badge License Issues Tracking Badge Contributors GitHub Build Badge Documentation Badge

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.