ecacc7bc7c
Some checks are pending
Build Documentation / build-html (push) Waiting to run
MemBrowse Memory Report / changes-filter (push) Waiting to run
MemBrowse Memory Report / load-targets (push) Waiting to run
MemBrowse Memory Report / identical (push) Blocked by required conditions
MemBrowse Memory Report / analyze (push) Blocked by required conditions
The audio subsystem page listed the source files and the configuration options, but nothing about the interface the upper half presents to applications. PR #18348 added a device state machine, a second buffer allocation mode, poll and mmap support and several new ioctls, none of which were described anywhere, so the only way to learn the expected call sequence was to read audio/audio.c. Document what the upper half now guarantees: - the device state machine, and the fact that AUDIOIOC_START is rejected until AUDIOIOC_CONFIGURE has moved the device out of AUDIO_STATE_OPEN; - the normal open/configure/allocate/enqueue/start sequence; - the two AUDIOIOC_ALLOCBUFFER modes selected by u.pbuffer, who owns the buffers in each, and that a shared ring request may return zero when the ring is already populated; - that AUDIOIOC_GETBUFFERINFO also establishes the shared ring depth, so a lower half which does not implement it disables that mode; - the poll event semantics and how mmap() selects between a ring buffer and the device status by requested length; - all ioctls handled by the upper half, grouped by purpose; - how per-open state is aggregated into the device state when several applications share one device. No functional change. Signed-off-by: fangyibo <fangyibo@xiaomi.com> |
||
|---|---|---|
| .github | ||
| arch | ||
| audio | ||
| binfmt | ||
| boards | ||
| cmake | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| dummy | ||
| fs | ||
| graphics | ||
| include | ||
| libs | ||
| mm | ||
| net | ||
| openamp | ||
| pass1 | ||
| sched | ||
| syscall | ||
| tools | ||
| video | ||
| wireless | ||
| .asf.yaml | ||
| .codespell-ignore-lines | ||
| .codespellrc | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmessage | ||
| .pre-commit-config.yaml | ||
| .yamllint | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| INVIOLABLES.md | ||
| Kconfig | ||
| LICENSE | ||
| Makefile | ||
| NOTICE | ||
| README.md | ||
| ReleaseNotes | ||
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.