e6696d5d27
imxrt_transmit() handed out the lowest free TX mailbox. FlexCAN breaks an arbitration tie between mailboxes holding equal CAN IDs by taking the lowest mailbox number, so refilling a just-drained low mailbox while older frames are still pending in higher ones puts the newer frame on the wire first. imxrt_txdone_work() re-polls after each individual TX completion, which is exactly the condition that triggers it. Every frame of a multi-frame transport transfer carries the same CAN ID, so this reorders transfers. On a DroneCAN bus the receiver sees a broken toggle bit and discards the transfer: measured on the wire, a 6-frame message from an i.MX RT1176 failed 82% of the time, while a node on the same bus running a different controller was flawless over the same capture. Hand out a mailbox above every pending one instead, and wrap back to the bottom only once the ring has drained. Ordering then holds for any transfer length; the cost is that the ring stalls at a wrap rather than refilling immediately. Assisted-by: Claude:claude-opus-5 Signed-off-by: Jacob Dahl <dahl.jakejacob@gmail.com> |
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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.