Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/
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DuoYuWang 82ab33aed6 arch/arm/src/stm32{h7,f7,l4}: add 4-bit wide bus support for MMC/eMMC cards
The STM32H7, STM32F7, STM32L4 and common STM32 SDIO/SDMMC drivers failed
to program the WIDBUS bits when switching MMC/eMMC cards to 4-bit mode,
and the MMC transfer clock presets were hardwired to 1-bit bus width.

Add CLOCK_MMC_TRANSFER_4BIT to the common SDIO clock enum, add 4-bit
MMC clock presets, and update stm32_widebus() to use modifyreg32/
sdmmc_modifyreg32 to set the host controller bus width.

Signed-off-by: DuoYuWang <thirteenking.wang@gmail.com>
2026-07-21 08:51:38 -03:00
.github ci/testing: Free disk space before pulling the CI Docker image 2026-07-18 14:37:31 +02:00
arch arch/arm/src/stm32{h7,f7,l4}: add 4-bit wide bus support for MMC/eMMC cards 2026-07-21 08:51:38 -03:00
audio drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
binfmt elf:use elf symbol to parse attribute 2026-07-15 12:24:44 -03:00
boards arch/mips/jz4780: Add support for L2 cache operations 2026-07-21 16:40:08 +08:00
cmake cmake: Sanitize NAME for _main symbol generation 2026-07-17 13:04:26 -03:00
crypto crypto: add CRYPTO_AES_CTR_SSH variant (128-bit big-endian counter) 2026-07-16 15:42:10 +08:00
Documentation boards/linum-stm32h753bi: add curl config and document the curl command 2026-07-21 14:36:23 +08:00
drivers drivers/spi/ice40: fix operator precedence in final clock cycle count 2026-07-20 17:05:01 +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 2026-07-20 10:02:21 +02:00
graphics drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +08:00
include arch/arm/src/stm32{h7,f7,l4}: add 4-bit wide bus support for MMC/eMMC cards 2026-07-21 08:51:38 -03:00
libs spawn: allow zero stacksize/priority to use binary loader defaults 2026-07-15 12:24:44 -03:00
mm arch/mips: Add basic support for MIPS Creator CI20 board 2026-07-15 08:02:55 -03:00
net fix(net/igmp): restore General Query handling broken by pointer compare 2026-07-15 08:46:23 +02:00
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/backtrace: fix cross-CPU buffer access under addrenv 2026-07-20 21:01:28 -03:00
syscall syscall: fcntl param3 type to uintptr_t 2026-04-27 12:01:55 -03:00
tools arch/arm/rtl8721dx: add shared Ameba GPIO driver. 2026-07-21 08:34:05 +02:00
video video: fix EDID standard timing decode 2026-07-17 15:00:50 -03:00
wireless drivers/: Multiple Drivers Are Registered With World Writable - Part 2 2026-07-15 15:27:28 +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 risc-v/gd32vw55x: add GigaDevice GD32VW553 port (Wi-Fi 6) 2026-07-16 10:03:16 -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/nuttx_toolchain.cmake: track preprocessed include deps 2026-06-04 17:22:43 +08:00
CONTRIBUTING.md contributing: Add requirement for 'Assisted-by' commit field 2026-07-12 09:42:28 +08:00
INVIOLABLES.md
Kconfig sched/misc/assert: Add CONFIG_SCHED_DUMP_TASKS and CONFIG_SCHED_DUMP_STACK 2026-06-09 08:04:54 -04:00
LICENSE libs/libdsp: Add Matrix operations 2026-07-11 14:55:59 -03:00
Makefile !boards: enforce secure ROMFS passwd and TEA key setup 2026-07-09 22:41:11 +08:00
NOTICE Remove the double blank line from source files 2022-02-20 20:10:14 +01:00
README.md ci/testing: Add MemBrowse Integration 2026-06-18 12:07:41 -03:00
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.