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>
Modify ARM64 architecture configuration to disable fork support in protected
build mode (BUILD_PROTECTED). Update ARCH_HAVE_FORK condition from
"!BUILD_KERNEL" to "!BUILD_KERNEL && !BUILD_PROTECTED", ensuring fork is
only available in flat/monolithic builds, not in protected kernel builds.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
It's better to save one argument by returning pid directly.
This change also follow the convention of task_create.
BTW, it is reasonable to adjust the function prototype a
little bit from both implementation and consistency since
task_spawn is NuttX specific API.
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
