This fixes two issues with the tick timer 1) Each tick was longer than the requested period. This is because setting the compare register was done by first reading the current time, and only after that setting the compare register. In addition, when handling the timer interrupts in arch_alarm.c / oneshot_callback, the current_tick is first read, all the tick handling is done and only after that the next tick is started. The whole tick processing time was added to the total tick time. 2) When the compare time is not aligned with tick period, and is drifting, eventually any call to ONESHOT_TICK_CURRENT would either return the current tick, or the next one, depending on the rounding of division by the cycle_per_tick. This again leads to oneshot_callback randomly handling two ticks at a time, which breaks all wdog based timers, causing them to randomly timeout too early. The issues are fixed as follows: Align the compare time register to be evenly divisible by cycle_per_tick. This will lead arm64_tick_current always to return the currently ongoing tick, fixing 2). Also calculating the next tick's start from the aligned current count will fix 1), as there is no time drift in the start cycle. Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae> |
||
|---|---|---|
| .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 | ||
| .gitignore | ||
| .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.