nuttx/Documentation/implementation
Marco Casaroli aae62ceaae !Documentation: Describe the fork()/vfork() split.
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>
2026-08-10 08:57:30 -03:00
..
bottomhalf_interrupt.rst docs/implementation: fix minor typos 2024-05-04 13:24:32 +08:00
cancellation_points.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
chip_h.rst !arch/stm32: move stm32l1 and finalize the directory split 2026-06-24 14:54:44 -03:00
context_switches.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
crc.rst Documentation: add CRC implementation details 2026-07-03 10:18:28 +08:00
critical_sections.rst style: Fix "the the" typo across the codebase. 2026-03-23 11:07:49 +01:00
device_drivers.rst style: Fix "the the" typo across the codebase. 2026-03-23 11:07:49 +01:00
device_nodes.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
disabling_interrupts.png Documentation: migrate "Effects of Disabling Interrupts or Pre-Emption on Response Latency" from wiki 2023-11-06 09:03:07 +08:00
disabling_preemption.png Documentation: migrate "Effects of Disabling Interrupts or Pre-Emption on Response Latency" from wiki 2023-11-06 09:03:07 +08:00
drivers_design.rst style: Fix "the the" typo across the codebase. 2026-03-23 11:07:49 +01:00
file_descriptors.rst !arch/stm32: move stm32l1 and finalize the directory split 2026-06-24 14:54:44 -03:00
file_permission.rst Documentation: describe FS permission interface and mount-crossing 2026-08-02 18:48:40 -03:00
hardfaults.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
index.rst Documentation: describe FS permission interface and mount-crossing 2026-08-02 18:48:40 -03:00
interrupt_controls.rst style: Fix "the the" typo across the codebase. 2026-03-23 11:07:49 +01:00
ioctl.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
kernel_modules_vs_shared_libraries.rst Documentation: Document dlopen() reference counting. 2026-08-04 11:12:49 -03:00
kernel_threads_vs_pthreads.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
make_build_system.rst style: Fix "the the" typo across the codebase. 2026-03-23 11:07:49 +01:00
memory_configurations.rst !Documentation: Describe the fork()/vfork() split. 2026-08-10 08:57:30 -03:00
naming_arch_mcu_board_interfaces.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
naming_os_internals.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
normal_interrupt.png Documentation: migrate "Effects of Disabling Interrupts or Pre-Emption on Response Latency" from wiki 2023-11-06 09:03:07 +08:00
nuttx_initialization_sequence.rst !arch/stm32: move stm32l1 and finalize the directory split 2026-06-24 14:54:44 -03:00
nuttx_tasking.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
oneshot_timers_and_cpu_load.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
power_management.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
preemption_latency.rst Documentation: migrate "Effects of Disabling Interrupts or Pre-Emption on Response Latency" from wiki 2023-11-06 09:03:07 +08:00
processes_vs_tasks.rst Documentation: Fix various typos 2023-11-23 16:38:19 -08:00
short_delay.png doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
short_time_delays.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
signal_handlers.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
simulation.png doc: Add NuttX Simulation page from Confluence 2024-09-09 08:40:31 +08:00
simulation.rst Dockerfile & Docs: Change bitbucket.org/nuttx/tools to github.com 2026-05-25 08:34:45 -03:00
smp.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
syslog.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
task_exit_sequence.png doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
tasks_vs_threads.rst Documentation/sched: Add POSIX user identity transition docs 2026-06-12 08:13:23 +08:00
tickless_os.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
tls.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
usb.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
user_identity.rst Documentation: describe FS permission interface and mount-crossing 2026-08-02 18:48:40 -03:00