53c27e155b
usbdev_register() calls CLASS_BIND, which ends with DEV_CONNECT (composite_bind/cdcacm_bind) and sets SIE_CTRL.PULLUP_EN, and then performs a wholesale putreg32 of SIE_CTRL to set EP0_INT_1BUF -- clobbering the pull-up microseconds after it was asserted. Enumeration only ever succeeded because the host happened to latch the microsecond pull-up blip and issued a bus reset, whose handler (CLASS_DISCONNECT -> DEV_CONNECT) re-arms the pull-up. A warm host port catches the blip; a cold-plugged port is still in attach debounce, misses it, and never resets -- PULLUP_EN stays 0 forever and the device is totally silent on the bus while NuttX runs normally underneath. This presented as an intermittent, image-dependent "cold boot brick" (boot timing shifts the blip in or out of the host's blind window). Fix: set EP0_INT_1BUF with setbits_reg32 so PULLUP_EN survives. Validated on RP2350 silicon (Raspberry Pi Pico 2 W): an image that failed 0/10 cold plugs enumerated 10/10 with the fix; a second board that had never enumerated at all was recovered by it. The rp2040 driver has the identical code and receives the identical fix (build-tested; the RP2350 validation exercised the shared logic). Fixes apache/nuttx#19434 Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Signed-off-by: Ricard Rosson <ricard@groundbits.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.