Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/
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dechao_gong 2b65c77adb arch/arm/rtl8721dx: add shared Ameba RTC driver
Expose the Ameba on-chip RTC as a NuttX date/time RTC at /dev/rtc0
(rdtime/settime) with a single one-shot alarm (setalarm/rdalarm/
cancelalarm/setrelative) that fires the RTC interrupt and the upper-half
callback.  The same hardware also backs the arch date/time RTC hooks
(up_rtc_initialize/getdatetime/settime, g_rtc_enabled) so the NuttX
system time is seeded from it.

The driver sits on the SDK fwlib RTC API (mirrored structures + local
externs, no vendor headers pulled into the NuttX include world).  The
fwlib RTC API lives in the RAM source ameba_rtc.c, so it is added to the
board fwlib build under CONFIG_AMEBA_RTC.  The hardware keeps a year plus
a day-of-year (no month/day register); the driver bridges that to the
NuttX month/day calendar with the libc UTC routines (timegm/gmtime_r),
which is exact and reversible.

The only per-chip fact -- the RTC interrupt vector -- lives in the
per-chip ameba_rtc_chip.h; the shared driver is never edited for a new
Ameba chip.  A configs/rtc profile (examples/alarm) is added for
verification.

Signed-off-by: dechao_gong <dechao_gong@realsil.com.cn>
Assisted-by: Claude <noreply@anthropic.com>
2026-08-27 01:09:15 +08:00
.github build(deps): bump docker/setup-buildx-action from 4.2.0 to 4.3.0 2026-08-24 15:30:16 +08:00
arch arch/arm/rtl8721dx: add shared Ameba RTC driver 2026-08-27 01:09:15 +08:00
audio audio: limit the buffer count guard to shared ring requests 2026-08-05 07:58:53 +02:00
binfmt sched: add supplementary group IDs (setgroups/getgroups/initgroups) 2026-08-12 16:06:03 -03:00
boards arch/arm/rtl8721dx: add shared Ameba RTC driver 2026-08-27 01:09:15 +08:00
cmake sched,fs,docs: support setuid sudo helper 2026-08-18 15:57:52 +08:00
crypto tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00
Documentation arch/arm/rtl8721dx: add shared Ameba RTC driver 2026-08-27 01:09:15 +08:00
drivers drivers/serial: correct the USART9 console label 2026-08-27 01:01:51 +08:00
dummy build: add initial cmake build system 2023-07-08 13:50:48 +08:00
fs nuttx/atomic: replace atomic_fetch_xxx with atomic_xxx just like zephyr 2026-08-24 13:20:45 +08:00
graphics graphics/nxterm: consume SGR escape sequences 2026-08-23 10:46:02 +08:00
include include/nuttx: Add link-time iterable sections infrastructure 2026-08-27 01:04:05 +08:00
libs arch/tricore: drop illd dependence for atomic 2026-08-25 10:07:25 +08:00
mm cmake: Use NUTTX(_DIR/_BIN_DIR) instead CMAKE(_SRC_DIR/_BIN_DIR) 2026-08-09 11:13:08 -03:00
net net/local: fix SCM_RIGHTS pointer and memory corruption 2026-08-21 02:19:10 +08:00
openamp cmake: Use NUTTX(_DIR/_BIN_DIR) instead CMAKE(_SRC_DIR/_BIN_DIR) 2026-08-09 11:13:08 -03:00
pass1 tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00
sched nuttx/atomic: replace atomic_fetch_xxx with atomic_xxx just like zephyr 2026-08-24 13:20:45 +08:00
syscall sched: add supplementary group IDs (setgroups/getgroups/initgroups) 2026-08-12 16:06:03 -03:00
tools include/nuttx: Add link-time iterable sections infrastructure 2026-08-27 01:04:05 +08:00
video tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00
wireless nuttx/atomic: replace atomic_fetch_xxx with atomic_xxx just like zephyr 2026-08-24 13:20:45 +08:00
.asf.yaml github: master branch protection tune. 2025-05-07 18:37:13 -05:00
.codespell-ignore-lines arch/arm: Reserve r10 via ARCHCFLAGS and hoist the PIC module flags. 2026-07-24 23:09:08 +08:00
.codespellrc arch/arm/rp23xx: Add hardware TRNG driver for /dev/random. 2026-07-25 15:06:56 +08:00
.editorconfig .editorconfig: fix character encoding property specification 2025-11-28 19:12:13 +08:00
.gitignore boards/risc-v/eic7700x: Adopt the common board layout. 2026-08-19 01:40:57 +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 Jorge Guzman 2026-08-25 08:43:13 -04:00
CMakeLists.txt include/nuttx: Add link-time iterable sections infrastructure 2026-08-27 01:04:05 +08:00
CONTRIBUTING.md contributing: Add requirement for 'Assisted-by' commit field 2026-07-12 09:42:28 +08:00
INVIOLABLES.md
Kconfig include/nuttx: Add link-time iterable sections infrastructure 2026-08-27 01:04:05 +08:00
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.