Marco Casaroli
aae62ceaae
Documentation/guides/fork_vfork_migration.rst is new. It says what changed and why, gives the two primitives as a table, states plainly what breaks, and answers "which replacement do I want?" from the reader's own reason for having called fork() -- posix_spawn() or vfork() to run a program, pthread_create() for a second flow of control that shares memory, fork() itself for an independent copy. It also documents the two configuration symbols, what an architecture has to implement to gain real fork(), and the one visible consequence of moving the vfork() suspension into the kernel: a waitpid() after a child that _exit()s can only report status where CONFIG_SCHED_CHILD_STATUS is enabled. reference/user/01_task_control.rst gains an entry for fork() and rewrites the one for vfork(), which described NuttX's limitations rather than the interface's contract. standards/posix.rst moves fork() from "No" to "Cond." and vfork() from "Yes" to "Cond.", both being conditional on the configuration now. implementation/memory_configurations.rst no longer lists fork() as unimplementable in the presence of address environments, which was the whole point of that section's wish list. Three long-standing typos in that file are corrected while touching it, since codespell checks the whole of any file a patch modifies. BREAKING CHANGE: this commit carries no code; it is the migration guide for the fork() withdrawal in the commit before it, and is marked so that every commit in the series carries the marker CONTRIBUTING.md 1.13 requires. The quick fixes are in Documentation/guides/fork_vfork_migration.rst. Assisted-by: Claude Code:claude-opus-5 Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
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.