Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/
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Tiago Medicci Serrano b28d60947a boards/xtensa/esp32/esp32-devkitc: Fix psram_usrheap defconfig
When both CONFIG_ESP32_SPIRAM and  CONFIG_ESP32_SPIRAM_USER_HEAP
are selected, the device must not select CONFIG_NSH_ARCHINIT.
Instead, CONFIG_BOARD_LATE_INITIALIZE must be selected. This is
necessary because the SPI flash initialization disables the cache,
and only internal memory is then accessible. So, if the  SPI flash
initialization is performed by the entry task (nsh_main, a regular
task), it would use the user heap to allocate memory, which would
cause a system crash when the cache is disabled. On the other hand,
by selecting CONFIG_BOARD_LATE_INITIALIZE, a kernel thread is
dedicated to perform the initialization, and the cache can be
safely disabled.

Signed-off-by: Tiago Medicci Serrano <tiago.medicci@espressif.com>
2026-04-14 09:21:17 +02:00
.github workflows/build.yml: job MSVC fix Filename too long 2026-04-13 23:55:10 +08:00
arch arch/xtensa/esp32: Fix ROM strdup heap issue in USER_HEAP mode 2026-04-14 09:21:17 +02:00
audio include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
binfmt include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
boards boards/xtensa/esp32/esp32-devkitc: Fix psram_usrheap defconfig 2026-04-14 09:21:17 +02:00
cmake cmake: add -D__NuttX__ to preprocessor 2026-04-10 12:22:24 -03:00
crypto include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
Documentation arch/nrf52|nrf53: add qencoder support 2026-04-12 19:41:52 -04:00
drivers video/gc0308: implement V4L2 horizontal flip control 2026-04-10 10:47:07 +02:00
dummy
fs fs/fat: fix incorrect representation of SFN files created on Linux 2026-04-14 09:51:20 +08:00
graphics include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
include nuttx/nx: compilation error occurs 2026-04-14 13:35:26 +08:00
libs include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
mm include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
net net/route: fix return value of net_writeroute_ipv6 2026-04-13 08:46:57 -03:00
openamp openamp: Fix Make style 2026-03-23 18:16:46 -04:00
pass1 Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
sched include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
syscall Makefile: Remove make depend files by make distclean 2026-02-16 16:27:57 +01:00
tools tools/ci: Added esptool for Windows Native 2026-04-13 23:55:10 +08:00
video include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
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 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 cmake: Enhance .config handling and comparison logic 2026-02-26 09:46:02 -03:00
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 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 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.