posix: deprecate CONFIG_POSIX_API

cfriedt · cfriedt · commit 638cab4c4c15 · 2025-10-20T11:26:17.000-04:00
This change deprecates the Kconfig option `CONFIG_POSIX_API`.

It is slated for removal in Zephyr v4.5.0.

Signed-off-by: Chris Friedt &lt;cfriedt@tenstorrent.com&gt;
diff --git a/doc/services/portability/posix/kconfig/index.rst b/doc/services/portability/posix/kconfig/index.rst
@@ -19,7 +19,7 @@ implementation of the POSIX API.
 * :kconfig:option:`CONFIG_NET_SOCKETS`
 * :kconfig:option:`CONFIG_ZVFS_POLL_MAX`
 * :kconfig:option:`CONFIG_ZVFS_OPEN_MAX`
-* :kconfig:option:`CONFIG_POSIX_API`
+* :kconfig:option:`CONFIG_POSIX_SYSTEM_INTERFACES`
 * :kconfig:option:`CONFIG_POSIX_OPEN_MAX`
 * :kconfig:option:`CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_BITS`
 * :kconfig:option:`CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_DEFAULT`
diff --git a/doc/services/portability/posix/overview/index.rst b/doc/services/portability/posix/overview/index.rst
@@ -85,10 +85,10 @@ leverages the ``nanosleep()`` and ``perror()`` POSIX functions.
 .. code-block:: cfg
    :caption: `prj.conf` for a simple POSIX app in Zephyr
 
-    CONFIG_POSIX_API=y
+    CONFIG_POSIX_AEP_REALTIME_MINIMAL=y
 
 .. code-block:: c
-   :caption: A simple app that uses Zephyr's POSIX API
+   :caption: A simple app that uses the POSIX API
 
     #include <stddef.h>
     #include <stdio.h>
@@ -128,38 +128,30 @@ explicitly choose to enable POSIX options via :ref:`Kconfig<kconfig>` selection.
 Subprofiles
 +++++++++++
 
-Enable one of the Kconfig options below to quickly configure a pre-defined
+Applications should enable one of the Kconfig options below to quickly configure a pre-defined
 :ref:`POSIX subprofile <posix_subprofiles>`.
 
 * :kconfig:option:`CONFIG_POSIX_AEP_CHOICE_BASE` (:ref:`Base <posix_system_interfaces_required>`)
 * :kconfig:option:`CONFIG_POSIX_AEP_CHOICE_PSE51` (:ref:`PSE51 <posix_aep_pse51>`)
 * :kconfig:option:`CONFIG_POSIX_AEP_CHOICE_PSE52` (:ref:`PSE52 <posix_aep_pse52>`)
 * :kconfig:option:`CONFIG_POSIX_AEP_CHOICE_PSE53` (:ref:`PSE53 <posix_aep_pse53>`)
 
-Additional POSIX :ref:`Options and Option Groups <posix_option_groups>` may be enabled as needed
-via Kconfig (e.g. ``CONFIG_POSIX_C_LIB_EXT=y``). Further fine-tuning may be accomplished via
-:ref:`additional POSIX-related Kconfig options <posix_kconfig_options>`.
+Libraries should depend on :kconfig:option:`CONFIG_POSIX_SYSTEM_INTERFACES` and other
+POSIX :ref:`Option Groups <posix_option_groups>`, as needed.
 
-Subprofiles, Options, and Option Groups should be considered the preferred way to configure POSIX
-in Zephyr going forward.
+Further fine-tuning may be accomplished via
+:ref:`additional POSIX-related Kconfig options <posix_kconfig_options>`.
 
 Legacy
 ++++++
 
 Historically, Zephyr used :kconfig:option:`CONFIG_POSIX_API` to configure a set of POSIX features
 that was overloaded and always increasing in size.
 
-* :kconfig:option:`CONFIG_POSIX_API`
-
-The option is now frozen, and can be considered equivalent to the following:
-
-* :kconfig:option:`CONFIG_POSIX_AEP_CHOICE_PSE51`
-* :kconfig:option:`CONFIG_POSIX_FD_MGMT`
-* :kconfig:option:`CONFIG_POSIX_MESSAGE_PASSING`
-* :kconfig:option:`CONFIG_POSIX_NETWORKING`
+The :kconfig:option:`CONFIG_POSIX_API` is now deprecated and is slated for removal in Zephyr
+v4.5.0.
 
-However, :kconfig:option:`CONFIG_POSIX_API` should be considered legacy and should not be used for
-new Zephyr applications.
+Applications should select a POSIX subprofile mentioned above.
 
 .. _IEEE: https://www.ieee.org/
 .. _IEEE Computer Society: https://www.computer.org/
diff --git a/drivers/modem/Kconfig b/drivers/modem/Kconfig
@@ -158,7 +158,7 @@ config MODEM_SOCKET
 	  Note that the modem socket uses runtime allocated file descriptors
 	  reserved from the fdtable, for which the max count is set using the
 	  Kconfig option ZVFS_OPEN_MAX. Make sure to update this value as both
-	  the modem sockets and the POSIX_API, if used, share them.
+	  the modem sockets and other POSIX APIs, if used, share them.
 
 config MODEM_SOCKET_PACKET_COUNT
 	int "Maximum number of stored packet sizes per socket"
diff --git a/drivers/wifi/nxp/Kconfig.nxp b/drivers/wifi/nxp/Kconfig.nxp
@@ -1112,10 +1112,15 @@ if NXP_WIFI_SMOKE_TESTS
 
 config NXP_WIFI_SIGMA_AGENT
 	bool "Wi-Fi Alliance Sigma Agent Support"
-	select POSIX_API
-	select POSIX_THREADS
+	select POSIX_SYSTEM_INTERFACES
+	select POSIX_BASE_DEFINITIONS
+	select POSIX_AEP_REALTIME_MINIMAL
+	select POSIX_NETWORKING
+	imply EVENTFD
+	imply POSIX_FD_MGMT
+	imply POSIX_MULTI_PROCESS
+	imply XSI_SINGLE_PROCESS
 	select PTHREAD_CREATE_BARRIER
-	select POSIX_TIMERS
 	help
 	  This option is to enable Wi-Fi Alliance Sigma Agent support in the Wi-Fi driver.
 
diff --git a/lib/libc/common/Kconfig b/lib/libc/common/Kconfig
@@ -107,9 +107,9 @@ config COMMON_LIBC_STRNLEN
 config COMMON_LIBC_THRD
 	bool "C11 <threads.h> API support"
 	depends on DYNAMIC_THREAD
-	# Note: the POSIX_API dependency is only necessary until common elements
+	# Note: the POSIX_THREADS dependency is only necessary until common elements
 	# of C11 threads and POSIX API can be abstracted out to a common library.
-	depends on POSIX_API
+	depends on POSIX_THREADS
 	default y
 	help
 	  Common implementation of C11 <threads.h> API.
diff --git a/lib/os/Kconfig b/lib/os/Kconfig
@@ -14,7 +14,7 @@ config ZVFS_OPEN_MAX
 	int "Maximum number of open file descriptors"
 	default 24 if NRF70_ENABLE_DUAL_VIF
 	default 16 if WIFI_NM_WPA_SUPPLICANT
-	default 16 if POSIX_API
+	default 16 if POSIX_SYSTEM_INTERFACES
 	default 4
 	help
 	  Maximum number of open file descriptors, this includes
diff --git a/lib/posix/Kconfig.profile b/lib/posix/Kconfig.profile
@@ -12,11 +12,15 @@ config POSIX_API
 	imply POSIX_FD_MGMT # open(), close(), read(), write()
 	imply POSIX_MULTI_PROCESS # sleep(), getpid(), etc
 	imply XSI_SINGLE_PROCESS # gettimeofday()
+	select DEPRECATED
 	help
-	  This option enables the required POSIX System Interfaces (base definitions), all of PSE51,
-	  and some features found in PSE52.
+	  This option is deprecated. Applications should select CONFIG_POSIX_AEP_CHOICE_BASE,
+	  CONFIG_POSIX_AEP_CHOICE_PSE51, CONFIG_POSIX_AEP_CHOICE_PSE52, or
+	  CONFIG_POSIX_AEP_CHOICE_PSE53. Libraries should depend on
+	  CONFIG_POSIX_SYSTEM_INTERFACES and other POSIX Option Groups.
+
+	  For more information, please see
 
-	  Note: in the future, this option may be deprecated in favour of subprofiling options.
 
 choice POSIX_AEP_CHOICE
 	prompt "POSIX Subprofile"
diff --git a/lib/posix/options/Kconfig.fs b/lib/posix/options/Kconfig.fs
@@ -4,7 +4,7 @@
 
 menuconfig POSIX_FILE_SYSTEM
 	bool "POSIX file system API support"
-	default y if POSIX_API
+	default y if POSIX_SYSTEM_INTERFACES
 	select FILE_SYSTEM
 	select FDTABLE
 	help
diff --git a/modules/hostap/Kconfig b/modules/hostap/Kconfig
@@ -7,9 +7,13 @@
 
 config WIFI_NM_WPA_SUPPLICANT
 	bool "WPA Suplicant from hostap project [EXPERIMENTAL]"
-	select POSIX_TIMERS
-	select POSIX_SIGNALS
-	select POSIX_API
+	select POSIX_SYSTEM_INTERFACES
+	select POSIX_BASE_DEFINITIONS
+	select POSIX_AEP_REALTIME_MINIMAL
+	select POSIX_NETWORKING
+	imply EVENTFD
+	imply POSIX_FD_MGMT
+	imply POSIX_MULTI_PROCESS
 	select XSI_SINGLE_PROCESS
 	select NET_SOCKETS
 	select NET_SOCKETS_PACKET
diff --git a/modules/thrift/Kconfig b/modules/thrift/Kconfig
@@ -10,7 +10,7 @@ menuconfig THRIFT
 	depends on CPP
 	depends on STD_CPP17
 	depends on CPP_EXCEPTIONS
-	depends on POSIX_API
+	depends on POSIX_SYSTEM_INTERFACES
 	help
 	  Enable this option to support Apache Thrift
 
