572b7a0b55
Some host controllers must be told about the hubs in a topology, not only about the device at the end of it. xHCI is one: a hub's slot context carries a hub flag, its downstream port count and the think time of its transaction translator, and the controller routes to anything behind that hub using them. The hub class driver already reads both values from the hub descriptor and keeps them privately. Publish them on the hub's own hub port, beside the speed and function address that already describe the device attached there. A driver setting up a device behind a hub finds them on that device's parent. They are written before the hub activates any downstream port, so they are in place before there is anything behind it, and a port with no hub reports zero ports because the hub class clears each child before use. Nothing is required to read them. Fields rather than a driver method: a method would need a null check at the call site and would define an order it must be called in. Both are inside CONFIG_USBHOST_HUB, as struct usbhost_hubport_s's parent pointer already is. Multi-TT is not included; it comes from the hub's interface protocol rather than its descriptor, and driving a multi-TT hub as single-TT costs bandwidth behind it but is correct. Assisted-by: Claude:claude-opus-5 Signed-off-by: Justin Hammond <justin@dynam.ac> |
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| binfmt | ||
| boards | ||
| cmake | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| dummy | ||
| fs | ||
| graphics | ||
| include | ||
| libs | ||
| mm | ||
| net | ||
| openamp | ||
| pass1 | ||
| sched | ||
| syscall | ||
| tools | ||
| video | ||
| wireless | ||
| .asf.yaml | ||
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| .editorconfig | ||
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| .mcp.json | ||
| .pre-commit-config.yaml | ||
| .yamllint | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| INVIOLABLES.md | ||
| Kconfig | ||
| LICENSE | ||
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| 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.