What a controller is told about a device before it will accept it. A DWC3 core validates these where QEMU's controller does not. - HCCPARAMS1 says whether context structures are 32 or 64 bytes, and the wider form was refused outright with -EIO; the EIC7700X reports 0x0220fe45 on both of its controllers, so this driver could not have driven either. A wide context is the same fields with reserved space after them, so only the stride changes. Read it at start up and use it wherever a context array is walked. - Contexts must be 64 byte aligned, since every device context base address array entry points at one, and the output context came from kmm_zalloc(). - The slot context never carried the device speed, which has no valid zero, so a validating controller answers Address Device with a parameter error. The speed was already implied by the endpoint context's maximum packet size. The numbering is xHCI's own, hence the mapping. - The output device context was cleared and never flushed. That context is the controller's to write, so what stays behind is a dirty line of zeros written back over the slot state, and the next command against the slot is refused with a context state error. Enumeration reached SET_ADDRESS and stopped. - A buffer copied through an aligned stand-in was copied back using buflen, which control transfers deliberately leave zero, so a descriptor read copied nothing back and the caller was handed whatever its buffer held before. Keep the requested length separately, and maintain the cache over the whole stand-in rather than the part in use. - A buffer the controller cannot reach is now copied through a stand-in rather than refused. -EFAULT works for a caller with somewhere better to put the data, and fails outright for one without: reading a block device directly from a user program returned an error where the transfer could have gone through a stand-in. Assisted-by: Claude:claude-opus-5 Signed-off-by: Justin Hammond <justin@dynam.ac> |
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| .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.